10-Q

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 10-Q

☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the quarterly period ended March 31, 2024

or

☐ TRANSITION REPORTS PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the transition period from to

Commission File Number: 0-24006

NEKTAR THERAPEUTICS

(Exact name of registrant as specified in its charter)

Delaware	94-3134940
(State or other jurisdiction of incorporation or organization)	(IRS Employer Identification No.)

455 Mission Bay Boulevard South

San Francisco, California 94158

(Address of principal executive offices)

415-482-5300

(Registrant’s telephone number, including area code)

Securities registered pursuant to Section 12(b) of the Act:
Title of each class	Trading symbol(s)	Name of each exchange on which registered
Common Stock, $0.0001 par value	NKTR	NASDAQ Capital Market

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days. Yes x No ☐

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files). Yes x No ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule 12b-2 of the Exchange Act.

Large accelerated filer	☐	Accelerated filer	☒
Non-accelerated filer	☐	Smaller reporting company	☒
Emerging growth company	☐

If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act. ☐

Indicate by check mark whether the registrant is a shell company (as defined by Rule 12b-2 of the Exchange Act). Yes ☐ No ☒

The number of outstanding shares of the registrant’s Common Stock, $0.0001 par value, was 183,624,620 on May 2, 2024.

NEKTAR THERAPEUTICS

INDEX

	Summary of Risks	4
PART I: FINANCIAL INFORMATION
Item 1.	Condensed Consolidated Financial Statements — Unaudited:	6
	Condensed Consolidated Balance Sheets — March 31, 2024 and December 31, 2023	6
	Condensed Consolidated Statements of Operations for the three months ended March 31, 2024 and 2023	7
	Condensed Consolidated Statements of Comprehensive Loss for the three months ended March 31, 2024 and 2023	8
	Condensed Consolidated Statements of Stockholders’ Equity for the three months ended March 31, 2024 and 2023	9
	Condensed Consolidated Statements of Cash Flows for the three months ended March 31, 2024 and 2023	10
	Notes to Condensed Consolidated Financial Statements	11
Item 2.	Management’s Discussion and Analysis of Financial Condition and Results of Operations	23
Item 3.	Quantitative and Qualitative Disclosures About Market Risk	32
Item 4.	Controls and Procedures	32
PART II: OTHER INFORMATION
Item 1.	Legal Proceedings	33
Item 1A.	Risk Factors	33
Item 2.	Unregistered Sales of Equity Securities and Use of Proceeds	55
Item 3.	Defaults Upon Senior Securities	55
Item 4.	Mine Safety Disclosures	55
Item 5.	Other Information	55
Item 6.	Exhibits	56
Signatures		58

2

Forward-Looking Statements

This report includes “forward-looking statements” within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. All statements other than statements of historical fact are “forward-looking statements” for purposes of this Quarterly Report on Form 10-Q, including any projections of market size, earnings, revenue, milestone payments, royalties, sales or other financial items, any statements of the plans and objectives of management for future operations (including, but not limited to, preclinical development, clinical trials and manufacturing), any statements related to our financial condition and future working capital needs, any statements related to our strategic reorganization and cost restructuring plans, any statements regarding potential future financing alternatives, any statements concerning proposed drug candidates and our future research and development plans, any statements regarding the timing for the start or end of clinical trials or submission of regulatory approval filings, any statements regarding future economic conditions or performance, any statements regarding the initiation, formation, or success of any collaboration arrangements, commercialization activities and product sales levels and future payments that may come due to us under these arrangements, any statements regarding our plans and objectives to initiate or continue clinical trials, any statements related to potential, anticipated, or ongoing litigation and any statements of assumptions underlying any of the foregoing. In some cases, forward-looking statements can be identified by the use of terminology such as “believe,” “may,” “will,” “expects,” “plans,” “anticipates,” “estimates,” “potential” or “continue,” or the negative thereof or other comparable terminology. Although we believe that the expectations reflected in the forward-looking statements contained herein are reasonable, such expectations or any of the forward-looking statements may prove to be incorrect and actual results could differ materially from those projected or assumed in the forward-looking statements. Our future financial condition and results of operations, as well as any forward-looking statements, are subject to inherent risks and uncertainties, including, but not limited to, the risk factors set forth in Part I, Item 1A “Risk Factors” below and for the reasons described elsewhere in this Quarterly Report on Form 10-Q. All forward-looking statements and reasons why results may differ included in this report are made as of the date hereof and we do not intend to update any forward-looking statements except as required by law or applicable regulations. Except where the context otherwise requires, in this Quarterly Report on Form 10-Q, the “Company,” “Nektar,” “we,” “us,” and “our” refer to Nektar Therapeutics, a Delaware corporation, and, where appropriate, its subsidiaries.

Trademarks

The Nektar brand and product names, including but not limited to Nektar®, contained in this document are trademarks and registered trademarks of Nektar Therapeutics in the United States (U.S.) and certain other countries. This document also contains references to trademarks and service marks of other companies that are the property of their respective owners.

3

Summary of Risks

We are providing the following cautionary discussion of risk factors, uncertainties and assumptions that we believe are relevant to our business. These are factors that, individually or in the aggregate, we think could cause our actual results to differ materially from expected and historical results and our forward-looking statements. We note these factors for investors as permitted by Section 21E of the Exchange Act and Section 27A of the Securities Act. Investors in Nektar Therapeutics should carefully consider the risks described below before making an investment decision. You should understand that it is not possible to predict or identify all such factors. Consequently, you should not consider this section to be a complete discussion of all potential risks or uncertainties that may substantially impact our business. Moreover, we operate in a competitive and rapidly changing environment. New factors emerge from time to time and it is not possible to predict the impact of all of these factors on our business, financial condition or results of operations.

Risks to our business are more fully described below in Item IA in this Form 10-Q, which risks include, among others:

•Risks Related to our Research and Development Efforts:

oclinical drug development is a lengthy and uncertain process and we may not be able to generate and develop successful drug candidates for commercial use;

owe are highly dependent on the success of rezpegaldesleukin (previously referred to as NKTR-358) and NKTR-255 and our business will be significantly harmed if either rezpegaldesleukin or NKTR-255 do not continue to advance in clinical studies;

othe outcomes from competitive immunotherapy clinical trials, and the discovery and development of new potential immunotherapies could have a material and adverse impact on the value of our pipeline;

osignificant competition for our polymer conjugate chemistry technology platforms and our products and drug candidates could make our technologies, drug products or drug candidates obsolete or uncompetitive;

opreliminary and interim data from our clinical studies are subject to audit and verification procedures that could result in material changes in the final data and may change as more patient data become available;

oclinical trials for any of our drug candidates could be delayed for a variety of reasons, including delays associated with activating clinical sites and lower than anticipated patient enrollment rates, which are often outside of our control; and

owe depend on third parties to conduct laboratory experiments, preclinical studies and clinical trials for our biologic candidates and any failure of those parties to fulfill their obligations according to our instructions and protocol standards could harm our research and development plans and adversely affect our business.

•Risks Related to our Financial Condition and Capital Requirements:

othere is no guarantee that our prior strategic reorganization plan and cost restructuring plans will achieve their intended benefits and we may need to undertake additional cost-saving measures;

owe have substantial future capital requirements and there is a risk we may not have access to sufficient capital to meet our current business plan;

oa significant source of our revenue and capital for research and development has been derived from our collaboration agreements, and if we are unable to establish and maintain collaboration partnerships with attractive commercial terms, including significant development milestones and research and development cost-sharing, our business, results of operations and financial condition could suffer; and

owe expect to continue to incur substantial net losses from operations and may not achieve or sustain profitability in the future.

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•Risks Related to Supply and Manufacturing:

oif we or our contract manufacturers are not able to manufacture drugs or drug substances in sufficient quantities that meet applicable quality standards, our business, financial condition and results of operations could be harmed; and

owe purchase some of the starting material for drugs and drug candidates from a single source or a limited number of suppliers, and the partial or complete loss of one of these suppliers could cause delays, loss of revenue and contract liability.

•Risks Related to Intellectual Property, Litigation and Regulatory Concerns:

owe or our partners may not obtain regulatory approval for our drug candidates on a timely basis, or at all;

opatents may not issue from our patent applications for our drug candidates, patents that have issued may not be enforceable, or additional intellectual property licenses from third parties may be required, which may not be available to us on commercially reasonable terms; and

ofrom time to time, we are involved in legal proceedings and may incur substantial litigation costs and liabilities that could adversely affect our business, financial condition and results of operations.

•Risks Related to our Collaboration Partners:

owe are highly dependent on advancing rezpegaldesleukin in clinical trials, and while we believe we currently have the materials that are necessary for us to continue clinical development of rezpegaldesleukin, our ability to perform important development and regulatory activities will be significantly harmed if Eli Lilly and Company fails to continue to cooperate with us in the transfer of all materials associated with the rezpegaldesleukin program; and

owe may rely on academic and private non-academic institutions to conduct investigator-sponsored clinical studies or trials of our product candidates and any failure by the investigator-sponsor to meet its obligations with respect to the clinical development of our product candidates may delay or impair our ability to enter into collaboration agreements, obtain regulatory approval and commercialize for our product candidates.

In addition to the above-mentioned risks, our business is subject to a number of additional risks faced by businesses generally.

5

PART I: FINANCIAL INFORMATION

Item 1. Condensed Consolidated Financial Statements—Unaudited:

NEKTAR THERAPEUTICS

CONDENSED CONSOLIDATED BALANCE SHEETS

(In thousands, except par value)

(Unaudited)

	March 31, 2024			December 31, 2023
ASSETS
Current assets:
Cash and cash equivalents	$	48,642		$	35,277
Short-term investments		240,596			268,339
Accounts receivable		3,617			1,205
Inventory, net		16,238			16,101
Other current assets		10,743			9,779
Total current assets		319,836			330,701
Long-term investments		36,778			25,825
Property, plant and equipment, net		17,475			18,856
Operating lease right-of-use assets		17,267			18,007
Other assets		4,656			4,644
Total assets	$	396,012		$	398,033
LIABILITIES AND STOCKHOLDERS’ EQUITY
Current liabilities:
Accounts payable	$	8,757		$	9,848
Accrued expenses		24,281			22,162
Operating lease liabilities, current portion		19,368			19,259
Total current liabilities		52,406			51,269
Operating lease liabilities, less current portion		94,710			98,517
Liabilities related to the sales of future royalties, net		117,857			112,625
Other long-term liabilities		4,334			4,635
Total liabilities		269,307			267,046
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.0001 par value; 10,000 shares authorized; no shares designated or outstanding at March 31, 2024 or December 31, 2023, respectively		—			—
Common stock, $0.0001 par value; 300,000 shares authorized; 191,909 shares and 191,384 shares issued at March 31, 2024 and December 31, 2023, respectively; 183,624 shares and 191,384 shares outstanding at March 31, 2024 and December 31, 2023, respectively;		19			19
Capital in excess of par value		3,644,140			3,608,137
Treasury stock, at cost; 8,285 shares as of March 31, 2024 and none as of December 31, 2023, respectively		(3,000	)		—
Accumulated other comprehensive income (loss)		(403	)		80
Accumulated deficit		(3,514,051	)		(3,477,249	)
Total stockholders’ equity		126,705			130,987
Total liabilities and stockholders’ equity	$	396,012		$	398,033

The accompanying notes are an integral part of these unaudited condensed consolidated financial statements.

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NEKTAR THERAPEUTICS

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS

(In thousands, except per share information)

(Unaudited)

	Three Months Ended March 31,
	2024			2023
Revenue:
Product sales	$	6,034		$	4,718
Non-cash royalty revenue related to the sales of future royalties		15,508			16,861
License, collaboration and other revenue		97			15
Total revenue		21,639			21,594
Operating costs and expenses:
Cost of goods sold		8,534			7,060
Research and development		27,408			30,469
General and administrative		20,149			21,081
Restructuring, impairment, and costs of terminated program		975			21,193
Impairment of goodwill		—			76,501
Total operating costs and expenses		57,066			156,304
Loss from operations		(35,427	)		(134,710	)
Non-operating income (expense):
Non-cash interest expense on liabilities related to the sales of future royalties		(5,531	)		(6,405	)
Interest income		4,220			4,335
Other income (expense), net		(99	)		(301	)
Total non-operating income (expense), net		(1,410	)		(2,371	)
Loss before provision for income taxes		(36,837	)		(137,081	)
Benefit for income taxes		(35	)		(63	)
Net loss	$	(36,802	)	$	(137,018	)
Basic and diluted net loss per share	$	(0.19	)	$	(0.73	)
Weighted average shares outstanding used in computing basic and diluted net loss per share		194,746			188,875

The accompanying notes are an integral part of these unaudited condensed consolidated financial statements.

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NEKTAR THERAPEUTICS

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS

(In thousands)

(Unaudited)

	Three Months Ended March 31,
	2024			2023
Net loss	$	(36,802	)	$	(137,018	)
Other comprehensive income (loss):
Net unrealized gain (loss) on available-for-sale securities		(475	)		1,087
Net foreign currency translation gain (loss)		(8	)		139
Other comprehensive income (loss)		(483	)		1,226
Comprehensive loss	$	(37,285	)	$	(135,792	)

The accompanying notes are an integral part of these unaudited condensed consolidated financial statements.

8

NEKTAR THERAPEUTICS

CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY

(In thousands)

(Unaudited)

	Common Stock					Treasury Stock
	Shares			Amount		Shares		Amount			Capital in Excess of Par Value		Accumulated Other Comprehensive Income (Loss)			Accumulated Deficit			Total Stockholders’ Equity
Balance at December 31, 2022		188,560		$	19	$	—	$	—		$	3,574,719	$	(6,907	)	$	(3,201,193	)	$	366,638
Shares issued under equity compensation plans		675			—		—		—			—		—			—			—
Stock-based compensation		—			—		—		—			10,019		—			—			10,019
Comprehensive income (loss)		—			—		—		—			—		1,226			(137,018	)		(135,792	)
Balance at March 31, 2023		189,235		$	19	$	—	$	—		$	3,584,738	$	(5,681	)	$	(3,338,211	)	$	240,865
	Common Stock					Treasury Stock
	Shares			Amount		Shares		Amount			Capital in Excess of Par Value		Accumulated Other Comprehensive Income (Loss)			Accumulated Deficit			Total Stockholders’ Equity
Balance at December 31, 2023		191,384		$	19		—	$	—		$	3,608,137	$	80		$	(3,477,249	)	$	130,987
Shares issued under equity compensation plans		525			—		—		—			3		—			—			3
Stock-based compensation		—			—		—		—			6,000		—			—			6,000
Repurchase of common stock from Bristol-Myers Squibb		(8,285	)		—		8,285		(3,000	)		—		—			—			(3,000	)
Issuance of prefunded warrant		—			—		—		—			30,000		—			—			30,000
Comprehensive income (loss)		—			—		—		—			—		(483	)		(36,802	)		(37,285	)
Balance at March 31, 2024		183,624		$	19		8,285	$	(3,000	)	$	3,644,140	$	(403	)	$	(3,514,051	)	$	126,705

The accompanying notes are an integral part of these unaudited condensed consolidated financial statements.

9

NEKTAR THERAPEUTICS

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS

(In thousands)

(Unaudited)

	Three Months Ended March 31,
	2024			2023
Cash flows from operating activities:
Net loss	$	(36,802	)	$	(137,018	)
Adjustments to reconcile net loss to net cash used in operating activities:
Non-cash royalty revenue related to the sales of future royalties		(15,508	)		(16,861	)
Non-cash interest expense on liabilities related to the sales of future royalties		5,531			6,405
Stock-based compensation		6,000			10,019
Depreciation and amortization		1,607			2,302
Deferred income tax expense		(38	)		(1,812	)
Impairment of right-of-use assets and property, plant and equipment		—			13,200
Impairment of goodwill		—			76,501
Provision for net realizable value of inventory		1,006			952
Amortization of premiums (discounts), net and other non-cash transactions		(3,063	)		(3,129	)
Changes in operating assets and liabilities:
Accounts receivable		(2,412	)		2,986
Inventory		(1,143	)		(1,985	)
Operating leases, net		(2,958	)		(1,786	)
Other assets		(976	)		5,591
Accounts payable		(988	)		(8,920	)
Accrued expenses		1,856			1,640
Net cash used in operating activities		(47,888	)		(51,915	)
Cash flows from investing activities:
Purchases of investments		(105,059	)		(107,012	)
Maturities of investments		124,474			148,043
Purchases of property, plant and equipment		(157	)		(433	)
Net cash provided by investing activities		19,258			40,598
Cash flows from financing activities:
Proceeds from shares issued under equity compensation plans		3			—
Proceeds from issuance of pre-funded warrant		30,000			—
Proceeds from sale of future royalties		15,000			—
Repurchase of common stock from Bristol-Myers Squibb		(3,000	)		—
Net cash provided by financing activities		42,003			—
Effect of foreign exchange rates on cash and cash equivalents		(8	)		45
Net increase (decrease) in cash and cash equivalents		13,365			(11,272	)
Cash and cash equivalents at beginning of period		35,277			88,227
Cash and cash equivalents at end of period	$	48,642		$	76,955

The accompanying notes are an integral part of these unaudited condensed consolidated financial statements.

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NEKTAR THERAPEUTICS

NOTES TO CONDENSED CONSOLIDATED FINANCIAL STATEMENTS

March 31, 2024

(Unaudited)

Note 1 — Organization and Summary of Significant Accounting Policies

Organization

We are a clinical stage, research-based drug discovery biopharmaceutical company headquartered in San Francisco, California and incorporated in Delaware, focused on discovering and developing innovative medicines in the field of immunotherapy. Within this growing field, we direct our efforts toward creating new immunomodulatory agents that selectively induce, amplify, attenuate or prevent immune responses in order to achieve desired therapeutic outcomes. Our pipeline of clinical-stage and preclinical-stage immunomodulatory agents targets the treatment of autoimmune diseases (e.g. rezpegaldesleukin and NKTR-0165, respectively) and cancer (e.g. NKTR-255).

Our research and development activities have required significant ongoing investment to date and are expected to continue to require significant investment. As a result, we expect to continue to incur substantial losses and negative cash flows from operations in the future. We have financed our operations primarily through cash generated from licensing, collaboration and manufacturing agreements and financing transactions. As of March 31, 2024, we had approximately $326.0 million in cash and investments in marketable securities.

Financing Transactions

During the three months ended March 31, 2024, we entered into the following transactions:

•On February 12, 2024, for total cash consideration paid of $3.0 million, we repurchased from Bristol Myers Squibb Company (BMS) 8.3 million shares of Nektar's common stock that were previously sold to BMS, which we report as treasury stock on our Condensed Consolidated Balance Sheets. See Note 6 for additional information.

•On March 4, 2024, we entered into a Securities Purchase Agreement with TCG Crossover Fund II, L.P. (TCG), pursuant to which we issued a pre-funded warrant to TCG to purchase 25,000,000 shares of Nektar’s common stock for gross proceeds of $30.0 million (or a purchase price of $1.20 per share of common stock that can be issued upon exercise of the pre-funded warrant). See Note 5 for additional information.

•On March 4, 2024, for total cash consideration received of $15.0 million, we entered into an amendment (the Amendment) with entities managed by Healthcare Royalty Management, LLC (collectively, HCR) to remove the cap on royalties previously sold to HCR under a Purchase and Sale Agreement (the 2020 Purchase and Sale Agreement). See Note 3 for additional information.

Restructuring Plans

In April 2022, we announced the termination of the bempegaldesleukin program and a new strategic reorganization and cost restructuring plan (together, the 2022 Restructuring Plan), pursuant to which we completed an approximate 70% reduction of our workforce during 2022. We also decided to seek a sublease for certain of our leased premises in San Francisco, CA, including all of our office leased space on Third St. and portions of our office and laboratory space on Mission Bay Blvd. South.

In April 2023, we announced Eli Lilly and Company's (Lilly) decision to terminate our license agreement (the Lilly Agreement) for the development of rezpegaldesleukin, as well as a new strategic reprioritization and cost restructuring plan (the 2023 Restructuring Plan). Under the 2023 Restructuring Plan, we reduced our San Francisco-based workforce by approximately 60%. In addition, under the 2023 Restructuring Plan, we decided to seek a sublease for our remaining office and laboratory space on Mission Bay Blvd. South which we had not planned to sublease pursuant to the 2022 Restructuring Plan.

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We have regained full rights to rezpegaldesleukin from Lilly, and we initiated a Phase 2b study of rezpegaldesleukin in patients with moderate-to-severe atopic dermatitis in October 2023 and a Phase 2b study of rezpegaldesleukin in patients with severe-to-very severe alopecia areata in March 2024. We will also explore other auto-immune indications for the development of rezpegaldesleukin.

We have incurred significant costs resulting from the 2022 and 2023 Restructuring Plans. See Note 7 for additional information on the effect on our Condensed Consolidated Financial Statements.

Basis of Presentation and Principles of Consolidation

Our Condensed Consolidated Financial Statements include the financial position, results of operations and cash flows of Nektar Therapeutics and our wholly-owned subsidiaries. We have eliminated all intercompany accounts and transactions in consolidation.

We prepared our Condensed Consolidated Financial Statements following the requirements of the Securities and Exchange Commission (SEC) for interim reporting. As permitted under those rules, we may condense or omit certain footnotes or other financial information that are normally required by U.S. generally accepted accounting principles (GAAP) for annual periods. In the opinion of management, these financial statements include all normal and recurring adjustments that we consider necessary for the fair presentation of our financial position and operating results.

Our Condensed Consolidated Financial Statements are denominated in U.S. dollars. Accordingly, changes in exchange rates between the applicable foreign currency and the U.S. dollar will affect the translation of each foreign subsidiary’s financial results into U.S. dollars for purposes of reporting our consolidated financial results. We include translation gains and losses in accumulated other comprehensive loss in the stockholders’ equity section of our Condensed Consolidated Balance Sheets.

Our comprehensive loss consists of our net loss plus our foreign currency translation gains and losses and unrealized gains and losses on available-for-sale securities. There were no significant reclassifications out of accumulated other comprehensive income (loss) to the statements of operations during the three months ended March 31, 2024 and 2023.

The accompanying Condensed Consolidated Financial Statements are unaudited. The Condensed Consolidated Balance Sheet data as of December 31, 2023 was derived from the audited consolidated financial statements which are included in our Annual Report on Form 10-K for the year ended December 31, 2023 filed with the SEC on March 5, 2024. The information included in this Quarterly Report on Form 10-Q should be read in conjunction with the consolidated financial statements and the accompanying notes to those financial statements.

Revenue, expenses, assets, and liabilities can vary during each quarter of the year. The results and trends in these interim Condensed Consolidated Financial Statements are not necessarily indicative of the results to be expected for the full year or any other period.

Use of Estimates

The preparation of consolidated financial statements in conformity with U.S. generally accepted accounting principles (GAAP) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenue and expenses during the reporting period. Accounting estimates and assumptions are inherently uncertain.

Actual results could differ materially from those estimates and assumptions. As appropriate, we assess estimates each period, update them to reflect current information, and generally reflect any changes in estimates in the period first identified.

Significant Concentrations

Our customers are primarily pharmaceutical companies that are located in the U.S. and Europe and with whom we have multi-year arrangements. Our accounts receivable balance contains billed and unbilled trade receivables from product sales, milestones (to the extent that they have been achieved and are due from the counterparty), and other contingent payments, as well as reimbursable costs from collaborative research and development agreements. We generally do not require collateral from our

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customers. We perform a regular review of our customers’ credit risk and payment histories, including payments made after period end. Historically, we have not experienced credit losses from our accounts receivable. We have not recorded reserves for credit losses for the three months ended March 31, 2024 and 2023, nor have recorded such an allowance as of March 31, 2024 or December 31, 2023.

We are dependent on our suppliers and contract manufacturers to provide raw materials and drugs of appropriate quality and reliability and to meet applicable contract and regulatory requirements. In certain cases, we rely on single sources of supply of one or more critical materials. Consequently, in the event that supplies are delayed or interrupted for any reason, our ability to develop and produce our drug candidates or our ability to meet our supply obligations could be significantly impaired, which could have a material adverse effect on our business, financial condition and results of operations.

For our available-for-sale securities, we have significant concentrations of issuers in the banking and financial services industries. While our investment policy requires that we only invest in highly-rated securities and limit our exposure to any single issuer, various factors may materially affect the financial condition of issuers. Additionally, pursuant to our investment policy, we may sell securities before maturity if the issuer’s credit rating has been downgraded below our minimum credit rating requirements, which may result in a loss on the sale. Accordingly, if various factors result in downgrades below our minimum credit rating requirements and if we decide to sell these securities, we may experience losses on such sales.

Treasury Stock

We record treasury stock activities under the cost method. Treasury stock is included in authorized and issued shares but excluded from outstanding shares. The re-issuance of treasury stock is accounted for on a first in, first-out basis and any differences between the cost of treasury stock and the re-issuance proceeds are charged or credited to additional paid-in capital.

Restructuring

We recognize restructuring charges related to reorganization plans that have been committed to by management when liabilities have been incurred. In connection with these activities, we record restructuring charges at fair value for:

•contractual or other employee termination benefits provided that the obligations result from services already rendered based on rights that vest or accumulated when the payment of benefits becomes probable and the amount can be reasonably estimated,

•one-time employee termination benefits on the communication date from management to the employees provided that management has committed to a plan of termination, the plan identifies the employees and their expected termination dates, the details of termination benefits are complete, and it is unlikely that changes to the plan will be made or the plan will be withdrawn,

•contract termination costs when we cancel the contract in accordance with its terms, and

•costs to be incurred over the remaining contract term without economic benefit to us at the cease-use date.

For one-time employee terminations benefits, we recognize the liability in full on the communication date when future services are not required or amortize the liability ratably over the service period, if required. The fair value of termination benefits reflects our estimates of expected utilization of certain Company-funded post-employment benefits.

See Note 7 for additional information on the severance expense that we recognized for employees terminated in connection with our reductions-in-force.

Impairment of Goodwill

Goodwill is assessed for impairment on an annual basis and whenever events and circumstances indicate that it may be impaired. Factors that may indicate potential impairment and trigger an impairment test include, but are not limited to, current economic, market and geopolitical conditions, including a significant, sustained decline in our stock price and market

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capitalization compared to the net book value; an adverse change in legal factors, business climate or operational performance of the business; or significant changes in the ability of the reporting unit to generate positive cash flows for our strategic business objectives. If the carrying value of the reporting unit, including goodwill, exceeds the reporting unit’s fair value, we will recognize a goodwill impairment loss, and we will write down goodwill such that the carrying value of the reporting unit equals its fair value, provided that we cannot reduce goodwill below zero.

See Note 8 for additional information regarding the impairment charges we recorded during the three months ended March 31, 2023 in connection with our goodwill.

Long-Lived Asset Impairment

We assess the impairment of long-lived assets whenever events or changes in business circumstances indicate that the carrying amounts of the assets may not be fully recoverable. In the case of property, plant and equipment and right-of-use assets for our leases, we determine whether there has been an impairment by comparing the carrying value of the asset to the anticipated undiscounted net cash flows associated with the asset. If such cash flows are less than the carrying value, we write down the asset to its fair value, which may be measured as anticipated net cash flows associated with the asset, discounted at a rate that we believe a market participant would utilize to reflect the risks associated with the cash flows, such as credit risk.

See Note 7 for additional information regarding the impairment charges we recorded in connection with our leased facilities and certain property and equipment.

Net Loss per Share

For all periods presented in the Condensed Consolidated Statements of Operations, the net loss available to common stockholders is equal to the reported net loss. We calculate basic net loss per share based on the weighted-average number of common shares outstanding, including the pre-funded warrant, during the periods presented. Shares of common stock into which the pre-funded warrant may be exercised are considered outstanding for the purposes of computing basic net loss per share because the shares may be issued for little or no consideration, are fully vested and are exercisable after the original issuance date. For the three months ended March 31, 2024 and 2023, basic and diluted net loss per share are the same due to our net losses and the requirement to exclude potentially dilutive securities which would have an antidilutive effect on net loss per share. We excluded shares underlying the weighted average outstanding stock options, restricted stock units (RSUs) and performance stock units (PSUs), as follows (in thousands):

	Three Months Ended March 31,
	2024		2023
Potentially dilutive securities		26,973		22,798

Note 2 — Cash and Investments in Marketable Securities

Cash and investments in marketable securities, including cash equivalents, are as follows (in thousands):

	Estimated Fair Value at
	March 31, 2024		December 31, 2023
Cash and cash equivalents	$	48,642	$	35,277
Short-term investments		240,596		268,339
Long-term investments		36,778		25,825
Total cash and investments in marketable securities	$	326,016	$	329,441

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Our portfolio of cash and investments in marketable securities includes (in thousands):

		March 31, 2024									December 31, 2023
	Fair Value Hierarchy Level	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value		Fair Value
Corporate notes and bonds	2	$	75,745	$	2	$	(163	)	$	75,584	$	38,882
Corporate commercial paper	2		211,955		—		(261	)		211,694		255,241
Obligations of U.S. government agencies	2		3,457		—		(3	)		3,454		—
Available-for-sale investments		$	291,157	$	2	$	(427	)	$	290,732	$	294,123
Money market funds	1									15,959		2,359
Certificates of deposit	2									13,898		15,116
Cash	N/A									5,427		17,843
Total cash and investments in marketable securities									$	326,016	$	329,441

For the three months ended March 31, 2024 and 2023, there were no transfers between Level 1 and Level 2 of the fair value hierarchy. At December 31, 2023, our gross unrealized gains and losses were insignificant.

Note 3 — Condensed Consolidated Financial Statement Details

Inventory

Inventory consists of the following (in thousands):

	March 31, 2024		December 31, 2023
Raw materials	$	1,936	$	1,861
Work-in-process		9,962		12,880
Finished goods		4,340		1,360
Total inventory, net	$	16,238	$	16,101

We manufacture finished goods inventory upon receipt of firm purchase orders, and we may manufacture certain intermediate work-in-process materials and purchase raw materials based on purchase forecasts from our partners. We include direct materials, direct labor, and manufacturing overhead in inventory and determine cost on a first-in, first-out basis for raw materials and on a specific identification basis for work-in-process and finished goods. We value inventory at the lower of cost or net realizable value, and we write down defective or excess inventory to net realizable value based on historical experience or projected usage. We expense inventory related to our research and development activities as manufactured by us or when purchased.

As of March 31, 2024 and December 31, 2023, we recorded a provision of $2.4 and $2.0 million, respectively, for the net realizable value of our batches. Our manufacturing agreement with UCB Pharma (UCB) provides for a fixed selling price which we had negotiated in exchange for a higher royalty rate. Accordingly, when evaluating the net realizable value of our inventory for UCB, we include the negotiated increase of the royalties in our analysis, and the aggregate revenue has historically been greater than our manufacturing cost. Due to the decreases in the royalty rate for 2024 and 2025 as a result of a settlement agreement with UCB, the aggregate revenue is expected to be less than our manufacturing cost, and therefore we recorded a provision for net realizable value.

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Other Current Assets

Other current assets consist of the following (in thousands):

	March 31, 2024		December 31, 2023
Prepaid research and development expenses	$	4,767	$	4,325
Non-trade receivables and other		1,816		1,047
Other prepaid expenses		4,160		4,407
Total other current assets	$	10,743	$	9,779

Accrued Expenses

Accrued expenses consist of the following (in thousands):

	March 31, 2024		December 31, 2023
Accrued compensation	$	7,384	$	5,553
Accrued clinical trial expenses		4,233		4,321
Liability to collaboration partners		1,310		2,678
Accrued contract termination costs		3,043		3,020
Other accrued expenses		8,311		6,590
Total accrued expenses	$	24,281	$	22,162

Liabilities Related to the Sales of Future Royalties

In 2012 and 2020, we sold to RPI Finance Trust (RPI) and HCR, respectively, our rights to receive royalties under our license and manufacturing agreements with certain pharmaceutical partners under the 2012 Purchase and Sale Agreement and the 2020 Purchase and Sale Agreement, respectively. We account for these transactions as debt and recognize non-cash royalty revenue and non-cash interest expense to amortize the proceeds over the lives of the respective arrangements. We periodically update our prospective non-cash interest rate based on our estimates of future royalties. As of March 31, 2024, our imputed interest rates for the arrangements with RPI and HCR were 30% and 19%, respectively.

The original 2020 Purchase and Sale Agreement was to expire -- and wherein the right to receive royalties would revert to us -- if HCR received aggregate royalties of $210.0 million on or prior to December 31, 2025 (the 2025 Threshold), or, if the 2025 Threshold was not achieved by December 31, 2025, when HCR received aggregate royalties of $240.0 million. On March 4, 2024, Nektar and HCR amended the original 2020 Purchase and Sale Agreement (the Amendment), pursuant to which the parties agreed to remove our reversionary rights in the royalties in exchange for a $15.0 million payment from HCR. Accordingly, HCR will receive all future royalties of the products, and none of these royalties will return to Nektar. We concluded that we should account for the Amendment as a modification of the existing arrangement, and therefore recorded the $15.0 million proceeds as an increase to the liability. We included the effects of the Amendment in determining our imputed interest rate of 19% as of March 31, 2024.

The following is a reconciliation of the changes in our liabilities related to the sales of future royalties for the three months ended March 31, 2024 (in thousands):

	Three Months Ended March 31, 2024
	2012 Purchase and Sale Agreement			2020 Purchase and Sale Agreement			Total
Liabilities related to the sales of future royalties, net – beginning balance	$	24,217		$	88,408		$	112,625
Non-cash royalty revenue		(6,944	)		(8,564	)		(15,508	)
Non-cash interest expense		1,831			3,700			5,531
Amortization of transaction costs		—			209			209
Proceeds from the Amendment		—			15,000			15,000
Liabilities related to the sales of future royalties, net – ending balance	$	19,104		$	98,753		$	117,857

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Note 4 — Commitments and Contingencies

Legal Matters

From time to time, we are involved in lawsuits, arbitrations, claims, investigations and proceedings, consisting of intellectual property, commercial, employment and other matters, which arise in the ordinary course of business. We make provisions for liabilities when it is both probable that a liability has been incurred and the amount of the loss can be reasonably estimated. Such provisions are reviewed at each reporting date and adjusted to reflect the impact of settlement negotiations, judicial and administrative rulings, advice of legal counsel, and other information and events pertaining to a particular case. Litigation is inherently unpredictable. If any unfavorable ruling were to occur in any specific period, there exists the possibility of a material adverse impact on the results of our operations for that period and on our cash flows and liquidity.

On August 7, 2023, we filed a complaint in the United States District Court for the Northern District of California (the Court) against Lilly alleging, among other claims, breach of contract and breach of implied covenant of good faith and fair dealing (the Complaint), in connection with our collaboration with Lilly. Following the denial of its motion to dismiss the Complaint entirely, Lilly filed an answer that included counterclaims against us alleging breach of specified confidentiality provisions and defamation. The case is proceeding.

We have recorded no liability for any litigation matters in our Condensed Consolidated Balance Sheets at either March 31, 2024 or December 31, 2023.

Indemnifications in Connection with Commercial Agreements

As part of our collaboration agreements with our partners related to the license, development, manufacture and supply of drugs and PEGylation materials based on our proprietary technologies and drug candidates, we generally agree to defend, indemnify and hold harmless our partners from and against third party liabilities arising out of the agreement, including product liability (with respect to our activities) and infringement of intellectual property to the extent the intellectual property is developed by us and licensed to our partners. The term of these indemnification obligations is generally perpetual commencing after execution of the agreement. There is generally no limitation on the potential amount of future payments we could be required to make under these indemnification obligations.

From time to time, we enter into other strategic agreements such as divestitures and financing transactions pursuant to which we are required to make representations and warranties and undertake to perform or comply with certain covenants. For example, we made certain intellectual property representations in connection with our RPI and HCR transactions, however, the time limitation we have to indemnify RPI with respect to any breach of these intellectual property-based representations and warranties has passed. In the event it is determined that we breached certain of the representations and warranties or covenants made by us in any such agreements or certain express indemnification provisions are applicable, we could incur substantial indemnification liabilities depending on the timing, nature, and amount of any such claims.

To date, we have not incurred any costs to defend lawsuits or settle claims related to these indemnification obligations, nor any breaches of representations or warranties or covenants. Because the aggregate amount of any potential indemnification obligation is not a stated amount, we cannot reasonably estimate the overall maximum amount of any such obligations.

Note 5 — Pre-Funded Warrant

In March 2024, we issued a pre-funded warrant to purchase an aggregate of 25,000,000 shares of our common stock to TCG at a price of $1.20 per share for gross proceeds of $30.0 million. Transaction costs were immaterial. The pre-funded warrant has an exercise price of $0.0001 per share and may be exercised at any time after the original issuance date. TCG may not exercise the warrant if TCG, together with its affiliates, would beneficially own more than 9.99% of the number of shares of our common stock outstanding immediately after giving effect to such exercise. TCG may increase or decrease this percentage not in

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excess of 19.99% by providing at least 61 days’ prior notice to the Company. As of March 31, 2024, the warrant has not been exercised.

We classified the pre-funded warrant as a component of permanent equity in our Condensed Consolidated Balance Sheets as it is a freestanding financial instrument that was immediately exercisable, does not embody an obligation for the Company to repurchase its own shares and permits the holder to receive a fixed number of shares of common stock upon exercise. All of the shares underlying the pre-funded warrant have been included in the weighted-average number of shares of common stock used to calculate net loss per share attributable to common stockholders because the shares may be issued for little or no consideration, are fully vested and are exercisable after the original issuance date of the pre-funded warrant.

Note 6 — License and Collaboration Agreements

We have entered into various collaboration agreements including license agreements and collaborative research, development and commercialization agreements with various pharmaceutical and biotechnology companies. Under these collaboration arrangements, we are entitled to receive license fees, upfront payments, milestone and other contingent payments, royalties, sales milestone payments, and payments for the manufacture and supply of our proprietary PEGylation materials and/or reimbursement for research and development activities. We generally include our costs of performing these services in research and development expense, except for costs for product sales to our collaboration partners which we include in cost of goods sold. We analyze our agreements to determine whether we should account for the agreements within the scope of ASC 808 Collaborative Arrangements, and, if so, we analyze whether we should account for any elements under ASC 606 Revenue from Contracts with Customers.

Eli Lilly and Company (Lilly): Rezpegaldesleukin (previously referred to as NKTR-358)

On July 23, 2017, we entered into a worldwide license agreement (the Lilly Agreement) with Lilly to co-develop rezpegaldesleukin, a novel immunological drug candidate that we invented, pursuant to which we received an initial payment of $150.0 million and were eligible for up to $250.0 million in additional development and regulatory milestones. The Lilly Agreement provided that, during Phase 1B and Phase 2 development, we shared development costs wherein 75% of the costs were borne by Lilly and 25% of the costs were borne by us.

On April 23, 2023, we received from Lilly a notice of at-will termination of the Lilly Agreement. We have regained full rights to rezpegaldesleukin from Lilly, and the Lilly Agreement subsequently terminated. Following the return of our rights to develop rezpegaldesleukin, we bear all costs of development. We initiated a Phase 2b study of rezpegaldesleukin in patients with moderate-to-severe atopic dermatitis in October 2023 and a Phase 2b study of rezpegaldesleukin in patients with severe-to-very severe alopecia areata in March 2024. We will also explore other auto-immune indications for the development of rezpegaldesleukin.

Bristol-Myers Squibb Company (BMS): Bempegaldesleukin, also referred to as NKTR-214

Effective April 3, 2018, we entered into a Strategic Collaboration Agreement (the BMS Collaboration Agreement) and a Share Purchase Agreement with BMS. Pursuant to the BMS Collaboration Agreement, we and BMS jointly developed bempegaldesleukin in combination with BMS’ Opdivo®. The parties shared the internal and external development costs for bempegaldesleukin in combination regimens based on each party’s relative ownership interest in the compounds included in the regimens.

Upon the effective date of the BMS Collaboration Agreement in April 2018, BMS paid us a non-refundable upfront cash payment of $1.0 billion and purchased 8,284,600 shares of our common stock pursuant to the Share Purchase Agreement for total additional cash consideration of $850.0 million. In 2020, we received additional non-refundable milestone payments of $50.0 million.

In April 2022, we announced that BMS and we decided to discontinue all development of bempegaldesleukin in combination with Opdivo®. On September 6, 2023, BMS and we terminated the BMS Collaboration Agreement, and pursuant to the surviving provisions of the BMS Collaboration Agreement, we and BMS continue our efforts to wind down the

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bempegaldesleukin program, and the cost sharing provisions continue to remain in effect as the parties wind down the studies. On February 12, 2024, we repurchased the 8.3 million shares previously sold to BMS for total cash consideration of $3.0 million.

We determined that the BMS Collaboration Agreement falls within the scope of ASC 808. Based on the cost sharing percentages described above, we recognize the net reimbursement to (from) BMS as an increase (decrease) to the applicable expense. As discussed in Note 7, beginning in the second quarter of 2022, we began reporting clinical trial, other third-party costs and employee costs for the wind down of the bempegaldesleukin program in restructuring, impairment and costs of terminated program. For the three months ended March 31, 2024, such amounts are immaterial and are included in research and development expense.

Other

We have other collaboration agreements that have resulted in commercialized products for our collaborations partners. Under these agreements, we may sell our proprietary PEGylation materials for use in these products, and we are entitled to receive royalties based on net sales of these products as well as sales milestones. As discussed in Note 3, we have sold our rights to receive royalties from these other collaboration agreements. Our non-cash royalty revenue, which totaled $16.9 million for the three months ended March 31, 2023, and totaled $15.5 million for the three months ended March 31, 2024, represents revenue for granting licenses which we had satisfied in prior periods.

Additionally, we have a collaboration agreement for a product under development, under which we are entitled to up to a total of $40.0 million of regulatory milestones, as well as royalties based on net sales of commercialized products, if any. However, given the current phase of development of the potential product under this collaboration agreement, we cannot estimate the probability or timing of achieving these milestones, and, therefore, have excluded all development milestones from the transaction price for this agreement.

Note 7 — Restructuring, Impairment and Costs of Terminated Program, and Impairment of Goodwill

Restructuring, Impairment and Costs of Terminated Program

In connection with our 2022 and 2023 Restructuring Plans, we report the following costs in restructuring, impairment and costs of terminated program:

•Clinical trial expense, other third-party costs and employee costs for the wind down of the bempegaldesleukin program, net of the reimbursement from BMS, initiated in 2022;

•Severance and related benefit costs pursuant to the 2022 and 2023 Restructuring Plans;

•Non-cash impairment of right-of-use assets and property, plant and equipment; and

•Contract termination and other costs associated with these plans.

Restructuring, impairment and costs of terminated program includes the following (in thousands):

	Three Months Ended March 31,
	2024		2023
Clinical trial expense, other third-party and employee costs for the wind down of the bempegaldesleukin program	$	—	$	1,598
Severance and benefit expense		—		5,483
Impairment of right-of-use assets and property, plant and equipment		—		13,200
Contract termination and other restructuring costs		975		912
Restructuring, impairment and other costs of terminated program	$	975	$	21,193

Wind Down of the Bempegaldesleukin Program

In prior periods through March 31, 2022, we reported the clinical trial costs, other third-party costs and employee costs related to the bempegaldesleukin program primarily in research and development expense. Beginning in the second quarter of

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2022, following our announcement to terminate the program, we began reporting clinical trial, other third-party costs and employee costs for the wind down of the bempegaldesleukin program in restructuring, impairment and costs of terminated program. For the three months ended March 31, 2024, such amounts are immaterial and are included in research and development expense.

Severance and Benefit Expense

Employees affected by the reduction in force under the 2022 and 2023 Restructuring Plans are entitled to receive severance payments and certain Company funded benefits. The restructuring charges are recorded at fair value.

For the 2022 Restructuring Plan, we recognized all expense in 2022 and paid the final liability of $3.3 million in the three months ended March 31, 2023.

For the 2023 Restructuring Plan, we recognized a liability of $5.5 million of severance and benefit expense as of March 31, 2023, reflecting severance and benefits which the employees had vested into and for which payment was probable and reasonably estimable as of March 31, 2023. We recognized $7.9 million in total expense in 2023 for the 2023 Restructuring Plan and paid the final liability of $0.2 million in the three months ended March 31, 2024.

We do not expect to recognize any additional severance and benefits expense for the 2022 and 2023 Restructuring Plans.

The following table provides details regarding the severance and benefit expense for the three months ended March 31, 2024 pursuant to the 2023 Restructuring Plan and a reconciliation of the severance and benefits liability for the three months ended March 31, 2023 pursuant to the 2022 and 2023 Restructuring Plans, which we report within accrued expenses on our Condensed Consolidated Balance Sheet (in thousands):

	Three Months Ended March 31, 2023
	2023 Restructuring Plan			2022 Restructuring Plan			Total
Liability balance as of December 31, 2022	$	—		$	3,299		$	3,299
Expense recognized during the period		5,483			—			5,483
Payments during the period		—			(3,299	)		(3,299	)
Liability balance as of March 31, 2023	$	5,483		$	—		$	5,483
	Three Months Ended March 31, 2024
	2023 Restructuring Plan			2022 Restructuring Plan			Total
Liability balance as of December 31, 2023	$	196		$	—		$	196
Expense recognized during the period		—			—			—
Payments during the period		(196	)		—			(196	)
Liability balance as of March 31, 2024	$	—		$	—		$	—

Impairment of Long-Lived Assets

As a result of our 2022 and 2023 Restructuring Plans, we decided to seek a sublease for all of our leased spaces on Third Street and Mission Bay Blvd. South. Accordingly, we evaluate each space for impairment when management decides to sublease the respective space and at each reporting date thereafter, as facts and circumstances change. The significant assumptions in our impairment analysis relate to sublease income, including the length of time to enter into a sublease, sublease rental payments, free rent periods, tenant improvement allowances and broker commissions. When available, we use sublease negotiations or agreements, but in the absence of such information, we develop our own subjective estimates based on current real estate trends and market conditions. Accordingly, our estimates are subject to significant risk, and the terms of sublease agreements, if any, and the resulting amount and timing of sublease income, if ever realized, may be materially different than our estimates.

As part of our evaluation of each sublease space, we separately compare the estimated undiscounted sublease income, as described above, for each sublease to the net book value of the related long-term assets, which include right-of-use assets and

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certain property, plant and equipment, primarily for leasehold improvements (collectively, sublease assets). If such sublease income exceeds the net book value of the sublease assets, we do not record an impairment charge. Otherwise, we record an impairment charge by reducing the net book value of the sublease assets to their estimated fair value, which we determined by discounting the estimated sublease income using the estimated borrowing rate of a market participant subtenant, which we estimated to be 7.9%, for the three months ended March 31, 2023.

During the three months ended March 31, 2023, we recorded an impairment charge for our remaining office and laboratory leased space in our Mission Bay Blvd. South facility which we decided to sublease under the 2023 Restructuring Plan. We also recorded impairment charges for certain excess laboratory equipment which we subsequently sold in 2023.

During the three months ended March 31, 2024, while we continue to seek subleases for our office lease space on Third. St. and our office and laboratory lease space on Mission Bay Blvd. South, we recorded no impairment charges during the three months ended March 31, 2024.

The following is a reconciliation of the impairment charges we recorded for the three months ended March 31, 2023, including the net book values of the sublease assets before the impairment and the fair values of the sublease assets (in thousands):

	Three Months Ended March 31, 2023
	Property, Plant and Equipment			Operating Lease Right-of-Use Assets			Total
Net book value of impaired facilities before write-off	$	5,114		$	28,434		$	33,548
Less: Fair value of impaired facilities — Level 3 of Fair Value Hierarchy		(3,314	)		(18,734	)		(22,048	)
Impairment expense for facilities		1,800			9,700			11,500
Impairment of other property, plant and equipment		1,700			—			1,700
Total impairment of right-of-use assets and property, plant and equipment	$	3,500		$	9,700		$	13,200

Contract Termination and Other Costs

We have incurred significant contract termination costs in connection with our 2022 Restructuring Plan. Because we adjust this liability at fair value at each reporting date, we continue to recognize expense as our estimates change until settlement.

The following are reconciliations of the contract termination and other costs for the 2022 Restructuring Plan for the three months ended March 31, 2024 and 2023. We report $3.0 million within accrued expenses and the remaining within other long-term liabilities on our Condensed Consolidated Balance Sheets as of March 31, 2024 and December 31, 2023.

	For the Three Months Ended March 31,
	2024			2023
Liability balances as of December 31, 2023 and December 31, 2022, respectively	$	5,542		$	7,710
Expense recognized during the period		975			878
Payments during the period		(928	)		(1,095	)
Liability balances as of March 31, 2024 and March 31, 2023, respectively	$	5,589		$	7,493

Note 8 — Impairment of Goodwill

During the three months ended March 31, 2023, our stock price and resulting market capitalization experienced a significant, sustained decline. Accordingly, we assessed our long-lived assets, including our property, plant and equipment, right-of-use assets and goodwill, for impairment.

As part of our long-lived asset impairment analysis, we first assessed which long-lived assets have identifiable cash flows that are largely independent of the cash flows of other groups of assets. We concluded that the sublease assets, for which we recognized significant impairment charges during 2022 and 2023, including for the three months ended March 31, 2023, are

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independent of our entity-wide group. See Note 7 for additional information regarding impairment charges that we have recorded for our sublease assets, as well as certain property, plant and equipment that we subsequently sold.

We next evaluated our remaining long-lived assets for impairment and performed a recoverability test using the undiscounted cash flows approach. We did not recognize any additional impairment charges on the remaining long-lived assets.

Finally, we measured the fair value of our reporting unit utilizing both income and market approaches for our entity-wide asset impairment analysis. Based on this analysis, we wrote off all of our goodwill, resulting in a non-cash impairment charge of $76.5 million which we reported as impairment of goodwill in our Condensed Consolidated Statements of Operations for the three months ended March 31, 2023. We had previously recognized goodwill primarily from our acquisitions of Shearwater Corp. and Aerogen, Inc. in 2001 and 2005, respectively.

Note 9 — Stock-Based Compensation

We recognized total stock-based compensation expense in our Condensed Consolidated Statements of Operations as follows (in thousands):

	Three Months Ended March 31,
	2024		2023
Cost of goods sold	$	633	$	812
Research and development		2,280		4,146
General and administrative		3,087		5,061
Total stock-based compensation	$	6,000	$	10,019

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Item 2. Management’s Discussion and Analysis of Financial Condition and Results of Operations

The following discussion contains forward-looking statements that involve risks and uncertainties. Our actual results could differ materially from those discussed here. Factors that could cause or contribute to such differences include, but are not limited to those discussed in this section as well as factors described in Part II, Item 1A “Risk Factors.”

Overview

Strategic Direction of Our Business

Nektar Therapeutics is a clinical stage, research-based drug discovery biopharmaceutical company focused on discovering and developing innovative medicines in the field of immunotherapy. Within this growing field, we direct our efforts toward creating new immunomodulatory agents that selectively induce, amplify, attenuate or prevent immune responses in order to achieve desired therapeutic outcomes. We apply our deep understanding of immunology and unparalleled expertise in polymer chemistry to create innovative drug candidates and use our drug development expertise to advance these molecules through preclinical and clinical development. Our pipeline of clinical-stage and preclinical-stage immunomodulatory agents targets the treatment of autoimmune diseases (e.g. rezpegaldesleukin and NKTR-0165, respectively) and cancer (e.g. NKTR-255). We continue to make significant investments in building and advancing our pipeline of drug candidates as we believe that this is the best strategy to build long-term shareholder value.

In April of 2022 and 2023, we implemented the 2022 Restructuring Plan and 2023 Restructuring Plan, respectively, which both prioritized key research and development efforts that will be most impactful to the Company’s future. Central to both plans is the continuation of clinical development of both rezpegaldesleukin (previously referred to as NKTR-358) and NKTR-255 programs as well as our core research programs in immunology that include a separate tumor necrosis factor receptor 2 agonist antibody (NKTR-0165).

Autoimmune and inflammatory diseases cause the immune system to mistakenly attack and damage healthy cells in a person’s body. A failure of the body’s self-tolerance mechanisms enables the formation of the pathogenic T lymphocytes that conduct this attack. Our drug candidate rezpegaldesleukin is a potential first-in-class resolution therapeutic that may address this underlying immune system imbalance in people with autoimmune disorders and inflammatory diseases. It is designed to target the interleukin-2 (IL-2) receptor complex in the body in order to stimulate proliferation of powerful inhibitory immune cells known as regulatory T cells (Treg cells). By activating these cells, rezpegaldesleukin may act to bring the immune system back into balance. Rezpegaldesleukin is being developed as a once or twice monthly self-administered injection for a number of autoimmune disorders and inflammatory diseases.

On October 13, 2023, we announced final efficacy data from a Phase 1b study of rezpegaldesleukin in adult patients with atopic dermatitis (Phase 1b AD Study) at the European Academy of Dermatology and Venereolgy conference. The final efficacy data from the Phase 1b AD study showed that patients with moderate-to-severe atopic dermatitis that were treated with rezpegaldesluekin had dose-dependent improvements in the eczema area and severity index (EASI), validated investigated global assessment (vIGA), body surface area (BSA), and itch numeric rating scale (NRS) over twelve weeks of treatment compared to placebo, which were sustained post-treatment over an additional thirty-six weeks. Rezpegaldesleukin was well tolerated with no patients in the rezpegaldesleukin groups experiencing severe, serious, or fatal adverse events, and no anti-rezpegaldesleukin antibodies were detected.

In late October 2023, we initiated a Phase 2b clinical study of rezpegaldesleukin in patients with moderate-to-severe atopic dermatitis, and in Mach 2024, we initiated a Phase 2b clinical study in patients with severe-to-very severe alopecia areata. We also plan to explore other auto-immune indications for the development of rezpegaldesleukin. We developed rezpegaldesleukin and currently own full rights to this drug candidate. Although we previously entered into a license agreement with Eli Lilly and Company in 2017 (the Lilly Agreement) to develop and commercialize rezpegaldesleukin, on April 23, 2023, we received from Lilly a notice of at-will termination of the Lilly Agreement, and on April 27, 2023, we announced that we would be regaining full rights to rezpegaldesleukin.

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In oncology, we focus on developing medicines that target biological pathways that stimulate and sustain the body’s immune response in order to fight cancer. Our drug candidate NKTR-255 is an investigational biologic that is designed to target the IL-15 pathway in order to activate the body’s innate and adaptive immunity. Through optimal engagement of the IL-15 receptor complex, NKTR-255 is designed to enhance functional NK cell populations and formation of long-term immunological memory, which may lead to sustained and durable anti-tumor immune response. We are continuing select developmental studies of NKTR-255 in combination with cell therapies and checkpoint inhibitors while we evaluate additional strategic partnership pathways for the program.

We initiated a Nektar-sponsored Phase 2 study to evaluate NKTR-255 following Yescarta® or Breyanzi® CD19 CAR-T cell therapy in patients with large B-cell lymphoma, and the Fred Hutchinson Cancer Center is evaluating NKTR-255 following Breyanzi® CD19 CAR-T cell therapy in patients with relapsed/refractory large B-cell lymphoma as an investigator sponsored study. We are continuing our oncology clinical collaboration with Merck KGaA to evaluate the maintenance regimen of NKTR-255 in combination with avelumab, a PD-L1 inhibitor, in patients with locally advanced or metastatic urothelial carcinoma in the Phase II JAVELIN Bladder Medley study. We expect to receive topline data from this study in the second half of 2024. We entered into a new clinical study collaboration with AbelZeta Pharma, Inc. (AbelZeta) (formerly known as CBMG Holdings) to study NKTR-255 in combination with its C-TIL051, a tumor-infiltrating lymphocyte (TIL) therapy, in advanced non-small cell lung cancer (NSCLC) patients that are relapsed or refractory to anti-PD-1 therapy. Under the collaboration, we will contribute NKTR-255 and AbelZeta will add NKTR-255 to its ongoing AbelZeta-sponsored Phase 1 clinical trial. We also have an ongoing investigator sponsored study evaluating NKTR-255 in combination with IMFINZI (durvalumab) in patients with unresectable Stage 3 NSCLC who have received chemoradiation.

We continue to advance our most promising research drug candidates into preclinical development with the objective of advancing these early-stage research programs to human clinical studies over the next several years. Our lead research program, NKTR-0165, is our preclinical tumor necrosis factor (TNF) receptor type II (TNFR2) agonist asset, which we believe is a unique bivalent antibody that selectively stimulates TNFR2 receptor activity, without modulation of the TNFR1 signaling. TNFR2 signaling drives immunoregulatory function and can provide a direct protective effect for tissue cells. TNFR-2 is highly expressed on Tregs, neuronal cells and endothelial cells and has been shown to potentiate the suppressive effects and overall functional properties of Tregs. Our focus on TNFR2 antibody candidates that show selective Treg cell binding and signaling profiles that may be developed for treatment of autoimmune diseases, such as ulcerative colitis, multiple sclerosis and vitiligo. We are carrying out Investigational New Drug (IND) enabling studies for this program in 2024, after having exercised an option in December 2023 to gain an exclusive license to specified agonistic antibodies and other materials that were developed pursuant to a research collaboration and license option agreement we entered into with Biolojic Design, Ltd. in 2021.

We have historically derived substantially all of our revenue and significant amounts of research and development operating capital from our collaboration agreements. In addition to payments received under the Lilly Agreement, we have received upfront and milestone payments and cost-sharing reimbursements under a number of other previous collaboration agreements, and certain of our collaboration partners have borne substantial costs of developing our drug candidates. Following the return of our rights to develop rezpegaldesleukin from Lilly, unless we enter into a new collaboration agreement, we will bear all the costs of developing our pipeline drug candidates, other than our clinical collaborations for NKTR-255 described above.

Several of our historical collaboration agreements have resulted in approved drugs, for which we may continue to manufacture the polymer reagents used in the production of the drug products and may be entitled to royalties for net sales of these approved drugs. However, we have sold our rights to receive royalties under these arrangements, including:

•2012 Purchase and Sale Agreement: In 2012, we sold all of our rights to receive royalties from CIMZIA® (for the treatment of Crohn’s disease and other autoimmune indications) and MIRCERA® (for the treatment of anemia associated with chronic kidney disease) under our collaborations with UCB Pharma (UCB) and F. Hoffmann-La Roche Ltd, respectively, to RPI Finance Trust (RPI), an affiliate of Royalty Pharma for $124.0 million.

•2020 Purchase and Sale Agreement: In December 2020, we sold our rights, subject to a cap, to receive royalties from MOVANTIK® / MOVENTIG® (for the treatment of opioid-induced constipation), ADYNOVATE® / ADYNOVI® (a half-life extension product of Factor VIII) and other hemophilia products, under our arrangements with

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AstraZeneca AB, Baxalta, Inc. (a wholly owned-subsidiary of Takeda Pharmaceutical Company Ltd.), and Novo Nordisk A/S, respectively, for $150.0 million to entities managed by Healthcare Royalty Management, LLC (HCR) under a capped sale arrangement, such that all future royalties return to Nektar if HCR receives $210.0 million in royalties by December 31, 2025 (the 2025 Threshold) or $240.0 million if the 2025 Threshold is not met. On March 4, 2024, Nektar and HCR amended the 2020 Purchase and Sale Agreement to remove the cap on the royalties in exchange for $15.0 million. See Note 3 to our Condensed Consolidated Financial Statements for additional information.

Our business is subject to significant risks, including the risks inherent in our development efforts, the results of our clinical trials, our dependence on the marketing efforts by our collaboration partners, uncertainties associated with obtaining and enforcing patents, the lengthy and expensive regulatory approval process and competition from other products. Drug research and development is an inherently uncertain process with a high risk of failure at every stage prior to approval. The timing and outcome of clinical trial results are extremely difficult to predict. Clinical development successes and failures can have a disproportionately positive or negative impact on our scientific and medical prospects, financial condition and prospects, results of operations and market opportunities. For a discussion of these and some of the other key risks and uncertainties affecting our business, see Item 1A “Risk Factors.”

With respect to financing our near-term business needs, as set forth below in “Key Developments and Trends in Liquidity and Capital Resources,” we estimate we have working capital to fund our current business plans through at least the next twelve months. At March 31, 2024, we had approximately $326.0 million in cash and investments in marketable securities.

Results of Operations

The following sets forth our Condensed Consolidated Statements of Operations data for each of the periods indicated (in thousands, except percentages).

	Three Months Ended March 31,						$ Change 2024 vs. 2023			% Change 2024 vs. 2023
	2024			2023
Revenue:
Product sales	$	6,034		$	4,718		$	1,316			28	%
Non-cash royalty revenue related to sales of future royalties		15,508			16,861			(1,353	)		(8	)%
License, collaboration and other revenue		97			15			82			547	%
Total revenue		21,639			21,594			45			0	%
Operating costs and expenses:
Cost of goods sold		8,534			7,060			1,474			21	%
Research and development		27,408			30,469			(3,061	)		(10	)%
General and administrative		20,149			21,081			(932	)		(4	)%
Restructuring, impairment and costs of terminated program		975			21,193			(20,218	)		(95	)%
Impairment of goodwill		—			76,501			(76,501	)		(100	)%
Total operating costs and expenses		57,066			156,304			(99,238	)		(63	)%
Loss from operations		(35,427	)		(134,710	)		99,283			(74	)%
Non-operating income (expense):
Non-cash interest expense on liability related to sale of future royalties		(5,531	)		(6,405	)		874			(14	)%
Interest income		4,220			4,335			(115	)		(3	)%
Other income (expense), net		(99	)		(301	)		202			(67	)%
Total non-operating income (expense), net		(1,410	)		(2,371	)		961			(41	)%
Loss before provision for income taxes		(36,837	)		(137,081	)		100,244			(73	)%
Provision (benefit) for income taxes		(35	)		(63	)		28			(44	)%
Net loss	$	(36,802	)	$	(137,018	)	$	100,216			(73	)%

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Revenue

Our revenue has historically been derived from our collaboration agreements, under which we may receive product sales revenue, royalties, and license fees, as well as development and sales milestones and other contingent payments. We recognize revenue when we transfer promised goods or services to our collaboration partners.

•Product sales and Cost of goods sold: Product sales include predominantly fixed price manufacturing and supply agreements with our collaboration partners and are the result of firm purchase orders from those partners. Accordingly, the revenue recognized in a given period is based solely on the demand and requirements of our collaboration partners and is not ratable throughout the year. We expect product sales to increase for 2024 as compared to 2023 due to increased demand from our partners with a corresponding increase in cost of goods sold.

We have a manufacturing arrangement with UCB that includes a fixed price which is less than the fully burdened manufacturing cost for the reagent, and we expect this situation to continue in future years. As a result of this arrangement, gross margin was negative for the periods presented.

For three months ended March 31, 2024 and 2023, we recorded provisions of $1.0 million and $0.7 million, respectively, for the net realizable value of our batches as an increase to cost of goods sold. Our manufacturing agreement with UCB provides for a fixed price which we had negotiated in exchange for a higher royalty rate. Accordingly, when evaluating the net realizable value of our inventory for UCB, we include the negotiated increase of the royalties in our analysis, and the aggregate revenue has historically been greater than our manufacturing cost. Due to the decreases in the royalty rates for 2024 and 2025 as a result of a settlement agreement with UCB, the aggregate revenue is expected to be less than our manufacturing cost, and therefore we recorded a provision for net realizable value. As of March 31, 2024, we have recorded the resulting provision of $2.4 million. We expect the provision to increase further in 2024 because the further decrease in the royalty rate for 2025 will further decrease the aggregate revenue and therefore decrease the net realizable value of the inventory.

•Non-cash royalty revenue and Non-cash interest expense: We recognize non-cash royalty revenue and non-cash interest expense resulting from royalties on several products for which we had previously sold our rights to receive royalties under the 2012 and 2020 Purchase and Sale Agreements. These non-cash revenues and expenses have no effect on our cash flows, and we do not consider them material to our operations.

On March 4, 2024, Nektar and HCR amended the 2020 Purchase and Sale Agreement to remove the cap on the royalties in exchange for a $15.0 million payment to Nektar. See Note 3 to our Condensed Consolidated Financial Statements for additional information.

We expect non-cash royalty revenue to decrease for full year 2024 as compared to 2023 due to the decrease in the royalty rate from UCB, and we expect non-cash interest expense to decrease as a result of the lower liability balance.

•License, collaboration and other revenue: License, collaboration and other revenue includes the recognition of upfront payments, milestone and other contingent payments received in connection with our license and collaboration agreements. The amount of revenue depends in part upon the estimated recognition period of the upfront payments allocated to continuing performance obligations, the achievement of milestones and other contingent events, the continuation of existing collaborations, the amount of research and development work, and entering into new collaboration agreements, if any. License, collaboration and other revenue was not material for the periods presented or for the full year 2023, and we do not expect to recognize significant revenue for the full year 2024.

Research and Development Expense

Research and development expense consists primarily of clinical study costs, contract manufacturing costs, direct costs of outside research, materials, supplies, licenses and fees as well as personnel costs (including salaries, benefits, and non-cash stock-based compensation). Research and development expense also includes certain overhead allocations consisting of support and facilities-related costs.

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Research and development expense decreased for the three months ended March 31, 2024 as compared to the three months ended March 31, 2023, primarily reflecting a decrease in employee costs and related facilities costs and a decrease in development expense for NKTR-255, partially offset by an increase in expense for the development of rezpegaldesleukin and NKTR-0165. However, we expect research and development expense in total to increase in 2024 as compared to 2023 primarily due to the increased expense for the development of rezpegaldesleukin in two Phase 2b trials. Additionally, beginning in the three months ended March 31, 2024, we began reporting, as research and development expense, the costs of winding down the bempegaldesleukin program, which was previously reported in restructuring, impairment and costs of terminated program, as the amounts are immaterial.

As discussed in Note 7 to our Condensed Consolidated Financial Statements, pursuant to our 2023 Restructuring Plan, we reduced our San Francisco-based workforce by approximately 60%, which was substantially completed by June 2023. Additionally, pursuant to the 2023 Restructuring Plan, we decided to sublease our remaining office and laboratory space on Mission Bay Blvd. South, and therefore we ceased recording a portion of the related lease expense as research and development expense after June 2023 upon completing the reduction in force. We expect employee costs and allocations of facilities-related costs to decrease for full year 2024 as compared to 2023 for these same reasons.

Research and development expense for rezpegaldesleukin increased for the three months ended March 31, 2024 as compared to the three months ended March 31, 2023, due to the initiation of the Phase 2b study in patients with moderate-to-severe atopic dermatitis in October 2023 and the Phase 2b study in patients with severe-to-very severe alopecia areata in March 2024. We expect the costs of development of rezpegaldesleukin to increase significantly for full year 2024 as compared to 2023 due to these Phase 2b studies.

Research and development expense for NKTR-255 decreased for the three months ended March 31, 2024 as compared to the three months ended March 31, 2023, as our development activities in 2024 are reduced compared to the prior period, and we expect development expense for full year 2024 to decrease as compared to 2023 for this same reason. Our development expense for NKTR-255 includes the Nektar-sponsored Phase 2 study to evaluate NKTR-255 following Yescarta® or Breyanzi® CD19 CAR-T cell therapy in patients with large B-cell lymphoma, the Fred Hutchinson Cancer Center investigator-sponsored study evaluating NKTR-255 following Breyanzi® CD19 CAR-T cell therapy in patients with relapsed/refractory large B-cell lymphoma, our oncology clinical collaboration with Merck KGaA to evaluate the maintenance regimen of NKTR-255 in combination with avelumab, a PD-L1 inhibitor, in patients with locally advanced or metastatic urothelial carcinoma in the Phase II JAVELIN Bladder Medley study, and an ongoing investigator sponsored study evaluating NKTR-255 in combination with IMFINZI (durvalumab) in patients with unresectable Stage 3 NSCLC who have received chemoradiation.

In December 2023, for our NKTR-0165 program, we exercised an option to gain an exclusive license to specified agonistic antibodies and other materials that were developed pursuant to a research collaboration and license option agreement we entered into with Biolojic Design, Ltd. in 2021. Research and development expense for NKTR-0165 increased for the three months ended March 31, 2024 as compared to the three months ended March 31, 2023, as we conduct IND enabling studies for this program in 2024, and we expect development expense for NKTR-0165 to increase for full year 2024 as compared to 2023 for the same reason.

The timing and amount of our future clinical trial expenses will vary significantly based upon our evaluation of ongoing clinical results and the structure, timing, and scope of additional clinical development programs and potential clinical collaboration partnerships (if any) for these programs.

In addition to our drug candidates that we plan to evaluate in clinical development during 2024 and beyond, we believe it is vitally important to continue our substantial investment in a pipeline of new drug candidates to continue to build the value of our drug candidate pipeline and our business. We continue our interest in identifying new drug candidates across a wide range of molecule classes, including small molecules and large proteins, peptides and antibodies, across multiple therapeutic areas. We also plan from time to time to evaluate opportunities to in-license potential drug candidates from third parties to add to our drug discovery and development pipeline. We plan to continue to advance our most promising early research drug candidates into preclinical development with the objective to advance these early stage research programs to human clinical studies over the next several years.

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Our expenditures on current and future preclinical and clinical development programs are subject to numerous uncertainties in timing and cost to completion. In order to advance our drug candidates through clinical development, each drug candidate must be tested in numerous preclinical safety, toxicology and efficacy studies. We then conduct clinical studies for our drug candidates that take several years to complete. The cost and time required to complete clinical trials may vary significantly over the life of a clinical development program as a result of a variety of factors, including but not limited to:

•the number of patients required for a given clinical study design;

•the length of time required to enroll clinical study participants;

•the number and location of sites included in the clinical studies;

•the clinical study designs required by the health authorities (i.e. primary and secondary endpoints as well as the size of the study population needed to demonstrate efficacy and safety outcomes);

•the potential for changing standards of care for the target patient population;

•the competition for patient recruitment from competitive drug candidates being studied in the same clinical setting;

•the costs of producing supplies of the drug candidates needed for clinical trials and regulatory submissions;

•the safety and efficacy profile of the drug candidate;

•the use of clinical research organizations to assist with the management of the trials; and

•the costs and timing of, and the ability to secure, approvals from government health authorities.

Furthermore, our strategy includes the potential of entering into collaborations with third parties to participate in the development and commercialization of some of our drug candidates, or clinical collaborations where we would share costs and operational responsibility with a partner. In certain situations, the clinical development program and process for a drug candidate and the estimated completion date will largely be under the control of that third party and not under our control. We cannot forecast with any degree of certainty which of our drug candidates will be subject to future collaborations or how such arrangements would affect our development plans or capital requirements.

General and Administrative Expense

General and administrative expense includes the cost of administrative staffing, finance and legal activities, including certain overhead allocations consisting of support and facilities-related costs. Additionally, general and administrative expense includes our lease and other facilities expenses for spaces we have sublet or are seeking to sublease, net of sublease income. General and administrative expense decreased slightly for the three months ended March 31, 2024, as compared to the three months ended March 31, 3023, reflecting a decrease in employee costs, partially offset by a reduction of facilities costs allocated to research and development expense. As discussed in Note 7 to our Condensed Consolidated Financial Statements, pursuant our 2023 Restructuring Plan, we reduced our San Francisco-based workforce by approximately 60%, which we substantially completed by June 2023. As discussed above, as a result of the reduction in force and our decision to seek a sublease for our remaining space in our Mission Bay Blvd. South facility, we ceased recording the related facilities expense as research and development expense after June 2023, resulting in an increase to general and administrative expense.

We expect general and administrative expense will decrease slightly for full year 2024 as compared to 2023.

Restructuring, Impairment and Costs of Terminated Program

As discussed in Note 7 to our Condensed Consolidated Financial Statements, we have incurred significant costs as a result of our 2022 and 2023 Restructuring Plans. In connection with these events, we reported the following costs in restructuring, impairment and costs of terminated program as further described and disclosed in Note 7 to our Condensed Consolidated Financial Statements (in thousands):

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	Three Months Ended March 31,
	2024		2023
Clinical trial expense, other third-party and employee costs for the wind down of the bempegaldesleukin program	$	—	$	1,598
Severance and benefit expense		—		5,483
Impairment of right-of-use assets and property, plant and equipment		—		13,200
Contract termination and other restructuring costs		975		912
Restructuring, impairment and other costs of terminated program	$	975	$	21,193

•Clinical trial expense, other third-party and employee costs for the wind down of the bempegaldesleukin program: We recognized $5.5 million for the full year of 2023 for the wind down of the bempegaldesleukin program. Because the amounts have become immaterial, we report these costs within research and development expense for 2024.

•Severance and benefits expense: We recognized $7.9 million for severance and benefit expense in 2023 for the 2023 Restructuring Plan. We do not expect to recognize expense for the 2023 Restructuring Plan in 2024.

•Impairment of right-of-use assets and property, plant and equipment: We recognized $35.3 million in non-cash impairment charges for the full year 2023, primarily for office and laboratory space on Mission Bay Blvd. South and our office space on Third St., reflecting deteriorations in both the laboratory and office lease markets. While we continue to seek subleases for our remaining spaces, we will continue to update our estimates based on changes in market conditions, whether or not we are able to enter into subleases and, if we do enter into subleases, the economic terms of those subleases, and we may record non-cash impairment charges in future periods as these estimates change.

•Contract termination and other restructuring charges: We recognized $2.0 million in contract termination and other restructuring costs for the full year 2023, primarily resulting from our 2022 Restructuring Plan. We will continue to recognize expense as our estimates change until final settlement.

Impairment of Goodwill

As discussed in Note 8 to our Condensed Consolidated Financial Statements, during the three months ended March 31, 2023, our stock price and resulting market capitalization experienced a significant, sustained decline. As a result, we measured the fair value of the Company based on income and market approaches. Based on this analysis, we wrote off all of our goodwill in the three months ended March 31, 2023. We had previously recognized goodwill primarily from our acquisitions of Shearwater Corp. and Aerogen, Inc. in 2001 and 2005, respectively.

Interest Income

Interest income was consistent for the periods presented, reflecting an increase in interest rates offset by a decrease in our investment balances. We expected interest income to decrease for 2024 due to lower investment balances as we fund our operations.

Liquidity and Capital Resources

We have financed our operations primarily through revenue from upfront and milestone payments under our strategic collaboration agreements, royalties and product sales, as well as public and private placements of debt and equity securities. As of March 31, 2024, we had approximately $326.0 million in cash and investments in marketable securities. During the three months ended March 31, 2024, we entered into the following transactions:

•On February 12, 2024, for total cash consideration paid of $3.0 million, we repurchased the 8.3 million shares previously sold to BMS. See Note 6 to our Condensed Consolidated Financial Statements for additional information.

•On March 4, 2024, we entered into a Securities Purchase Agreement with TCG Crossover Fund II, L.P., pursuant to which we issued a pre-funded warrant to TCG to purchase an aggregate 25,000,000 shares of Nektar’s common stock

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at a price of $1.20 per share for gross proceeds of $30.0 million. See Note 5 to our Condensed Consolidated Financial Statements for additional information.

•On March 4, 2024, for total cash consideration received of $15.0 million, Nektar entered into an amendment with HCR to remove the cap under the 2020 Purchase and Sale Agreement. See Note 3 to our Condensed Consolidated Financial Statements for additional information.

We estimate that we have working capital to fund our current business plans for at least the next twelve months from the date of filing.

We expect the clinical development of our drug candidates, including rezpegaldesleukin and NKTR-255, will continue to require significant investment to continue to advance in clinical development with the objective of obtaining regulatory approval or entering into one or more collaboration partnerships. In the past, we have received a number of significant payments from collaboration agreements and other significant transactions, including $1.9 billion in total consideration received under our arrangement with BMS, development cost reimbursements from BMS, and a $150.0 million upfront payment from Lilly for our collaboration agreement for rezpegaldesleukin. Additionally, certain of our collaboration partners have borne substantial costs of developing our drug candidates. Following the return of our rights to develop rezpegaldesleukin from Lilly, however, unless we enter into a new collaboration agreement, we bear all the costs of developing our pipeline drug candidates, other than our collaborations for NKTR-255 described above.

Our current business is subject to significant uncertainties and risks as a result of, among other factors, clinical and regulatory outcomes for rezpegaldesleukin and NKTR-255; the sales levels for those products, if and when they are approved; whether, when and on what terms we are able to enter into new collaboration transactions; expenses being higher than anticipated, unplanned expenses and the need to satisfy contingent liabilities, including litigation matters and indemnification obligations; and cash receipts, including sublease income, being lower than anticipated.

We have no credit facility or any other sources of committed capital. The availability and terms of various financing alternatives, if required in the future, substantially depend on many factors including the success or failure of drug development programs in our pipeline. The availability and terms of financing alternatives and any future significant payments from existing or new collaborations depend on the positive outcome of ongoing or planned clinical studies, whether we or our partners are successful in obtaining regulatory authority approvals in major markets, and if approved, the commercial success of these drugs, as well as general capital market conditions. We may pursue various financing alternatives to fund the expansion of our business as appropriate.

As a result of our 2022 and 2023 Restructuring Plans, we are seeking to sublease all of our laboratory and office space on Mission Bay Blvd. South and our office space on Third St., and we have current subleases for a portion of our laboratory and office spaces on Mission Bay Blvd. South. The San Francisco Bay Area office lease market has been negatively impacted by economic uncertainties, particularly impacting the technology industry, and the change in work habits following the COVID-19 pandemic, as employees continue to work remotely. Accordingly, for our vacant office space on Third St., there is significant uncertainty as to whether or when we will be able to enter into a sublease as well as the economic terms of such subleases, if any. While the San Francisco Bay Area life sciences lease market remained strong during 2022, it has weakened during 2023 and 2024, including a significant increase in available leasable space in the San Francisco Bay Area. Accordingly, there is increased uncertainty as to whether or when we will be able to enter into a sublease as well as the economic terms of such subleases, if any.

Due to the potential for adverse developments in the credit markets, we may experience reduced liquidity with respect to some of our investments in marketable securities. These investments are generally held to maturity, which, in accordance with our investment policy, is less than two years. However, if the need arises to liquidate such securities before maturity, we may experience losses on liquidation. To date we have not experienced any liquidity issues with respect to these securities. We believe that, even allowing for potential liquidity issues with respect to these securities and the effect of various conditions on the financial markets, our remaining cash and investments in marketable securities will be sufficient to meet our anticipated cash needs for at least the next twelve months.

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Cash flows from operating activities

Cash flows used in operating activities for the three months ended March 31, 2024 and 2023 totaled $47.9 million and $51.9 million, respectively.

We expect that cash flows used in operating activities, excluding upfront, milestone and other contingent payments received, if any, will increase for 2024 as compared to 2023 due to the development of rezpegaldesleukin in the Phase 2b trials discussed above.

Cash flows from investing activities

During the three months ended March 31, 2024 and 2023, the maturities and sales of our investments, net of purchases, totaled $19.4 million and $41.0 million, respectively, which we used to fund our operations. Our other investing activities were not significant for the periods presented.

Cash flows from financing activities

Other than the three financing activities described above during the three months ended March 31, 2024, our cash flows from financing activities for the three months ended March 31, 2024 and 2023 were not significant.

Critical Accounting Policies and Estimates

The preparation and presentation of financial statements in conformity with U.S. generally accepted accounting principles (GAAP) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period.

We base our estimates on historical experience and on various other assumptions that we believe to be reasonable under the circumstances, the results of which form our basis for making judgments about the carrying value of assets and liabilities that are not readily apparent from other sources. We evaluate our estimates on an ongoing basis. Actual results may differ from those estimates under different assumptions or conditions.

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Item 3. Quantitative and Qualitative Disclosures about Market Risk

Our market risks at March 31, 2024 have not changed materially from those discussed in Item 7A of our Annual Report on Form 10-K for the year ended December 31, 2023 on file with the SEC.

Item 4. Controls and Procedures

Disclosure Controls and Procedures

We maintain disclosure controls and procedures that are designed to ensure that information required to be disclosed in our Securities Exchange Act of 1934 (Exchange Act) reports is recorded, processed, summarized, and reported within the time periods specified in the rules and forms of the SEC, and that such information is accumulated and communicated to management, including our Chief Executive Officer and Chief Financial Officer, as appropriate, to allow timely decisions regarding required disclosure.

As of the end of the period covered by this report, we carried out an evaluation, under the supervision and with the participation of our management, including our Chief Executive Officer and Chief Financial Officer, of the effectiveness of the design and operation of our disclosure controls and procedures pursuant to Exchange Act Rule 13a-15. Based upon, and as of the date of, this evaluation, our Chief Executive Officer and Chief Financial Officer concluded that our disclosure controls and procedures were effective.

Changes in Internal Control Over Financial Reporting

We continuously seek to improve the efficiency and effectiveness of our internal controls. This results in refinements to processes throughout the Company. However, there was no change in our internal control over financial reporting that occurred in the three months ended March 31, 2024 that has materially affected, or is reasonably likely to materially affect, our internal control over financial reporting.

Limitations on the Effectiveness of Controls

Our management, including our Chief Executive Officer and Chief Financial Officer, does not expect that our disclosure controls and procedures or our internal control over financial reporting will prevent all error and all fraud. A control system, no matter how well conceived and operated, can provide only reasonable, not absolute, assurance that the objectives of the control system are met. Because of the inherent limitations in all control systems, no evaluation of controls can provide absolute assurance that all control issues and instances of fraud, if any, within the company have been detected. These inherent limitations include the realities that judgments in decision-making can be faulty, and that breakdowns can occur because of simple errors or mistakes. Additionally, controls can be circumvented by the individual acts of some persons, by collusion of two or more people or by management override of the control. The design of any system of controls also is based in part upon certain assumptions about the likelihood of future events, and there can be no assurance that any design will succeed in achieving its stated goals under all potential future conditions. Over time, controls may become inadequate because of changes in conditions, or the degree of compliance with the policies or procedures may deteriorate. Because of the inherent limitations in a cost-effective control system, misstatements due to error or fraud may occur and not be detected.

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PART II: OTHER INFORMATION

Item 1. Legal Proceedings

Reference is hereby made to our disclosures in “Legal Matters” under Note 4 to our Condensed Consolidated Financial Statements in this Quarterly Report on Form 10-Q and the information under the heading “Legal Matters” is incorporated by reference herein.

Item 1A. Risk Factors

We are providing the following cautionary discussion of risk factors, uncertainties and assumptions that we believe are relevant to our business. These are factors that, individually or in the aggregate, we think could cause our actual results to differ materially from expected and historical results and our forward-looking statements. We note these factors for investors as permitted by Section 21E of the Exchange Act and Section 27A of the Securities Act.

Investors in Nektar Therapeutics should carefully consider the risks described below before making an investment decision. You should understand that it is not possible to predict or identify all such factors. Consequently, you should not consider this section to be a complete discussion of all potential risks or uncertainties that may substantially impact our business. Moreover, we operate in a competitive and rapidly changing environment. New factors emerge from time to time and it is not possible to predict the impact of all of these factors on our business, financial condition or results of operations. The risks described below may not be the only ones relating to our company. This description includes any material changes to and supersedes the description of the risk factors associated with our business previously disclosed in Item 1A of our Annual Report on Form 10-K for the year ended December 31, 2023.

Risks Related to our Business

We are highly dependent on the success of drug candidates, including rezpegaldesleukin (previously referred to as NKTR-358) and NKTR-255. If these drug candidates fail in clinical development our business will be significantly harmed.

Our future success is highly dependent on the clinical success of our drug candidates, including rezpegaldesleukin and NKTR-255. In general, most investigational drugs, including drug candidates designed to treat patients suffering from autoimmune disorders and cancers, such as rezpegaldesleukin and NKTR-255, respectively, do not become approved drugs. Accordingly, there is a very meaningful risk that our drug candidates will not succeed in one or more clinical trials sufficient to support one or more regulatory approvals.

We previously relied on Lilly (through the Lilly Agreement) to initiate, properly conduct, and prioritize clinical trials and other development-related activities for rezpegaldesleukin. In February 2023, we announced that the Phase 2 Lupus Study of rezpegaldesleukin in systemic lupus erythematosus (SLE) conducted by Lilly did not meet the study’s primary endpoint and that Lilly does not intend to advance rezpegaldesleukin to Phase 3 development in SLE. On April 27, 2023, we announced that we would be regaining the full rights to rezpegaldesleukin from Lilly, and the collaboration agreement subsequently terminated. Following the return of our rights to develop rezpegaldesleukin, we bear all costs of development. We have initiated two Phase 2b rezpegaldesleukin studies: one in patients with moderate-to-severe atopic dermatitis, and another in patients with severe-to-very severe alopecia areata. We will also explore other auto-immune indications for the development of rezpegaldesleukin. While we believe we currently have the materials that are necessary for us to continue clinical development of rezpegaldesleukin, we may need or benefit from additional materials that Lilly has not yet transferred to us. In the event Lilly fails to promptly and completely transfer to us any additional needed materials or we are not able to independently source these materials, the continued clinical development of rezpegaldesleukin and our business will be significantly harmed. Even if the applicable agreement provides us with enforcement or other curative rights to address the harm caused by Lilly’s action (or failure to act), our efforts in pursuing a remedy would be costly and there is no guarantee that these efforts would succeed or be sufficient to fully address the harm. If continued development of rezpegaldesleukin is not ultimately successful, our market valuation, prospects, financial condition and results of operations would be materially harmed.

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Additionally, promising results from earlier trials may not predict similarly favorable outcomes in subsequent trials. For example, several of our past, planned and ongoing clinical trials utilize an “open-label” trial design. An “open-label” clinical trial is one where both the patient and investigator know whether the patient is receiving the investigational drug candidate or either an existing approved drug or placebo. Most typically, open-label clinical trials test only the investigational drug candidate and sometimes may do so at different dose levels. Open-label clinical trials are subject to various limitations that may exaggerate any therapeutic effect as patients in open-label clinical trials are aware when they are receiving treatment. Open-label clinical trials may be subject to a “patient bias” where patients perceive their symptoms to have improved merely due to their awareness of receiving an experimental treatment. In addition, open-label clinical trials may be subject to an “investigator bias” where those assessing and reviewing the physiological outcomes of the clinical trials are aware of which patients have received treatment and may interpret the information of the treated group more favorably given this knowledge. The results from an open-label trial may not be predictive of future clinical trial results with any of our drug candidates for which we include an open-label clinical trial when studied in a controlled environment with a placebo or active control. One or more clinical failures of our drug candidates would jeopardize and could materially harm our business, results of operations and financial condition.

Delays in clinical studies are common and have many causes, and any significant delay in clinical studies being conducted by us or our partners could result in delay in regulatory approvals and jeopardize the ability to proceed to commercialization.

We or our partners may experience delays in conducting clinical trials of our drug candidates. Clinical studies may not begin on time, enroll a sufficient number of patients or be completed on schedule, if at all. Clinical trials for any of our drug candidates could be delayed for a variety of reasons, including:

•delays in obtaining regulatory authorization to commence a clinical study;

•delays in reaching agreement with applicable regulatory authorities on a clinical study design;

•for drug candidates currently or previously partnered with other companies, delays caused by our partner;

•delays caused by the COVID-19 pandemic (see also the risk factor in this Item 1A titled “Our business could be adversely affected by the effects of health epidemics, including the recent COVID-19 pandemic”).

•imposition of a clinical hold by the FDA or other health authorities, which may occur at any time including after any inspection of clinical trial operations or trial sites;

•suspension or termination of a clinical study by us, our partners, the FDA or foreign regulatory authorities due to adverse side effects of a drug on subjects in the trial;

•delays in recruiting suitable patients to participate in a trial;

•delays in having patients complete participation in a trial or return for post-treatment follow-up;

•clinical sites dropping out of a trial due to the detriment of enrollment rates;

•delays in manufacturing and delivery of sufficient supply of clinical trial materials;

•changes in regulatory authorities policies or guidance applicable to our drug candidates;

•delays caused by changing standards of care or new treatment options; and

•delays associated with third parties, such as a past collaboration partner, failing to provide us with all the necessary documents, data and materials necessary to conduct clinical trials.

If the initiation or completion of any of the planned clinical studies for our drug candidates is delayed for any of the above or other reasons, results for the studies would be delayed, and consequently the regulatory approval process would be delayed which would also delay the ability to commercialize these drug candidates, which could have a material adverse effect on our business, financial condition and results of operations. Clinical study delays could also shorten any commercial periods during

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which our products have patent protection and may allow our competitors to bring products to market before we do, which could impair our ability to successfully commercialize our drug candidates and may harm our business and results of operations.

We currently rely on academic and private non-academic institutions to conduct investigator-sponsored clinical studies or trials of our product candidates. Any failure by the investigator-sponsor to meet its obligations with respect to the clinical development of our product candidates may delay or impair our ability to obtain regulatory approval or commercialize for other product candidates.

We currently rely on academic and private non-academic institutions to conduct and sponsor clinical studies or trials relating to our product candidates. We do not control the design or conduct of the investigator-sponsored trials, and it is possible that the FDA or non-U.S. regulatory authorities will not view these investigator-sponsored studies or trials as providing adequate support for future clinical trials, whether controlled by us or independent investigators, for any one or more reasons, including elements of the design or execution of the trials or safety concerns or other trial results.

Such arrangements will likely provide us certain information concerning our drug candidates with respect to the investigator-sponsored studies or trials, including access to and the ability to use and reference the data, including for our own regulatory filings, resulting from the investigator-sponsored studies or trials. However, we would not have control over the timing and reporting of the data from investigator-sponsored trials, nor would we own the data from the investigator-sponsored studies or trials. If we are unable to confirm or replicate the results from the investigator-sponsored studies or trials or if negative results are obtained, we would likely be further delayed or prevented from advancing further clinical development of our product candidates. Further, if investigators or institutions breach their obligations with respect to the clinical development of our product candidates, or if the data proves to be inadequate compared to the first-hand knowledge we might have gained had the investigator-sponsored studies or trials been sponsored and conducted by us, then our ability to design and conduct any future clinical trials ourselves may be adversely affected.

Additionally, the FDA or non-U.S. regulatory authorities may disagree with the sufficiency of our right of reference to the preclinical, manufacturing or clinical data generated by these investigator-sponsored studies or trials or our interpretation of preclinical, manufacturing or clinical data from these investigator-sponsored studies or trials. If so, the FDA or other non-U.S. regulatory authorities may require us to obtain and submit additional preclinical, manufacturing or clinical data before we may initiate our planned clinical trials and/or may not accept such additional data as adequate to initiate our planned clinical trials.

The outcomes from the clinical trials of drug candidates from others, and the discovery and development of new potential therapies in immunology and oncology, could have a material and adverse impact on the value of the drug candidates in our research and development pipeline.

The research and development of immune-modulatory agents is a very competitive global segment in the biopharmaceutical industry attracting tens of billions of dollars of investment each year. Our clinical trial plans for rezpegaldesleukin, NKTR-255 and other drug candidates face substantial competition from other regimens already approved, and many more that are either ahead of or in parallel development in patient populations where we are studying our drug candidates. As immunotherapy represents a relatively new approach to treatment of autoimmune disorders and cancer and few have successfully completed late stage development, drug development in this area entails substantial risks and uncertainties that include rapidly changing standards of care, identifying contribution of components when therapeutic combinations are employed, patient enrollment competition, evolving regulatory frameworks to evaluate regimens, and varying risk-benefit profiles of competing therapies, any or all of which could have a material and adverse impact on the probability of success of our drug candidates.

The risk of clinical failure for any drug candidate remains high prior to regulatory approval and there can be no assurance that our product candidates will obtain regulatory approval for any particular indications.

A number of companies have suffered significant unforeseen failures in clinical studies due to factors such as inconclusive efficacy or safety, even after achieving preclinical proof-of-concept or positive results from earlier clinical studies

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that were satisfactory both to them and to reviewing regulatory authorities. Clinical study outcomes remain very unpredictable and it is possible that one or more of our clinical studies could fail at any time due to efficacy, safety or other important clinical findings or regulatory requirements. The results from preclinical testing or early clinical trials of a drug candidate may not predict the results that will be obtained in later phase clinical trials of the drug candidate. We, the FDA, an independent Institutional Review Board (IRB), an independent ethics committee (IEC), or other applicable regulatory authorities may suspend clinical trials of a drug candidate at any time for various reasons, including a belief that patients participating in such trials are being exposed to unacceptable health risks or adverse side effects. Similarly, an IRB or IEC may suspend a clinical trial at a particular trial site. If one or more of our drug candidates fail in clinical studies, it could have a material adverse effect on our business, financial condition and results of operations.

Significant competition for our polymer conjugate chemistry technology platforms and our partnered and proprietary drugs and drug candidates could make our technologies, drugs or drug candidates obsolete or noncompetitive, which would negatively impact our business, results of operations and financial condition.

Our advanced polymer conjugate chemistry platforms and our partnered and proprietary products and drug candidates compete with various pharmaceutical and biotechnology companies. Competitors of our polymer conjugate chemistry technologies include Biogen Inc., Horizon Pharma, Dr. Reddy’s Laboratories Ltd., SunBio Corporation, Laysan Bio, Inc., Mountain View Pharmaceuticals, Inc., Novo Nordisk A/S (formerly assets held by Neose Technologies, Inc.), NOF Corporation and Aurigene Pharmaceutical Services. Several other chemical, biotechnology and pharmaceutical companies may also be developing polymer conjugation technologies or technologies that have similar impact on target drug molecules. Some of these companies license or provide the technology to other companies, while others are developing the technology for internal use.

There are many competitors for our drug candidates currently in development. For rezpegaldesleukin, there are a number of competitors in various stages of clinical development that are working on programs which are designed to correct the underlying immune system imbalance in the body due to autoimmune disease. In particular, we expect to compete with therapies that could be cytokine-based, microbiome-based, or toleragenic-based therapies (Symbiotix, LLC, Janssen, AstraZeneca, and Tizona Therapeutics), regulatory T cell therapies (Sangamo Therapeutics, Inc., Quell Therapeutics, Ltd, TxCell, Inc., Sonoma Biotherapeutics, Inc., GentiBio, Inc. Kyvema Therapeutics, Inc. and and Tract Therapeutics, Inc.), or IL-2-based-therapies (Amgen Inc., BMS, Novartis, Inc., ILTOO Pharma, Xencor, Inc. Merck & Co, through its acquisition of Pandion Therapeutics, and Sanofi SA, through its acquisition of Synthorx, Inc.). For NKTR-255, we believe companies that are currently researching and developing engineered IL-15 biologics and cell therapies that could compete with this drug candidate include Artiva Biotherapeutics, Fate Therapeutics, ImmunityBio, Inc., Nkarta Therapeutics, NKMax America, and Roche/Genentech (through its partnership with Xencor, Inc.). There can be no assurance that we or our partners will successfully develop, obtain regulatory approvals for and commercialize next-generation or new products that will successfully compete with those of our competitors. Many of our competitors have greater financial, research and development, marketing and sales, manufacturing and managerial capabilities. We face competition from these companies not just in product development but also in areas such as recruiting employees, acquiring technologies that might enhance our ability to commercialize products, establishing relationships with certain research and academic institutions, enrolling patients in clinical trials and seeking program partnerships and collaborations with larger pharmaceutical companies. As a result, our competitors may succeed in developing competing technologies, obtaining regulatory approval or gaining market acceptance for products before we do. These developments could make our products or technologies noncompetitive or obsolete.

Preliminary and interim data from our clinical studies that we announce or publish from time to time are subject to audit and verification procedures that could result in material changes in the final data and may change as more patient data become available.

From time to time, we publish preliminary or interim data from our clinical studies. Preliminary data remain subject to audit confirmation and verification procedures that may result in the final data being materially different from the preliminary data we previously published. Interim data are also subject to the risk that one or more of the clinical outcomes may materially change as patient enrollment continues and more patient data become available. As a result, preliminary and interim data should be

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viewed with caution until the final data are available. Material adverse changes in the final data could significantly harm our business prospects.

Risks Related to our Financial Condition and Capital Requirement

Additional cost-savings measures may be necessary following implementation of our strategic reorganization plan and cost restructuring plans.

Our 2022 and 2023 Restructuring Plans prioritized key research and development efforts that will impact the Company’s future business activities, including activities involving rezpegaldesleukin, NKTR-255 and several core research programs. There is no guarantee that these Restructuring Plans and their associated cost restructuring measures will achieve their intended benefits or that our post-restructuring focus will be sufficient for us to achieve success. Consequently, we may need to undertake additional restructuring and cost-saving activities to further prioritize our key research and development efforts and these additional restructuring and cost-saving activities may not be successful, which could have a material adverse effect on our business, financial condition and prospects.

Our results of operations and financial condition depend significantly on the ability of our collaboration partners to successfully develop and market drugs and they may fail to do so.

Under our collaboration agreements with various pharmaceutical or biotechnology companies, our collaboration partner is generally solely responsible for:

•designing and conducting large scale clinical studies;

•preparing and filing documents necessary to obtain government approvals to sell a given drug candidate; and/or

•marketing and selling the drugs when and if they are approved.

Our reliance on collaboration partners poses a number of significant risks to our business, including risks that:

•we have very little control over the timing and level of resources that our collaboration partners dedicate to commercial marketing efforts such as the amount of investment in sales and marketing personnel, general marketing campaigns, direct-to-consumer advertising, product sampling, pricing agreements and rebate strategies with government and private payers, manufacturing and supply of drug product, and other marketing and selling activities that need to be undertaken and well executed for a drug to have the potential to achieve commercial success;

•collaboration partners with commercial rights may choose to devote fewer resources to the development or marketing of our partnered drugs than they devote to their own drugs or other drugs that they have in-licensed;

•we have very little control over the timing and amount of resources our partners devote to development programs in one or more major markets;

•disagreements with partners could lead to delays in, or termination of, the research, development or commercialization of drug candidates or to litigation or arbitration proceedings;

•disputes may arise or escalate in the future with respect to the ownership of rights to technology or intellectual property developed with partners;

•we do not have the ability to unilaterally terminate agreements (or partners may have extension or renewal rights) that we believe are not on commercially reasonable terms or consistent with our current business strategy;

•partners may be unable to pay us as expected;

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•partners may terminate their agreements with us unilaterally for any or no reason, in some cases with the payment of a termination fee penalty and in other cases with no termination fee penalty; and

•partners may respond to natural disasters or health epidemics by ceasing all or some of their development responsibilities (including the responsibility to clinical develop our drug candidates).

Given these risks, the success of our current and future collaboration partnerships is highly unpredictable and can have a substantial negative impact on our business. If the approved drugs fail to achieve commercial success or the drugs in development fail to have positive late stage clinical outcomes sufficient to support regulatory approval in major markets, it could significantly impair our access to capital necessary to fund our research and development efforts for our drug candidates. If we are unable to obtain sufficient capital resources to advance our drug candidate pipeline, it would negatively impact the value of our business, results of operations and financial condition.

We have substantial future capital requirements and there is a risk that we may not have access to sufficient capital to meet our current business plan. If we do not receive substantial milestone or royalty payments from our existing collaboration agreements, execute new high value collaborations or other arrangements, or are unable to raise additional capital in one or more financing transactions, we would be unable to continue our current level of investment in research and development.

As of March 31, 2024, we had cash and investments in marketable securities valued at approximately $326.0 million. While we believe that our cash position will be sufficient to meet our liquidity requirements through at least the next 12 months, our future capital requirements will depend upon numerous unpredictable factors, including:

•the cost, timing and outcomes of clinical studies and regulatory reviews of our drug candidates, particularly rezpegaldesleukin;

•if and when we receive potential milestone payments and royalties from our existing collaborations if the drug candidates subject to those collaborations achieve clinical, regulatory or commercial success;

•the progress, timing, cost and results of our clinical development programs;

•the success, progress, timing and costs of our efforts to implement new collaborations, licenses and other transactions that increase our current net cash, such as the sale of additional royalty interests held by us, term loan or other debt arrangements, and the issuance of securities;

•the number of patients, enrollment criteria, primary and secondary endpoints, and the number of clinical studies required by the regulatory authorities in order to consider for approval our drug candidates and those of our collaboration partners;

•our general and administrative expenses, capital expenditures and other uses of cash; and

•disputes concerning patents, proprietary rights, or license and collaboration agreements that could negatively impact our receipt of milestone payments or royalties or require us to make significant payments arising from licenses, settlements, adverse judgments or ongoing royalties.

A significant multi-year capital commitment is required to advance our drug candidates through the various stages of research and development in order to generate sufficient data to enable high value collaboration partnerships with significant upfront payments or to successfully achieve regulatory approval. In the event we do not enter into any new collaboration partnerships with significant upfront payments and we choose to continue to advance our drug candidates to later stage research and development, we may need to pursue financing alternatives, including dilutive equity-based financings, such as an offering of convertible debt or common stock, which would dilute the percentage ownership of our current common stockholders and could significantly lower the market value of our common stock. If sufficient capital is not available to us or is not available on commercially reasonable terms, it could require us to delay or reduce one or more of our research and development programs. If

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we are unable to sufficiently advance our research and development programs, it could substantially impair the value of such programs and result in a material adverse effect on our business, financial condition and results of operations.

The commercial potential of a drug candidate in development is difficult to predict. If the market size for a new drug is significantly smaller than we anticipate, it could significantly and negatively impact our revenue, results of operations and financial condition.

It is very difficult to estimate the commercial potential of drug candidates due to important factors such as safety and efficacy compared to other available treatments, including changing standards of care, third party payer reimbursement standards, patient and physician preferences, the availability of competitive alternatives that may emerge either during the long drug development process or after commercial introduction, and the availability of generic and biosimilar versions of our drug candidates following approval by regulatory authorities based on the expiration of regulatory exclusivity or our inability to prevent generic versions from coming to market by asserting our patents. If due to one or more of these risks the market potential for a drug candidate is lower than we anticipated, it could significantly and negatively impact the commercial potential of the drug candidate, the commercial terms of any collaboration partnership potential for such drug candidate, or if we have already entered into a collaboration for such drug candidate, the revenue potential from royalty and milestone payments could be significantly diminished and this would negatively impact our business, financial condition and results of operations. We may also depend on our relationships with other companies for sales and marketing performance and the commercialization of drug candidates. Poor performance by these companies, or disputes with these companies, could negatively impact our revenue and financial condition.

If government and private insurance programs do not provide payment or reimbursement for our partnered drug or proprietary drugs, those drugs will not be widely accepted, which would have a negative impact on our business, results of operations and financial condition.

In the United States and markets in other countries, patients generally rely on third-party payers to reimburse all or part of the costs associated with their treatment. In both domestic and foreign markets, sales of our partnered and proprietary products that receive regulatory approval will depend in part on market acceptance among physicians and patients, pricing approvals by government authorities and the availability of coverage and payment or reimbursement from third-party payers, such as government programs, including Medicare and Medicaid in the U.S., managed care providers, private health insurers and other organizations. However, eligibility for coverage does not necessarily signify that a biologic candidate will be adequately reimbursed in all cases or at a rate that covers costs related to research, development, manufacture, sale, and distribution. Third-party payers are increasingly challenging the price and cost effectiveness of medical products and services. Therefore, significant uncertainty exists as to the coverage and pricing approvals for, and the payment or reimbursement status of, newly approved healthcare products. For more information, see “Business – Government Regulation – Coverage, Reimbursement, and Pricing.”

There is also significant uncertainty related to the insurance coverage and reimbursement of newly approved products and coverage may be more limited than the purposes for which the medicine is approved by the FDA or comparable foreign regulatory authorities. In the United States, the principal decisions about reimbursement for new medicines are typically made by the Centers for Medicare & Medicaid Services, or CMS, an agency within the U.S. Department of Health and Human Services. CMS decides whether and to what extent a new medicine will be covered and reimbursed under Medicare and private payers tend to follow CMS to a substantial degree.

Factors payers consider in determining reimbursement are based on whether the product is (i) a covered benefit under its health plan; (ii) safe, effective and medically necessary; (iii) appropriate for the specific patient; (iv) cost-effective; and (v) neither experimental nor investigational.

In addition, net prices for drugs may be reduced by mandatory discounts or rebates required by government healthcare programs or private payers and by any future relaxation of laws that presently restrict imports of drugs from countries where they may be sold at lower prices than in the United States.

Increasingly, third-party payers are requiring that drug companies provide them with predetermined discounts from list prices and are challenging the prices charged for medical products. We cannot be sure that reimbursement will be available for any of our drug product candidates that are commercialized and, if reimbursement is available, the level of reimbursement.

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In addition, many pharmaceutical manufacturers must calculate and report certain price reporting metrics to the government, such as average sales price, or ASP, and best price. Penalties may apply in some cases when such metrics are not submitted accurately and timely. Further, these prices for drugs may be reduced by mandatory discounts or rebates required by government healthcare programs.

Moreover, legislation and regulations affecting the pricing of pharmaceuticals may change before regulatory agencies approve our proposed products for marketing and could further limit coverage or pricing approvals for, and reimbursement of, our products from government authorities and third-party payers. Federal agencies, Congress and state legislatures have continued to show interest in implementing cost containment programs to limit the growth of health care costs, including price controls, restrictions on reimbursement and other fundamental changes to the healthcare delivery system. In addition, in recent years, Congress has enacted various laws seeking to reduce the federal debt level and contain healthcare expenditures, and the Medicare and other healthcare programs are frequently identified as potential targets for spending cuts. New government legislation or regulations related to pricing or other fundamental changes to the healthcare delivery system as well as a government or third-party payer decision not to approve pricing for, or provide adequate coverage or reimbursement of, our products hold the potential to severely limit market opportunities of such products.

In addition, in some foreign countries, the proposed pricing for a drug must be approved before it may be lawfully marketed. The requirements governing drug pricing vary widely from country to country. For example, the European Union provides options for its Member States to restrict the range of medicinal products for which their national health insurance systems provide reimbursement and to control the prices of medicinal products for human use. To obtain reimbursement or pricing approval, some of these countries may require the completion of clinical trials that compare the cost effectiveness of a particular product candidate to currently available therapies. A Member State may approve a specific price for the medicinal product or it may instead adopt a system of direct or indirect controls on the profitability of the company placing the medicinal product on the market. There can be no assurance that any country that has price controls or reimbursement limitations for pharmaceutical products will allow favorable reimbursement and pricing arrangements for any of our product candidates. Historically, products launched in the European Union do not follow price structures of the U.S. and generally prices tend to be significantly lower.

If we are unable to establish and maintain collaboration partnerships on attractive commercial terms, our business, results of operations and financial condition could suffer.

We intend to continue to seek partnerships with pharmaceutical and biotechnology partners to fund a portion of our research and development capital requirements. The timing of new collaboration partnerships is difficult to predict due to availability of clinical data, the outcomes from our clinical studies, the number of potential partners that need to complete due diligence and approval processes, the definitive agreement negotiation process and numerous other unpredictable factors that can delay, impede or prevent significant transactions. If we are unable to find suitable partners or negotiate collaboration arrangements with favorable commercial terms with respect to our existing and future biologic candidates or the licensing of our intellectual property, or if any arrangements we negotiate, or have negotiated, are terminated, it could have a material adverse effect on our business, financial condition and results of operations.

Our revenue has historically been exclusively derived from our collaboration agreements, which can result in significant fluctuation in our revenue from period to period, and our past revenue is therefore not necessarily indicative of our future revenue.

Our revenue has historically been exclusively derived from our collaboration agreements (whether based on our drug candidates or polymeric reagents), from which we receive upfront fees, research and development reimbursement and funding, milestone and other contingent payments based on clinical progress, regulatory progress or net sales achievements, royalties and product sales. Significant variations in the timing of receipt of cash payments and our recognition of revenue can result from payments based on the execution of new collaboration agreements, the timing of clinical outcomes, regulatory approval, commercial launch or the achievement of certain annual sales thresholds. The amount of our revenue derived from collaboration agreements in any given period will depend on a number of unpredictable factors, including whether and when we or our

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collaboration partners achieve clinical, regulatory and sales milestones, the timing of regulatory approvals in one or more major markets, reimbursement levels by private and government payers, and the market introduction of new drugs or generic versions of the approved drug, as well as other factors. Our past revenue generated from collaboration agreements is not necessarily indicative of our future revenue. If any of our existing or future collaboration partners fails to develop, obtain regulatory approval for, manufacture or ultimately commercialize any biologic candidate under our collaboration agreement, our business, financial condition, and results of operations could be materially and adversely affected.

We expect to continue to incur substantial losses and negative cash flow from operations and may not achieve or sustain profitability in the future.

For the three months ended March 31, 2024, we reported a net loss of $36.8 million. If and when we achieve profitability depends upon a number of factors, including the timing and recognition of milestones and other contingent payments and royalties received, the timing of revenue under our collaboration agreements, the amount of investments we make in our proprietary biologic candidates and the regulatory approval and market success of our biologic candidates. We may not be able to achieve and sustain profitability.

Other factors that will affect whether we achieve and sustain profitability include our ability, alone or together with our partners, to:

•develop drugs utilizing our technologies, either independently or in collaboration with other pharmaceutical or biotechnology companies;

•effectively estimate and manage clinical development costs, particularly the cost of the clinical studies for rezpegaldesleukin and NKTR-255;

•receive necessary regulatory and marketing approvals;

•maintain or expand manufacturing at necessary levels;

•achieve market acceptance of our partnered products;

•receive revenue or royalties on products that have been approved, marketed or submitted for marketing approval with regulatory authorities; and

•maintain sufficient funds to finance our activities.

Risks Related to Supply and Manufacturing

If we or our contract manufacturers are not able to manufacture biologic substance or substances in sufficient quantities that meet applicable quality standards, it could delay clinical studies, result in reduced sales or constitute a breach of our contractual obligations, any of which could significantly harm our business, financial condition and results of operations.

If we or our contract manufacturing organizations (CMOs) are not able to manufacture and supply sufficient drug quantities meeting applicable quality standards required to support large clinical studies or commercial manufacturing in a timely manner, it could delay our or our collaboration partners’ clinical studies or result in a breach of our contractual obligations, which could in turn reduce the potential commercial sales of our or our collaboration partners’ products. As a result, we could incur substantial costs and damages and any product sales or royalty revenue that we would otherwise be entitled to receive could be reduced, delayed or eliminated. In most cases, we rely on CMOs to manufacture and supply drug product for our clinical studies and those of our collaboration partners. The manufacturing of biologics involves significant risks and uncertainties related to the demonstration of adequate stability, sufficient purification of the drug substance and drug product, the identification and elimination of impurities, optimal formulations, process and analytical methods validations, and challenges in controlling for all of these variables. We have faced and may in the future face significant difficulties, delays and unexpected expenses as we validate third party CMOs required for drug supply to support our clinical studies and the clinical studies and products of our

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collaboration partners. Failure by us or our CMOs to supply API or drug products in sufficient quantities that meet all applicable quality requirements could result in supply shortages for our clinical studies or the clinical studies and commercial activities of our collaboration partners. Such failures could significantly and materially delay clinical trials and regulatory submissions or result in reduced sales, any of which could significantly harm our business prospects, results of operations and financial condition.

If any CMO with whom we contract fails to perform its obligations, we may be forced to manufacture the materials ourselves, for which we may not have the capabilities or resources, or enter into an agreement with a different CMO, which we may not be able to do on reasonable terms, if at all. In either scenario, our clinical trials or commercial distribution could be delayed significantly as we establish alternative supply sources. In some cases, the technical skills required to manufacture our products or biologic candidates may be unique or proprietary to the original CMO and we may have difficulty, or there may be contractual restrictions prohibiting us from, transferring such skills to a back-up or alternate supplier, or we may be unable to transfer such skills at all. In addition, if we are required to change CMOs for any reason, we will be required to verify that the new CMO maintains facilities and procedures that comply with quality standards and with all applicable regulations. We will also need to verify, such as through a manufacturing comparability study, that any new manufacturing process will produce our product according to the specifications previously submitted to or approved by the FDA or another regulatory authority. The delays associated with the verification of a new CMO could negatively affect our ability to develop biologic candidates or commercialize our products in a timely manner or within budget. Furthermore, a CMO may possess technology related to the manufacture of our biologic candidate that such CMO owns independently. This would increase our reliance on such a CMO or require us to obtain a license from such CMO in order to have another CMO manufacture our products or biologic candidates. In addition, in the case of the CMOs that supply our biologic candidates, changes in manufacturers often involve changes in manufacturing procedures and processes, which could require that we conduct bridging studies between our prior clinical supply used in our clinical trials and that of any new manufacturer. We may be unsuccessful in demonstrating the comparability of clinical supplies which could require the conduct of additional clinical trials.

Building and validating large scale clinical or commercial-scale manufacturing facilities and processes, recruiting and training qualified personnel and obtaining necessary regulatory approvals is complex, expensive and time consuming. In the past, we have encountered challenges in scaling up manufacturing to meet the requirements of large scale clinical trials without making modifications to the drug formulation, which may cause significant delays in clinical development. There continues to be substantial and unpredictable risk and uncertainty related to manufacturing and supply until such time as the commercial supply chain is validated and proven.

We purchase some of the starting material for biologics and biologic candidates from a single source or a limited number of suppliers, and the partial or complete loss of one of these suppliers could cause production delays, clinical trial delays, substantial loss of revenue and contract liability to third parties.

We often face very limited supply of a critical raw material that can only be obtained from a single, or a limited number of, suppliers, which could cause production delays, clinical trial delays, substantial lost revenue opportunities or contract liabilities to third parties. For example, there are only a limited number of qualified suppliers, and in some cases single source suppliers, for the raw materials included in our PEGylation and advanced polymer conjugate drug formulations. Any interruption in supply, diminution in quality of raw materials supplied to us or failure to procure such raw materials on commercially feasible terms could harm our business by delaying our clinical trials, impeding commercialization of approved drugs or increasing our costs.

Our manufacturing operations and those of our contract manufacturers are subject to laws and other governmental regulatory requirements, which, if not met, would have a material adverse effect on our business, results of operations and financial condition.

We and our CMOs are required in certain cases to maintain compliance with current good manufacturing practices (cGMP), including cGMP guidelines applicable to active pharmaceutical ingredients, and drug products, and with laws and regulations governing manufacture and distribution of controlled substances, and are subject to inspections by the FDA, or comparable agencies in other jurisdictions administering such requirements. We anticipate periodic regulatory inspections of our drug manufacturing facilities and the manufacturing facilities of our CMOs for compliance with applicable regulatory

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requirements. Any failure to follow and document our or our CMOs’ adherence to such cGMP and other laws and governmental regulations or satisfy other manufacturing and product release regulatory requirements may disrupt our ability to meet our manufacturing obligations to our customers, lead to significant delays in the availability of products for commercial use or clinical study, result in the termination or hold on a clinical study or delay or prevent filing or approval of marketing applications for our products. Failure to comply with applicable laws and regulations may also result in sanctions being imposed on us, including fines, injunctions, civil penalties, failure of regulatory authorities to grant marketing approval of our products, delays, suspension or withdrawal of approvals, license revocation, seizures, administrative detention, or recalls of products, operating restrictions and criminal prosecutions, any of which could harm our business. Regulatory inspections could result in costly manufacturing changes or facility or capital equipment upgrades to satisfy the FDA that our manufacturing and quality control procedures are in substantial compliance with cGMP. Manufacturing delays, for us or our CMOs, pending resolution of regulatory deficiencies or suspensions could have a material adverse effect on our business, results of operations and financial condition.

Risks Related to Business Operations

We depend on third parties to conduct the preclinical studies and clinical trials for our biologic candidates and any failure of those parties to fulfill their obligations according to protocol standards could harm our development plans and adversely affect our business.

We depend on our collaboration partners, independent clinical investigators, contract research organizations and other third-party service providers to conduct preclinical studies and clinical trials for our biologic candidates, including to monitor, record, manage and analyze data generated from these studies. We rely heavily on these parties for the successful execution of our preclinical studies and clinical trials. Though we are ultimately responsible for the results of their activities, many aspects of their activities are beyond our control, such as the timing, conduct and management of data developed through these studies and trials. For example, we are responsible for ensuring that each of our clinical trials is conducted in accordance with the general investigational plan and protocols for the trials, but the independent clinical investigators may prioritize other projects over ours or communicate issues regarding our biologic candidates to us in an untimely manner. Third parties may not complete activities on schedule or may not conduct our clinical trials in accordance with regulatory requirements, such as good laboratory practice or good clinical practice, or our stated protocols and any subsequent data generated may be deemed unacceptable. We rely on our collaboration partners and other third parties to manage, analyze and transmit clinical data, and those partners and third parties may not carry out the performance of their duties with the required degree of care or skill to ensure valid and scientifically reliable work products. The early termination of any of our clinical trial arrangements, the failure of third parties to comply with the regulations and requirements governing clinical trials, the failure of third parties to properly conduct our clinical trials, or erroneously reported data could hinder or delay the development, approval and commercialization of our product candidates and would adversely affect our business, results of operations and financial condition.

Our future depends on the proper management of our current and future business operations and their associated expenses.

Our business strategy requires us to manage our business to provide for the continued development of our proprietary and partnered biologic candidates. Our strategy also calls for us to manage the capital necessary to fund key programs through value-enhancing data and other milestones. If we are unable to manage effectively our current operations, our business, financial condition and results of operations may be adversely affected. If we are unable to effectively manage our expenses, we may find it necessary to reduce our personnel-related costs through reductions in our workforce, which could harm our operations, employee morale and impair our ability to retain and recruit talent. Furthermore, if adequate funds are not available, we may be required to obtain funds through arrangements with partners or other sources that may require us to relinquish rights to certain of our technologies, products or future economic rights that we would not otherwise relinquish or require us to enter into other dilutive financing arrangements on unfavorable terms.

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Because competition for highly qualified technical personnel is intense, we may not be able to attract and retain the personnel we need to support our operations and growth.

We must attract and retain experts in the areas of research, development (including clinical testing), manufacturing, regulatory and finance, and may need to attract and retain commercial, marketing and distribution experts and develop additional expertise in our existing personnel. We face intense competition from other biopharmaceutical companies, research and academic institutions and other organizations for qualified personnel. Many of the organizations with which we compete for qualified personnel have greater resources than we have. Because competition for skilled personnel in our industry is intense, companies such as ours sometimes experience high attrition rates with regard to their skilled employees. Further, in making employment decisions, job candidates often consider the value of the stock awards they are to receive in connection with their employment. Our equity incentive plan and employee benefit plans may not be effective in motivating or retaining our employees or attracting new employees, and significant volatility in the price of our stock may adversely affect our ability to attract or retain qualified personnel. Furthermore, as a result of our 2022 and 2023 Restructuring Plans, our employees may experience distractions or decreases in employee morale and we may experience increased levels of employee attrition and turnover, which would adversely affect our business. If we fail to attract new personnel or to retain and motivate our current personnel, our business and future growth prospects could be severely harmed.

We are dependent on our management team and key technical personnel, and the loss of any key manager or employee may impair our ability to develop our products effectively and may harm our business, operating results and financial condition.

Our success largely depends on the continued services of our executive officers and other key personnel. The loss of one or more members of our management team or other key employees could seriously harm our business, operating results and financial condition. The relationships that our key managers have cultivated within our industry make us particularly dependent upon their continued employment with us. We are also dependent on the continued services of our technical personnel because of the highly technical nature of our products and the regulatory approval process. Because our executive officers and key employees are not obligated to provide us with continued services, they could terminate their employment with us at any time without penalty. We do not have any post-employment noncompetition agreements with any of our employees and do not maintain key person life insurance policies on any of our executive officers or key employees.

Rising inflation rates have increased our operating costs and could negatively impact our operations.

Inflation rates, particularly in the United States, have increased recently to levels not seen in decades. Increased inflation has resulted in increased operating costs. In addition, the United States Federal Reserve has raised, and is expected to continue to raise, interest rates in response to concerns about inflation. Increases in interest rates, especially if coupled with reduced government spending and volatility in financial markets, may further increase economic uncertainty and heighten these risks.

Our business could be adversely affected by the effects of health epidemics, including the recent COVID-19 pandemic.

Our business could be adversely affected, directly or indirectly, by health epidemics in regions where we have concentrations of clinical trial sites or other business operations, including both our own manufacturing operations as well as the manufacturing operations of third parties upon whom we rely. Health epidemics, such as the COVID-19 pandemic and recent outbreak of respiratory syncytial virus (RSV) in the U.S., can negatively affect our clinical trials and those run by our collaborators or other third parties through delays in investigator recruitment, clinical site initiation, patient screening, or patient enrollment. In addition, health epidemics may cause disruptions in our supply chain or shortages in raw materials and equipment, which would affect our ability to manufacture our products and to supply drug candidates for clinical trials.

If the health epidemic is sufficiently severe and widespread, may require us to change the way in which can conduct our business, which may negatively result in unexpected expenses, decreased employee productivity and availability and employee work culture. Further, a severe and widespread epidemic may have a broad impact on global financial markets and could reduce our ability to access capital, which could in the future negatively affect our liquidity. In addition, a recession or market correction resulting from a health epidemic could materially affect our business and the value of our common stock.

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The ultimate effects of health epidemics is uncertain and subject to change and these effects could have a negative impact on our clinical trial timelines, operations, financial condition and prospects.

Risks Related to Intellectual Property, Litigation and Regulatory Concerns

If we or our partners do not obtain regulatory approval for our biologic candidates on a timely basis, or at all, or if the terms of any approval impose significant restrictions or limitations on use, our business, results of operations and financial condition will be negatively affected.

We or our partners may not obtain regulatory approval for biologic candidates on a timely basis, or at all, or the terms of any approval (which in some countries includes pricing approval) may impose significant restrictions or limitations on use. Biologic candidates must undergo rigorous animal and human testing and an extensive review process for safety and efficacy by the FDA and equivalent foreign regulatory authorities. The time required for obtaining regulatory decisions is uncertain and difficult to predict. The FDA and other U.S. and foreign regulatory authorities have substantial discretion, at any phase of development, to terminate clinical studies, require additional clinical development or other testing, delay or withhold registration and marketing approval and mandate product withdrawals, including recalls. Further, regulatory authorities have the discretion to analyze data using their own methodologies that may differ from those used by us or our partners, which could lead such authorities to arrive at different conclusions regarding the safety or efficacy of a biologic candidate. In addition, undesirable side effects caused by our biologic candidates could cause us or regulatory authorities to interrupt, delay or halt clinical trials and could result in a more restricted label or the delay or denial of regulatory approval by regulatory authorities.

Even if we or our partners receive regulatory approval of a product, the approval may limit the indicated uses for which the drug may be marketed. Our and our partnered drugs that have obtained regulatory approval, and the manufacturing processes for these products, are subject to continued review and periodic inspections by the FDA and other regulatory authorities. Discovery from such review and inspection of previously unknown problems may result in restrictions on marketed products or on us, including withdrawal or recall of such products from the market, suspension of related manufacturing operations or a more restricted label. The failure to obtain timely regulatory approval of drug candidates, any product marketing limitations or a product withdrawal would negatively impact our business, results of operations and financial condition.

We are a party to numerous collaboration agreements and other significant agreements which contain complex commercial terms that could result in disputes, litigation or indemnification liability that could adversely affect our business, results of operations and financial condition.

We currently derive, and expect to derive in the foreseeable future, substantially all of our revenue from collaboration agreements with biotechnology and pharmaceutical companies. These collaboration agreements contain complex commercial terms, including:

•clinical development and commercialization obligations that are based on certain commercial reasonableness performance standards that can often be difficult to enforce if disputes arise as to adequacy of our partner’s performance;

•research and development performance and reimbursement obligations for our personnel and other resources allocated to partnered biologic candidate development programs;

•clinical and commercial manufacturing agreements, some of which are priced on an actual cost basis for products supplied by us to our partners with complicated cost allocation formulas and methodologies;

•intellectual property ownership allocation between us and our partners for improvements and new inventions developed during the course of the collaboration;

•royalties on drug sales based on a number of complex variables, including net sales calculations, geography, scope of patent claim coverage, patent life, generic competitors, bundled pricing and other factors; and

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•indemnity obligations for intellectual property infringement, product liability and certain other claims.

We are a party to numerous significant collaboration agreements and other strategic transaction agreements (e.g. financings and asset divestitures) that contain complex representations and warranties, covenants and indemnification obligations. If we are found to have materially breached such agreements, we could be subject to substantial liabilities, which would harm our financial condition.

From time to time, we are involved in litigation matters involving the interpretation and application of complex terms and conditions of our agreements. One or more disputes may arise or escalate in the future regarding our collaboration agreements, transaction documents, or third-party license agreements that may ultimately result in costly litigation and unfavorable interpretation of contract terms, which would have a material adverse effect on our business, financial condition and results of operations.

We may not be able to obtain intellectual property licenses related to the development of our biologic candidates on a commercially reasonable basis, if at all.

Numerous pending and issued U.S. and foreign patent rights and other proprietary rights owned by third parties relate to pharmaceutical compositions, methods of preparation and manufacturing, and methods of use and administration. We cannot predict with any certainty which, if any, patent rights will be considered relevant to our or our collaboration partners’ technology or biologic candidates by authorities in the various jurisdictions where such rights exist, nor can we predict with certainty which, if any, of these rights will or may be asserted against us by third parties. In certain cases, we have existing licenses or cross-licenses with third parties; however, the sufficiency of the scope and adequacy of these licenses is very uncertain in view of the long development and commercialization cycles for biotechnology and pharmaceutical products. There can be no assurance that we can obtain a license to any technology that we determine we need on reasonable terms, if at all, or that we could develop or otherwise obtain alternate technology to avoid a need to secure a license. If we are required to enter into a license with a third party, our potential economic benefit for the products subject to the license will be diminished. If a license is not available on commercially reasonable terms or at all, we may be prevented from developing and commercializing the biologic, which could significantly harm our business, results of operations, and financial condition.

If any of our pending patent applications do not issue, or are deemed invalid following issuance, we may lose valuable intellectual property protection.

The patent positions of pharmaceutical and biotechnology companies, such as ours, are uncertain and involve complex legal and factual issues. We own more than 250 U.S. and 1,100 foreign patents and have a number of pending patent applications that cover various aspects of our technologies. There can be no assurance that patents that have issued will be held valid and enforceable in a court of law. Even for patents that are held valid and enforceable, the legal process associated with obtaining such a judgment is time consuming and costly. Additionally, issued patents can be subject to opposition, inter partes review, re-examinations or other proceedings that can result in the revocation of the patent or maintenance of the patent in amended form (and potentially in a form that renders the patent without commercially relevant and/or broad coverage). Further, our competitors may be able to circumvent and otherwise design around our patents. Even if a patent is issued and enforceable, because development and commercialization of pharmaceutical products can be subject to substantial delays, patents may expire prior to the commercialization of the biologic. Moreover, even if a patent encompassing a biologic has not expired prior to the biologic’s commercialization, the patent may only provide a short period of protection following the commercialization of the covered product. In addition, our patents may be subject to post grant proceedings, such as inter partes review and re-examinations, before the U.S. Patent and Trademark Office (or equivalent proceedings in other jurisdictions), which could result in a loss of the patent and/or substantial cost to us.

We have filed patent applications, and plan to file additional patent applications, covering various aspects of our PEGylation and advanced polymer conjugate technologies and our biologic candidates. There can be no assurance that the patent applications for which we apply will actually issue as patents, or do so with commercially relevant and/or broad coverage. The coverage claimed in a patent application can be significantly reduced before the patent is issued. The scope of our claim coverage can be critical to our ability to enter into licensing transactions with third parties and our right to receive royalties from our

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collaboration partnerships. Since publication of discoveries in scientific or patent literature often lags behind the date of such discoveries, we cannot be certain that we were the first inventor of inventions covered by our patents or patent applications. In addition, there is no guarantee that we will be the first to file a patent application directed to an invention.

An adverse outcome in any judicial proceeding involving intellectual property, including patents, could subject us to significant liabilities to third parties, require disputed rights to be licensed from or to third parties or require us to cease using the technology in dispute. In those instances where we seek an intellectual property license from another, we may not be able to obtain the license on a commercially reasonable basis, if at all, thereby raising concerns on our ability to freely commercialize our technologies or products.

We rely on trade secret protection and other unpatented proprietary rights for important proprietary technologies, and any loss of such rights could harm our business, results of operations and financial condition.

We rely on trade secret protection and other unpatented proprietary rights for our confidential and proprietary information. No assurance can be given that others will not independently develop substantially equivalent confidential and proprietary information or otherwise gain access to our trade secrets or disclose such technology, or that we can meaningfully protect our trade secrets. In addition, unpatented proprietary rights, including trade secrets and know-how, can be difficult to protect and may lose their value if they are independently developed by a third party or if their secrecy is lost. Any loss of trade secret protection or other unpatented proprietary rights could harm our business, results of operations and financial condition.

If product liability lawsuits are brought against us, we may incur substantial liabilities.

The manufacture, clinical testing, marketing and sale of medical products involve inherent product liability risks. If product liability costs exceed our product liability insurance coverage (or if we cannot secure product liability insurance), we may incur substantial liabilities that could have a severe negative impact on our financial position. Whether or not we are ultimately successful in any product liability litigation, such litigation would consume substantial amounts of our financial and managerial resources and might result in adverse publicity, all of which would impair our business. Additionally, we may not be able to maintain our clinical trial insurance or product liability insurance at an acceptable cost, if at all, and this insurance may not provide adequate coverage against potential claims or losses.

If we or current or future collaborators or service providers fail to comply with healthcare laws and regulations, we or they could be subject to enforcement actions and civil or criminal penalties.

Although we do not currently have any products on the market, once we begin commercializing our biologic candidates, if approved, we will be subject to additional healthcare statutory and regulatory requirements and enforcement by the federal and state governments of the jurisdictions in which we conduct our business. Healthcare providers, physicians and third-party payers play a primary role in the recommendation and prescription of any biologic candidates for which we obtain marketing approval. Our current and future arrangements with third-party payers and customers may expose us to broadly applicable fraud and abuse and other healthcare laws and regulations that may constrain the business or financial arrangements and relationships through which we market, sell and distribute our therapeutic candidates for which we obtain marketing approval. For more information, see “Business – Government Regulation - Other Healthcare Laws and Regulations.”

Ensuring that our future business arrangements with third parties comply with applicable healthcare laws and regulations could involve substantial costs. If our operations are found to be in violation of any such requirements, we may be subject to penalties, including administrative, civil or criminal penalties, imprisonment, monetary damages, the curtailment or restructuring of our operations, or exclusion from participation in government contracting, healthcare reimbursement or other government programs, including Medicare and Medicaid, any of which could adversely affect financial results. Although effective compliance programs can mitigate the risk of investigation and prosecution for violations of these laws, these risks cannot be entirely eliminated. Any action against us for an alleged or suspected violation could cause us to incur significant legal expenses and could divert our management’s attention from the operation of our business, even if our defense is successful. In addition, achieving and sustaining compliance with applicable laws and regulations may be costly to us in terms of money, time and resources.

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Healthcare legislative or regulatory reform measures may have a negative impact on our business and results of operations.

The U.S. and many foreign jurisdictions have enacted or proposed legislative and regulatory changes affecting the healthcare system. The U.S. government, state legislatures and foreign governments also have shown significant interest in implementing cost-containment programs to limit the growth of government- paid healthcare costs, including price controls, restrictions on reimbursement and requirements for substitution of generic products for branded prescription drugs. Governmental policy can also change the commercial potential of our product candidates, including efforts to increase patient access to lower-cost generic and biosimilar drugs. Additional changes that may affect our business include those governing enrollment in federal healthcare programs, reimbursement changes, rules regarding prescription drug benefits under the health insurance exchanges and fraud and abuse and enforcement. Continued implementation of the Affordable Care Act and the passage of additional laws and regulations may result in the expansion of new programs such as Medicare payment for performance initiatives, and may impact existing government healthcare programs, such as by improving the physician quality reporting system and feedback program. For more information regarding the risks related to recently enacted and future legislation please see “Business – Government Regulation – Legislative and Regulatory Landscape.”

We cannot predict the initiatives that may be adopted in the future. The continuing efforts of the government, insurance companies, managed care organizations and other payors of healthcare services to contain or reduce costs of healthcare and/or impose price controls may adversely affect:

•the demand for our product candidates, if we obtain regulatory approval;

•our ability to set a price that we believe is fair for our approved products;

•our ability to generate revenue and achieve or maintain profitability;

•the level of taxes that we are required to pay; and

• the availability of capital.

We expect that additional U.S. federal healthcare reform measures will be adopted in the future, any of which could limit the amounts that the U.S. federal government will pay for healthcare drugs and services, which could result in reduced demand for our drug candidates or additional pricing pressures. Individual states in the United States have also become increasingly active in passing legislation and implementing regulations designed to control pharmaceutical and biological product pricing, including price or patient reimbursement constraints, discounts, restrictions on certain drug access and marketing cost disclosure and transparency measures, and designed to encourage importation from other countries and bulk purchasing. Legally mandated price controls on payment amounts by third-party payors or other restrictions could harm our business, financial condition, results of operations and prospects. In addition, regional healthcare authorities and individual hospitals are increasingly using bidding procedures to determine what pharmaceutical products and which suppliers will be included in their prescription drug and other healthcare programs. This could reduce the ultimate demand for our drugs or put pressure on our drug pricing, which could negatively affect our business, financial condition, results of operations and prospects.

Disruptions to the normal functioning of the FDA and other government agencies could hinder their ability to perform and carry out important roles and activities on which the operation of our business relies, which could negatively impact our business.

The ability of the FDA to review and approve new products can be affected by a variety of factors, including government budget and funding levels, ability to hire and retain key personnel and accept the payment of user fees, and statutory, regulatory, and policy changes. In the past, average review times at the agency have fluctuated, and this may continue in the future. In addition, government funding of other agencies on which our operations may rely is subject to the political process, which is inherently fluid and unpredictable.

In addition, government shutdowns, if prolonged, could significantly impact the ability of government agencies upon which rely (such as the FDA and SEC) to timely review and process our regulatory submissions, which could have a material adverse effect on our business. Disruptions at the FDA and other agencies may slow the time necessary for new product

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candidates to be reviewed and/or approved by necessary government agencies, which would adversely affect our business. If a prolonged government shutdown occurs, it could significantly impact the ability of the FDA to timely review and process our regulatory submissions, which could have a material adverse effect on our business. Further, future government shutdowns could impact our ability to access the public markets and obtain necessary capital in order to properly capitalize and continue our operations.

We are involved in legal proceedings and may incur substantial litigation costs and liabilities that will adversely affect our business, financial condition and results of operations.

From time to time, we are involved in legal proceedings where we or other third parties are enforcing or seeking intellectual property rights, invalidating or limiting patent rights that have already been allowed or issued, or otherwise asserting proprietary rights through one or more potential legal remedies. Third parties have asserted, and may in the future assert, that we or our partners infringe their proprietary rights, such as patents and trade secrets, or have otherwise breached our obligations to them. A third party often bases its assertions on a claim that its patents cover our technology platform or biologic candidates or that we have misappropriated its confidential or proprietary information. Similar assertions of infringement could be based on future patents that may issue to third parties. In certain of our agreements with our partners, we are obligated to indemnify and hold harmless our collaboration partners from intellectual property infringement, product liability and certain other claims, which could cause us to incur substantial costs and liability if we are called upon to defend ourselves and our partners against any claims. We are also regularly involved in opposition proceedings at the European Patent Office and in inter partes review and re-examination proceedings at the U.S. Patent and Trademark Office where third parties seek to invalidate or limit the scope of our allowed patent applications or issued patents covering (among other things) our biologic candidates and platform technologies. If a third party obtains injunctive or other equitable relief against us or our partners, they could effectively prevent us, or our partners, from developing or commercializing, or deriving revenue from, certain biologics or biologic candidates in the U.S. and abroad. Costs associated with litigation, substantial damage claims, indemnification claims or royalties paid for licenses from third parties could have a material adverse effect on our business, financial condition and results of operations.

From time to time, we may also be involved in legal proceedings other than those related to intellectual property, including securities actions or derivative actions or other complaints.

On August 7, 2023, we filed a complaint in the United States District Court for the Northern District of California (the Court) against Lilly alleging, among other claims, breach of contract and breach of implied covenant of good faith and fair dealing (the Complaint), in connection with our collaboration with Lilly. Following the denial of its motion to dismiss the Complaint entirely, Lilly filed an answer that included counterclaims against us alleging breach of specified confidentiality provisions and defamation. The case is proceeding.

The cost to us in initiating or defending any litigation or other proceeding, even if resolved in our favor, could be substantial, and litigation would divert our management’s attention. Uncertainties resulting from the initiation and continuation of patent litigation or other proceedings could delay our research and development efforts or result in financial implications either in terms of seeking license arrangements or payment of damages or royalties. There is no guarantee that our insurance coverage for damages resulting from any litigation or the settlement would be sufficient and could result in substantial financial risk to the Company.

Given the nature of lawsuits and complaints, we cannot reasonably estimate a potential future loss or a range of potential future losses for any of the legal proceedings we may be involved in. However, an unfavorable resolution could potentially have a material adverse effect on our business, financial condition, and results of operations or prospects, and potentially result in paying monetary damages. We have recorded no liability for any litigation matters in our Consolidated Balance Sheets at March 31, 2024.

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If we are found in violation of privacy and data protection laws, we may be required to pay penalties, be subjected to scrutiny by regulators or governmental entities, or be suspended from participation in government healthcare programs, which may adversely affect our business, financial condition and results of operations.

Our business is subject to many laws and regulations intended to protect the privacy and data of individuals participating in our clinical trials and our employees, among others. For example, with regard to individuals participating in our clinical trials, these laws and regulations govern the safeguarding the privacy, integrity, availability, security and transmission of individually identifiable health information. In addition to federal laws and regulations in the United States, such as the HIPAA requirements relating to the privacy, security and transmission of individually identifiable health information, many state and foreign laws also govern the privacy and security of health information. These laws often differ from each other in significant ways, thus complicating compliance efforts. The global data protection landscape is rapidly evolving, and implementation standards and enforcement practices are likely to remain uncertain for the foreseeable future.

In the United States, California recently enacted the California Consumer Privacy Act (CCPA), which took effect on January 1, 2020. The CCPA gives California residents expanded rights to access and delete their personal information, opt out of certain personal information sharing, and receive detailed information about how their personal information is used. The CCPA provides for civil penalties for violations, as well as a private right of action for data breaches that is expected to increase data breach litigation. The CCPA has increased our compliance costs and may increase our potential liability. The CCPA has prompted a number of proposals for new federal and state privacy legislation. If passed, these proposals could increase our potential liability, increase our compliance costs and adversely affect our business.

The European Regulation 2016/679, known as the General Data Protection Regulation (GDPR), and the implementing legislation of EU Member States, which became effective on May 25, 2018, apply to the collection and processing of personal data, including health-related information, by companies located in the EU, or in certain circumstances, by companies located outside of the EU and processing personal information of individuals located in the EU. The GDPR is wide-ranging in scope and imposes strict obligations on the ability to process personal data, including health-related information, in particular in relation to their collection, use, disclosure and transfer. These include several requirements relating to, for example, (i) obtaining, in some situations, the consent of the individuals to whom the personal data relates, (ii) the information provided to the individuals about how their personal information is used, and (iii) ensuring the security and confidentiality of the personal data. The GDPR prohibits the transfer of personal data to countries outside of the European Economic Area (EEA), such as the United States, which are not considered by the European Commission to provide an adequate level of data protection. Potential pecuniary fines for noncompliant companies may be up to the greater of €20 million or 4% of annual global revenue.

To the extent that we are found liable for the inappropriate collection, storage, use or disclosure of protected information of individuals (such as employees and/or clinical patients protected by any privacy or data protection law), we could be subject to reputational harm, monetary fines (such as those imposed by the GDPR and CCPA), civil suits, civil penalties or criminal sanctions and requirements to disclose the breach, and the development of our biologic candidates could be delayed. In addition, we continue to be subject to new and evolving data protection laws and regulations from a variety of jurisdictions, and there is a risk that our systems and processes for managing and protecting data may be found to be inadequate, which could materially adversely affect our business, financial condition and results of operations.

Our operations may involve hazardous materials and are subject to environmental, health, and safety laws and regulations. Compliance with these laws and regulations is costly, and we may incur substantial liability arising from our activities involving the use of hazardous materials.

As a research-based biopharmaceutical company with significant research and development and manufacturing operations, we are subject to extensive environmental, health, and safety laws and regulations, including those governing the use of hazardous materials. Our research and development and manufacturing activities involve the controlled use of chemicals, radioactive compounds, and other hazardous materials. The cost of compliance with environmental, health, and safety regulations (including, but not limited to, the handling and disposal of both our hazardous and non-hazardous waste) is substantial. If an accident involving these materials or an environmental discharge were to occur, we could be held liable for any resulting damages, or face regulatory actions, which could exceed our resources or insurance coverage.

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Risk related to Investment and Securities

The price of our common stock has, and may continue to fluctuate significantly, which could result in substantial losses for investors and securities class action and shareholder derivative litigation.

Our stock price is volatile. During the three months ended March 31, 2024, based on closing prices on the NASDAQ Capital Market, the closing price of our common stock ranged from $0.49 to $0.96 per share. In response to volatility in the price of our common stock in the past, plaintiffs’ securities litigation firms have sought information from us and/or shareholders as part of their investigation into alleged securities violations and breaches of duties (among other corporate misconduct allegations). Following their investigations, plaintiffs’ securities litigation firms have often initiated legal action, including the filing of class action lawsuits, derivative lawsuits, and other forms of redress. We expect our stock price to remain volatile and we continue to expect the initiation of legal actions by plaintiffs’ securities litigation firms following share price fluctuations. A variety of factors may have a significant effect on the market price of our common stock, including the risks described in this section titled “Risk Factors” and the following:

•announcement of our 2022 Restructuring Plan and 2023 Restructuring Plan;

•announcements of data from, or material developments in, our clinical studies and those of our collaboration partners, including data regarding efficacy and safety, delays in clinical development, regulatory approval or commercial launch – in particular, the results from clinical studies of bempegaldesleukin and rezpegaldesleukin have had a significant impact on our stock price;

•the timing of outcomes from our clinical trials which can be difficult to predict particularly for clinical studies that have event-driven end points such as progression-free survival and overall survival;

•announcements by collaboration partners as to their plans or expectations related to biologic candidates and approved biologics in which we have a substantial economic interest;

•announcements regarding terminations or disputes under our collaboration agreements;

•fluctuations in our results of operations;

•developments in patent or other proprietary rights, including intellectual property litigation or entering into intellectual property license agreements and the costs associated with those arrangements;

•announcements of technological innovations or new therapeutic products that may compete with our approved partnered products or products under development;

•announcements of changes in governmental regulation affecting us or our competitors;

•litigation brought against us or third parties to whom we have indemnification obligations;

•public concern as to the safety of drug formulations developed by us or others;

•our financing needs and activities; and

•general economic, industry and market conditions, including the impacts of rising inflation and interest rates and global geopolitical tensions.

At times, our stock price has been volatile even in the absence of significant news or developments. The stock prices of biotechnology companies and securities markets generally have been subject to dramatic price swings in recent years. In addition, as a result of our lower stock price, we are no longer a well-known seasoned issuer, which otherwise would allow us to, among other things, file automatically effective shelf registration statements. As a result, any attempt to access the public capital markets will be more expensive and subject to delays. Additionally, if our common stock does not maintain a closing bid price of $1.00

51

per share in order to comply with the continued listing standards of the Nasdaq Capital Market, our common stock may become delisted, which could adversely affect our stock price, the flexibility of our investors to sell our common stock in the secondary market, and our ability to raise capital.

We have implemented certain anti-takeover measures, which make it more difficult to acquire us, even though such acquisitions may be beneficial to our stockholders.

Provisions of our certificate of incorporation and bylaws, as well as provisions of Delaware law, could make it more difficult for a third party to acquire us, even though such acquisitions may be beneficial to our stockholders. These anti-takeover provisions include:

•establishment of a classified board of directors such that not all members of the board may be elected at one time;

•lack of a provision for cumulative voting in the election of directors, which would otherwise allow less than a majority of stockholders to elect director candidates;

•the ability of our board to authorize the issuance of “blank check” preferred stock to increase the number of outstanding shares and thwart a takeover attempt;

•prohibition on stockholder action by written consent, thereby requiring all stockholder actions to be taken at a meeting of stockholders;

•establishment of advance notice requirements for nominations for election to the board of directors or for proposing matters that can be acted upon by stockholders at stockholder meetings; and

•limitations on who may call a special meeting of stockholders.

Further, provisions of Delaware law relating to business combinations with interested stockholders may discourage, delay or prevent a third party from acquiring us. These provisions may also discourage, delay or prevent a third party from acquiring a large portion of our securities or initiating a tender offer or proxy contest, even if our stockholders might receive a premium for their shares in the acquisition over the then-current market prices. We also have a change of control severance benefit plan, which provides for certain cash severance, stock award acceleration and other benefits in the event our employees are terminated (or, in some cases, resign for specified reasons) following an acquisition. This severance plan could discourage a third party from acquiring us.

General Risk Factors

We significantly rely on information technology systems and infrastructure, and any failure, inadequacy, damage, interruption, compromise or breach, or security lapse of that technology within our internal computer systems and infrastructure, or those of our partners, vendors, CROs, CMOs or other contractors or consultants, may result in a material disruption of our development programs and our operations and financial condition.

As part of our business, we collect, store and transmit large amounts of confidential information, proprietary or other sensitive information, including intellectual property and personal data. Despite the implementation of security measures, our internal computer systems and infrastructure or those of our partners, vendors, contract research organizations (CROs), contract manufacturing organizations (CMOs) and other contractors and consultants are vulnerable to loss, damage, compromise, interruption, denial-of-service, unauthorized access, or misappropriation. Cyber incidents have been increasing in frequency, levels of persistence, sophistication and intensity, and can include unauthorized activity by our employees, contractors and other third parties, as well as by third parties who use cyberattack techniques involving malware, hacking and phishing, social engineering and business email compromises, among others. Additionally, the risk of cyber-attacks or other privacy or data security incidents may be heightened as a result of an increase in the number of employees who adopted a remote working environment during and following the COVID-19 pandemic, which may be less secure and more susceptible to hacking attacks or other security compromises or breaches. Our information technology systems and infrastructure, and those of our partners,

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vendors, CROs, CMOs or other contractors or consultants are also vulnerable to natural disasters, terrorism, war, telecommunication and electrical failures and the types of interruption, compromise and damage described above. Any such compromise or disruption, no matter the origin, may cause an interruption of our operations. For instance, the loss or misappropriation of preclinical data or data from any clinical trial involving our biologic candidates could result in delays in our development and regulatory filing efforts and significantly increase our costs. In addition, the loss, corruption or unauthorized disclosure or misuse of our trade secrets, personal data or other confidential and/or proprietary or sensitive information could compromise the commercial viability of one or more of our programs, which would negatively affect our business. Also, the costs to us to investigate, mitigate and remediate cybersecurity incidents or compromises and comply with applicable legal obligations, including breach notification obligations to individuals, regulators, partners and others, could be significant and our reputation could be materially damaged. We could also be exposed to litigation or regulatory investigations or actions by state and federal governmental authorities and non-U.S. authorities, including fines, penalties, and other legal and financial exposure and liabilities.

Changes in tax law could adversely affect our business and financial condition.

Our business is subject to numerous international, federal, state, and other governmental laws, rules, and regulations that may adversely affect our operating results, including, taxation and tax policy changes, tax rate changes, new tax laws, or revised tax law interpretations, which individually or in combination may cause our effective tax rate to increase. In the U.S., the rules dealing with federal, state, and local income taxation are constantly under review by persons involved in the legislative process and by the Internal Revenue Service and the U.S. Treasury Department. Changes to tax laws (which changes may have retroactive application) could adversely affect us or holders of our common stock. In recent years, such changes have been made and changes are likely to continue to occur in the future. Future changes in tax laws could have a material adverse effect on our business, cash flow, financial condition or results of operations.

Global economic and political conditions may negatively affect us and may magnify certain risks that affect our business.

Our operations and performance may be affected by global economic and political conditions. For example, our operations and performance (or the operations and performance of our partners and service providers) may be negatively affected by political or civil unrest or military action, terrorist activity, and unstable governments and legal systems. For example, in late February 2022, Russia commenced a military invasion of Ukraine, and the sustained conflict in Ukraine, including the potential effects of sanctions and retaliatory cyber-attacks on the world economy and markets, has contributed to increased market volatility and uncertainty. In particular, sanctions imposed by the U.S., EU and other countries in response to the conflict between Russia and Ukraine and the potential response to such sanctions may have an adverse impact on our business, including our clinical trials, the financial markets and the global economy. In addition, in October 2023, conflicts arose in Israel and Gaza following terrorist attacks in Israel. As the conflicts between Ukraine and Russia and escalating conflicts in the Middle East continue, further sanctions, retaliatory attacks, market volatility and uncertainty may occur, any of which could have a material adverse effect on our business.

As a result of global economic and political conditions, some third-party payers may delay or be unable to satisfy their reimbursement obligations. Job losses or other economic hardships may also affect patients’ ability to afford healthcare as a result of increased co-pay or deductible obligations, greater cost sensitivity to existing co-pay or deductible obligations, lost healthcare insurance coverage or for other reasons. Our ability to conduct clinical trials in regions experiencing political or civil unrest could negatively affect clinical trial enrollment or the timely completion of a clinical trial. We believe the aforementioned economic conditions have led and could continue to lead to reduced demand for our and our collaboration partners’ drug products, which could have a material adverse effect on our product sales, business and results of operations

Further, with rising international trade tensions or sanctions, our business may be adversely affected following new or increased tariffs that result in increased global clinical trial costs as a result of international transportation of clinical drug supplies, as well as the costs of materials and products imported into the U.S. Tariffs, trade restrictions or sanctions imposed by the U.S. or other countries could increase the prices of our and our collaboration partners’ drug products, affect our and our collaboration partners’ ability to commercialize such drug products, or create adverse tax consequences in the U.S. or other

53

countries. As a result, changes in international trade policy, changes in trade agreements and the imposition of tariffs or sanctions by the U.S. or other countries could materially adversely affect our results of operations and financial condition.

Our business could be negatively impacted by corporate citizenship and sustainability matters.

There is an increased focus from certain investors, employees, and other stakeholders concerning corporate citizenship and sustainability matters, which include environmental concerns and social investments. We could fail to meet, or be perceived to fail to meet, the expectations of these certain investors, employees and other stakeholders concerning corporate citizenship and sustainability matters, thereby resulting in a negative impact to our business.

If natural disasters or other catastrophic events strike, our business may be harmed.

Our corporate headquarters, including a substantial portion of our research and development operations, are located in the San Francisco Bay Area, a region known for seismic activity and a potential terrorist target. In addition, we own facilities for the manufacture of products using our advanced polymer conjugate technologies in Huntsville, Alabama. There are no backup facilities for our manufacturing operations located in Huntsville, Alabama. In the event of an earthquake or other natural disaster, catastrophic event caused by climate change, political instability, civil unrest, or terrorist event in any of these locations, our ability to manufacture and supply materials for biologic candidates in development and our ability to meet our manufacturing obligations to our customers would be significantly disrupted and our business, results of operations and financial condition would be harmed. Our collaboration partners and important vendors and suppliers to us or our collaboration partners may also be subject to catastrophic events, such as earthquakes, floods, hurricanes, tornadoes and pandemics any of which could harm our business (including, for example, by disrupting supply chains important to the success of our business), results of operations and financial condition. We have not undertaken a systematic analysis of the potential consequences to our business, results of operations and financial condition from a major earthquake or other catastrophic event, such as a fire, sustained loss of power, terrorist activity or other disaster, and do not have a recovery plan for such disasters. In addition, our insurance coverage may not be sufficient to compensate us for actual losses from any interruption of our business that may occur.

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Item 2. Unregistered Sales of Equity Securities and Use of Proceeds

None, including no purchases of any class of our equity securities by us or any affiliate pursuant to any publicly announced repurchase plan in the three months ended March 31, 2024, other than the issuance of the pre-funded warrant to TCG and the repurchase of the shares issued to BMS as disclosed in Notes 5 and 7, respectively, to our Condensed Consolidated Financial Statements.

Item 3. Defaults Upon Senior Securities

None.

Item 4. Mine Safety Disclosures

Not applicable.

Item 5. Other Information

On May 8, 2024, Myriam J. Curet, M.D., F.A.C.S, a member of the Board of Directors (the “Board”) of the Company, decided to resign from her Board service and provided notice of her resignation from the Board as a Class I director and all committees thereof effective at the conclusion of the Company’s 2024 annual meeting of stockholders taking place on June 5, 2024; her resignation was not the result of any disagreement with the Company on any matter relating to its operations, policies or practices. The Company thanks Dr. Curet for her approximately five years of service as a director and wishes her well in her future endeavors.

Rule 10b5-1 Trading Arrangements

During the three months ended March 31, 2024, our directors and officers adopted or terminated the contracts, instructions or written plans for the purchase or sale of our securities set forth in the table below.

				Type of Trading Arrangement
Name	Title	Action	Adoption / Termination Date	Rule 10b5-1(1)	Non - Rule 10b5-1(2)	Total Shares of Common Stock to be Sold	Expiration Date
Robert Chess	Director	Adopt	March 14, 2024	X		up to 19,500	July 15, 2024

(1) Contract, instruction or written plan intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) under the Exchange Act.

(2) “Non-Rule 10b5-1 trading arrangement” as defined in Item 408(c) of Regulation S-K under the Exchange Act.

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Item 6. Exhibits

Except as so indicated in Exhibit 32.1, the following exhibits are filed as part of, or incorporated by reference into, this Quarterly Report on Form 10-Q.

Exhibit Number	Description of Documents
3.1(1)	Certificate of Incorporation of Inhale Therapeutic Systems (Delaware), Inc.
3.2(2)	Certificate of Amendment of the Amended Certificate of Incorporation of Inhale Therapeutic Systems, Inc.
3.3(3)	Certificate of Ownership and Merger of Nektar Therapeutics.
3.4(4)	Certificate of Ownership and Merger of Nektar Therapeutics AL, Corporation with and into Nektar Therapeutics.
3.5(5)	Amended and Restated Bylaws of Nektar Therapeutics.
10.1(6)	Amendment No. 1 to Purchase and Sale Agreement, dated December 16, 2020, by and between entities managed by Healthcare Royalty Management, LLC and Nektar Therapeutics.+
31.1(6)	Certification of Nektar Therapeutics’ principal executive officer required by Rule 13a-14(a) or Rule 15d-14(a).
31.2(6)	Certification of Nektar Therapeutics’ principal financial officer required by Rule 13a-14(a) or Rule 15d-14(a).
32.1*	Section 1350 Certifications.
101.SCH(6)	Inline XBRL Taxonomy Extension Schema With Embedded Linkbase Documents.
101.INS(6)	Inline XBRL Instance Document-the instance document does not appear in the Interactive Data File as its XBRL tags are embedded within the Inline XBRL document.
104(6)	Cover Page Interactive Data File (formatted as inline XBRL with applicable taxonomy extension information contained in Exhibits 101).

1.Incorporated by reference to Exhibit 3.1 to Nektar Therapeutics’ Quarterly Report on Form 10-Q, for the quarter ended June 30, 1998.

2.Incorporated by reference to Exhibit 3.3 to Nektar Therapeutics’ Quarterly Report on Form 10-Q, for the quarter ended June 30, 2000.

3.Incorporated by reference to Exhibit 3.1 to Nektar Therapeutics’ Current Report on Form 8-K, filed with the SEC on January 23, 2003.

4.Incorporated by reference to Exhibit 3.6 to Nektar Therapeutics’ Annual Report on Form 10-K, for the year ended December 31, 2009.

5.Incorporated by reference to Exhibit 3.1 to Nektar Therapeutics’ Current Report on Form 8-K, filed with the SEC on December 21, 2020.

6.Filed herewith.

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* Exhibit 32.1 is being furnished and shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liability of that section, nor shall such exhibit be deemed to be incorporated by reference in any registration statement or other document filed under the Securities Act of 1933, as amended, or the Securities Exchange Act, except as otherwise stated in such filing.

+ Certain confidential portions (indicated by brackets and asterisks) have been omitted from this exhibit in accordance with the rules of the Securities and Exchange Commission.
 

++ Management contract or compensatory plan or arrangement.

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SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

By:	/s/ SANDRA GARDINER
	Sandra Gardiner Interim Chief Financial Officer (Principal Financial Officer)
	Date: May 9, 2024

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EX-10.1(6)

Exhibit 10.1

[***] Certain information in this document has been omitted from this exhibit because it is both (i) not material and (ii) would be competitively harmful if publicly disclosed.

AMENDMENT NO. 1 TO PURCHASE AND SALE AGREEMENT

This AMENDMENT NO. 1 TO PURCHASE AND SALE AGREEMENT (this “First Amendment”), dated as of March 4, 2024, is by and among Nektar Therapeutics, a Delaware corporation (the “Seller”), Healthcare Royalty Partners IV, L.P., a Delaware limited liability partnership, HCRP Overflow Fund, L.P., a Delaware limited liability partnership, HCRX Investments Holdco, L.P., a Delaware limited liability partnership, and HCR Canary Fund, L.P., a Delaware limited liability partnership (collectively, the “Purchaser” or the “Purchasers”) and HCR Nektar SPV, LLC, solely in its capacity as a representative of the Purchasers (the “Purchaser Representative”). The Seller, the Purchaser and the Purchaser Representative may each be referred to herein individually as a “Party”, and collectively as the “Parties”. Capitalized terms used herein and not otherwise defined shall have the respective meanings given to such terms in the Agreement (defined below).

RECITALS

WHEREAS, the Seller and the Purchaser entered into that certain Purchase and Sale Agreement dated December 16, 2020 (the “Agreement”), in which, among other things, the Seller sold to the Purchaser, and the Purchaser acquired from the Seller, the Purchased Royalties;

WHEREAS, HCR Collateral Management (the original contracting party to the Agreement, as representative of the purchasers) assigned all of its rights and obligations in the Agreement to HCR Nektar SPV, LLC;

WHEREAS, HCR Potomac Fund, L.P. and HCR Stafford Fund, L.P. (original contracting parties to the Agreement, as purchasers) merged into HCRX Investments Holdco, L.P. and as a result, the assets and liabilities of HCR Potomac Fund, L.P. and HCR Stafford Fund, L.P. (including all of their rights and obligations in the Agreement) became assets and liabilities of HCRX Investments Holdco, L.P.; and

WHEREAS, the Parties desire to amend the Agreement in accordance with the terms set forth in this First Amendment.

NOW, THEREFORE, in consideration of the premises and the mutual agreements, representations and warranties set forth herein and of other good and valuable consideration, the receipt and adequacy of which are hereby acknowledged, the Parties covenant and agree as follows:

1.All references herein to paragraph or section location or schedules shall relate to the corresponding paragraph or section or schedule in the Agreement.

2.The definitions of “Initial Cap”, “Maximum Cap”, and “Royalty Cap” in Article 1 of the Agreement are hereby deleted in their entirety.

3.The definition of “Royalty Termination Date” in Article 1 of the Agreement is hereby deleted in its entirety and replaced as follows:

“Royalty Termination Date” means the date of the last Royalty payment under the License Agreements.”

4.Section 2.3 of the Agreement is hereby deleted in its entirety (including all subsections) and replaced as follows:

“Section 2.3 [Reserved].”

5.In full consideration for the amendments and other terms described herein, and subject to the terms and conditions set forth herein, the Purchaser (a) shall pay (or cause to be paid) to the Seller within three (3) Business Days following the date hereof FIFTEEN MILLION ($15,000,000), in immediately available funds by wire transfer to the Seller Account; and (b) [***].

6.The provisions of Article XI of the Agreement are hereby incorporated by reference into this First Amendment, mutatis mutandis.

7.Except as expressly amended by this First Amendment, all other terms of the Agreement shall continue in full force and effect and in accordance with its terms.

8.Representations and Warranties Regarding Authorizations

a.The Seller has all necessary corporate power and authority to execute and deliver this First Amendment, to perform its obligations hereunder and thereunder and to consummate the transactions contemplated hereby and thereby. The execution and delivery of this First Amendment and the performance by the Seller of its obligations hereunder and thereunder have been duly authorized by all necessary corporate action on the part of the Seller. This First Amendment has been duly executed and delivered by an authorized officer of the Seller. This First Amendment constitutes the legal, valid and binding obligation of the Seller, enforceable against the Seller in accordance with its terms, subject to applicable bankruptcy, insolvency, reorganization, moratorium or similar laws affecting creditors’ rights generally and general equitable principles.

b.Such Purchaser has all necessary trust power and authority to execute and deliver this First Amendment to which such Purchaser is a party, to perform its obligations hereunder and thereunder and to consummate the transactions contemplated hereby and thereby. The execution and delivery of this First Amendment to which such Purchaser is party and the performance by such Purchaser of its obligations hereunder and thereunder have been duly authorized by such Purchaser. This First Amendment to which such Purchaser is party has been duly executed and delivered by such Purchaser. This First Amendment to which such Purchaser is party constitutes the legal, valid and binding obligation of such Purchaser, enforceable against such Purchaser in accordance with its respective terms, subject to applicable bankruptcy, insolvency, reorganization, moratorium or similar laws affecting creditors’ rights generally, and general equitable principles.

c.The execution and delivery by such Purchaser of this First Amendment to which such Purchaser is party, the performance by such Purchaser of its obligations hereunder and thereunder and the consummation of the transactions contemplated hereby and thereby do not require any consent, approval, license, order, authorization or declaration from, notice to, action or registration by, or filing with, any Governmental Authority or any other Person, except for the filing of UCC financing statements.

d.The Purchaser Representative has all necessary trust power and authority to execute and deliver this First Amendment to which the Purchaser Representative is a party, to perform its obligations hereunder and thereunder and to consummate the transactions contemplated

2

hereby and thereby. The execution and delivery of this First Amendment to which the Purchaser Representative is party and the performance by the Purchaser Representative of its obligations hereunder and thereunder have been duly authorized by the Purchaser Representative. This First Amendment to which the Purchaser Representative is party has been duly executed and delivered by the Purchaser Representative. This First Amendment to which the Purchaser Representative is party constitutes the legal, valid and binding obligation of the Purchaser Representative, enforceable against the Purchaser Representative in accordance with its respective terms, subject to applicable bankruptcy, insolvency, reorganization, moratorium or similar laws affecting creditors’ rights generally, and general equitable principles.

e.The execution and delivery by the Purchaser Representative of this First Amendment to which the Purchaser Representative is party, the performance by the Purchaser Representative of its obligations hereunder and thereunder and the consummation of the transactions contemplated hereby and thereby do not require any consent, approval, license, order, authorization or declaration from, notice to, action or registration by, or filing with, any Governmental Authority or any other Person, except for the filing of UCC financing statements.

9.By way of confirmation (in view of Section 11.11 of the Agreement being incorporated by reference into this First Amendment, mutatis mutandis, under Section 6 above), this First Amendment may be signed in any number of counterparts, each of which shall be an original, with the same effect as if the signatures thereto and hereto were upon the same instrument. This First Amendment shall become effective when each Party shall have received a counterpart hereof signed by the other Party. Any counterpart may be executed by facsimile or other similar means of electronic transmission, including “PDF”, and such facsimile or other electronic transmission shall be deemed an original.

{SIGNATURE PAGE FOLLOWS}

IN WITNESS WHEREOF, the Parties have executed this Purchase and Sale Agreement as of the day and year first written above.

NEKTAR THERAPEUTICS

By: /s/ Howard W. Robin
Name: Howard W. Robin
Title: President and Chief Executive Officer

By: /s/ Jennifer Ruddock
Name: Jennifer Ruddock
Title: Chief Business Officer

3

IN WITNESS WHEREOF, the Parties have executed this Purchase and Sale Agreement as of the day and year first written above.

Healthcare Royalty Partners IV, L.P.

By: HealthCare Royalty GP IV, LLC, solely in its capacity as general partner of the Member

By: /s/ Clarke B. Futch___________________________

Name: Clarke B. Futch

Title: Managing Partner

HCRX Investments Holdco, L.P.

By: HCRX Master GP, LLC, solely in its capacity as general partner of the Member

By: /s/ Clarke B. Futch_______________________

Name: Clarke B. Futch

Title: Chairman and Chief Executive Officer

HCRP Overflow Fund, L.P.

By: HCRP Overflow Fund GP, LLC

By: Vanderbilt Overflow C GP, LLC

solely in its capacity as managing member of the general partner of the Member

By: /s/ Clarke B. Futch _________________________

Name: Clarke B. Futch

Title: Managing Member

HCR Canary Fund, L.P.

By: HCR Canary Fund GP, LLC, solely in its capacity as general partner of the Member

By: /s/ Clarke B. Futch ______________________

Name: Clarke B. Futch

Title: Managing Partner

hcr Nektar SPV, llc

By: /s/ Clarke B. Futch_____________________

Name: Clarke B. Futch

Title: Authorized Person

4

EX-31.1

Exhibit 31.1

CERTIFICATIONS

I, Howard W. Robin, certify that:

1.I have reviewed this Quarterly Report on Form 10-Q for the period ended March 31, 2024 of Nektar Therapeutics;

2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3.Based on my knowledge, the financial statements and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4.The registrant’s other certifying officer(s) and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)), for the registrant and have:

(a)Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

(b)Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

(c)Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

(d)Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting.

5.The registrant’s other certifying officer(s) and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

(a)All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

(b)Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: May 9, 2024	/s/ HOWARD W. ROBIN
	Howard W. Robin Chief Executive Officer, President and Director

EX-31.2

Exhibit 31.2

CERTIFICATIONS

I, Sandra Gardiner, certify that:

1.I have reviewed this Quarterly Report on Form 10-Q for the period ended March 31, 2024 of Nektar Therapeutics;

2.Based on my knowledge, this report does not contain any untrue statement of a material fact or omit to state a material fact necessary to make the statements made, in light of the circumstances under which such statements were made, not misleading with respect to the period covered by this report;

3.Based on my knowledge, the financial statements and other financial information included in this report, fairly present in all material respects the financial condition, results of operations and cash flows of the registrant as of, and for, the periods presented in this report;

4.The registrant’s other certifying officer(s) and I are responsible for establishing and maintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules 13a-15(f) and 15d-15(f)), for the registrant and have:

(a)Designed such disclosure controls and procedures, or caused such disclosure controls and procedures to be designed under our supervision, to ensure that material information relating to the registrant, including its consolidated subsidiaries, is made known to us by others within those entities, particularly during the period in which this report is being prepared;

(b)Designed such internal control over financial reporting, or caused such internal control over financial reporting to be designed under our supervision, to provide reasonable assurance regarding the reliability of financial reporting and the preparation of financial statements for external purposes in accordance with generally accepted accounting principles;

(c)Evaluated the effectiveness of the registrant’s disclosure controls and procedures and presented in this report our conclusions about the effectiveness of the disclosure controls and procedures, as of the end of the period covered by this report based on such evaluation; and

(d)Disclosed in this report any change in the registrant’s internal control over financial reporting that occurred during the registrant’s most recent fiscal quarter (the registrant’s fourth fiscal quarter in the case of an annual report) that has materially affected, or is reasonably likely to materially affect, the registrant’s internal control over financial reporting.

5.The registrant’s other certifying officer(s) and I have disclosed, based on our most recent evaluation of internal control over financial reporting, to the registrant’s auditors and the audit committee of the registrant’s board of directors (or persons performing the equivalent functions):

(a)All significant deficiencies and material weaknesses in the design or operation of internal control over financial reporting which are reasonably likely to adversely affect the registrant’s ability to record, process, summarize and report financial information; and

(b)Any fraud, whether or not material, that involves management or other employees who have a significant role in the registrant’s internal control over financial reporting.

Date: May 9, 2024	/s/ SANDRA GARDINER
	Sandra Gardiner Interim Chief Financial Officer (Principal Financial Officer)

EX-32.1

Exhibit 32.1

SECTION 1350 CERTIFICATIONS*

Pursuant to the requirement set forth in Rule 13a-14(b) of the Securities Exchange Act of 1934, as amended (the “Exchange Act”) and Section 1350 of Chapter 63 of Title 18 of the United States Code (18 U.S.C. §1350), Howard W. Robin, Chief Executive Officer, President and Director of Nektar Therapeutics (the “Company”), and Sandra Gardiner, Interim Chief Financial Officer (Principal Financial Officer) of the Company, each hereby certifies that, to the best of his or her knowledge:

1.The Company’s Quarterly Report on Form 10-Q for the three months ended March 31, 2024, to which this Certification is attached as Exhibit 32.1 (the “Periodic Report”), fully complies with the requirements of Section 13(a) or Section 15(d) of the Exchange Act; and

2.The information contained in the Periodic Report fairly presents, in all material respects, the financial condition and results of operations of the Company.

Date: May 9, 2024
/s/ HOWARD W. ROBIN	/s/ SANDRA GARDINER
Howard W. Robin Chief Executive Officer, President and Director	Sandra Gardiner Interim Chief Financial Officer (Principal Financial Officer)

___________________________________________

* This certification accompanies the Form 10-Q to which it relates, is not deemed filed with the Securities and Exchange Commission and is not to be incorporated by reference into any filing of the Company under the Securities Act of 1933, as amended, or the Securities Exchange Act of 1934, as amended (whether made before or after the date of the Form 10-Q), irrespective of any general incorporation language contained in such filing.

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Document Transition Report	false
Entity File Number	0-24006
Entity Registrant Name	NEKTAR THERAPEUTICS
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	94-3134940
Entity Address, Address Line One	455 Mission Bay Boulevard South
Entity Address, City or Town	San Francisco
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94158
City Area Code	415
Local Phone Number	482-5300
Title of 12(b) Security	Common Stock, $0.0001 par value
Trading Symbol	NKTR
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		183,624,620
Amendment Flag	false
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q1
Entity Central Index Key	0000906709
Current Fiscal Year End Date	--12-31

XML

CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 48,642	$ 35,277
Short-term investments	240,596	268,339
Accounts receivable	3,617	1,205
Inventory, net	16,238	16,101
Other current assets	10,743	9,779
Total current assets	319,836	330,701
Property, plant and equipment, net	17,475	18,856
Long-term investments	36,778	25,825
Operating lease right-of-use assets	17,267	18,007
Other assets	4,656	4,644
Total assets	396,012	398,033
Current liabilities:
Accounts payable	8,757	9,848
Accrued expenses	24,281	22,162
Operating lease liabilities, current portion	19,368	19,259
Total current liabilities	52,406	51,269
Operating lease liabilities, less current portion	94,710	98,517
Liabilities related to the sales of future royalties, net	117,857	112,625
Other long-term liabilities	4,334	4,635
Total liabilities	269,307	267,046
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.0001 par value; 10,000 shares authorized; no shares designated or outstanding at March 31, 2024 or December 31, 2023, respectively	0	0
Common stock, $0.0001 par value; 300,000 shares authorized; 191,909 shares and 191,384 shares issued at March 31, 2024 and December 31, 2023, respectively; 183,624 shares and 191,384 shares outstanding at March 31, 2024 and December 31, 2023, respectively;	19	19
Capital in excess of par value	3,644,140	3,608,137
Treasury stock, at cost; 8,285 shares as of March 31, 2024 and none as of December 31, 2023, respectively	(3,000)	0
Accumulated other comprehensive income (loss)	(403)	80
Accumulated deficit	(3,514,051)	(3,477,249)
Total stockholders’ equity	126,705	130,987
Total liabilities and stockholders’ equity	$ 396,012	$ 398,033

XML

CONDENSED CONSOLIDATED BALANCE SHEETS (Parenthetical) - $ / shares	Mar. 31, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Preferred stock, shares designated (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	300,000,000	300,000,000
Common stock shares, issued (in shares)	191,909,000	191,384,000
Common stock, shares outstanding (in shares)	183,624,000	191,384,000
Treasury Stock, Common, Shares	8,285,000	0

XML

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Revenue:
Total revenue	$ 21,639	$ 21,594
Operating costs and expenses:
Cost of goods sold	8,534	7,060
Research and development	27,408	30,469
General and administrative	20,149	21,081
Restructuring, impairment and costs of terminated program	975	21,193
Impairment of goodwill	0	76,501
Total operating costs and expenses	57,066	156,304
Loss from operations	(35,427)	(134,710)
Non-operating income (expense):
Non-cash interest expense on liabilities related to the sales of future royalties	(5,531)	(6,405)
Interest income	4,220	4,335
Other income (expense), net	(99)	(301)
Total non-operating income (expense), net	(1,410)	(2,371)
Loss before provision for income taxes	(36,837)	(137,081)
Benefit for income taxes	(35)	(63)
Net loss	$ (36,802)	$ (137,018)
Basic net loss per share (in dollars per share)	$ (0.19)	$ (0.73)
Diluted net loss per share (in dollars per share)	$ (0.19)	$ (0.73)
Weighted average shares outstanding used in computing basic net loss per share (in shares)	194,746	188,875
Weighted average shares outstanding used in computing diluted net loss per share (in shares)	194,746	188,875
Product sales
Revenue:
Total revenue	$ 6,034	$ 4,718
Non-cash royalty revenue related to the sales of future royalties
Revenue:
Total revenue	15,508	16,861
License, collaboration and other revenue
Revenue:
Total revenue	$ 97	$ 15

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CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Statement of Comprehensive Income [Abstract]
Net loss	$ (36,802)	$ (137,018)
Other comprehensive income (loss):
Net unrealized gain (loss) on available-for-sale securities	(475)	1,087
Net foreign currency translation gain (loss)	(8)	139
Other comprehensive income (loss)	(483)	1,226
Comprehensive loss	$ (37,285)	$ (135,792)

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CONDENSED CONSOLIDATED STATEMENTS OF STOCKHOLDERS’ EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Shares	Treasury Stock	Capital in Excess of Par Value	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Beginning balance (in shares) at Dec. 31, 2022		188,560
Beginning balance at Dec. 31, 2022	$ 366,638	$ 19		$ 3,574,719	$ (6,907)	$ (3,201,193)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued under equity compensation plans (in shares)		675
Stock-based compensation	10,019			10,019
Comprehensive income (loss)	(135,792)				1,226	(137,018)
Ending balance (in shares) at Mar. 31, 2023		189,235
Ending balance at Mar. 31, 2023	$ 240,865	$ 19		3,584,738	(5,681)	(3,338,211)
Beginning balance (in shares) at Dec. 31, 2023	191,384	191,384
Beginning balance at Dec. 31, 2023	$ 130,987	$ 19		3,608,137	80	(3,477,249)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued under equity compensation plans (in shares)		525
Shares issued under equity compensation plans	3			3
Stock-based compensation	6,000			6,000
Repurchase of common stock from Bristol-Myers Squibb (in shares)		(8,285)	8,285
Repurchase of common stock from Bristol-Myers Squibb	(3,000)		$ (3,000)
Issuance of prefunded warrant	30,000			30,000
Comprehensive income (loss)	$ (37,285)				(483)	(36,802)
Ending balance (in shares) at Mar. 31, 2024	183,624	183,624	8,285
Ending balance at Mar. 31, 2024	$ 126,705	$ 19	$ (3,000)	$ 3,644,140	$ (403)	$ (3,514,051)

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CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Cash flows from operating activities:
Net loss	$ (36,802)	$ (137,018)
Adjustments to reconcile net loss to net cash used in operating activities:
Non-cash royalty revenue related to the sales of future royalties	(15,508)	(16,861)
Non-cash interest expense on liabilities related to the sales of future royalties	5,531	6,405
Stock-based compensation	6,000	10,019
Depreciation and amortization	1,607	2,302
Deferred income tax expense	(38)	(1,812)
Impairment of right-of-use assets and property, plant and equipment	0	13,200
Impairment of goodwill	0	76,501
Provision for net realizable value of inventory	1,006	952
Amortization of premiums (discounts), net and other non-cash transactions	(3,063)	(3,129)
Changes in operating assets and liabilities:
Accounts receivable	(2,412)	2,986
Inventory	(1,143)	(1,985)
Operating leases, net	(2,958)	(1,786)
Other assets	(976)	5,591
Accounts payable	(988)	(8,920)
Accrued expenses	1,856	1,640
Net cash used in operating activities	(47,888)	(51,915)
Cash flows from investing activities:
Purchases of investments	(105,059)	(107,012)
Maturities of investments	124,474	148,043
Purchases of property, plant and equipment	(157)	(433)
Net cash provided by investing activities	19,258	40,598
Cash flows from financing activities:
Proceeds from shares issued under equity compensation plans	3	0
Proceeds from issuance of pre-funded warrant	30,000	0
Proceeds from sale of future royalties	15,000	0
Repurchase of common stock from Bristol-Myers Squibb	(3,000)	0
Net cash provided by financing activities	42,003	0
Effect of foreign exchange rates on cash and cash equivalents	(8)	45
Net increase (decrease) in cash and cash equivalents	13,365	(11,272)
Cash and cash equivalents at beginning of period	35,277	88,227
Cash and cash equivalents at end of period	$ 48,642	$ 76,955

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Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Pay vs Performance Disclosure
Net Income (Loss)	$ (36,802)	$ (137,018)

XML

Insider Trading Arrangements
shares in Thousands

3 Months Ended

Mar. 31, 2024

shares

Trading Arrangements, by Individual

Material Terms of Trading Arrangement

Rule 10b5-1 Trading Arrangements

During the three months ended March 31, 2024, our directors and officers adopted or terminated the contracts, instructions or written plans for the purchase or sale of our securities set forth in the table below.

				Type of Trading Arrangement
Name	Title	Action	Adoption / Termination Date	Rule 10b5-1(1)	Non - Rule 10b5-1(2)	Total Shares of Common Stock to be Sold	Expiration Date
Robert Chess	Director	Adopt	March 14, 2024	X		up to 19,500	July 15, 2024

(1) Contract, instruction or written plan intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) under the Exchange Act.

(2) “Non-Rule 10b5-1 trading arrangement” as defined in Item 408(c) of Regulation S-K under the Exchange Act.

Name

Robert Chess

Title

Director

Rule 10b5-1 Arrangement Adopted

true

Non-Rule 10b5-1 Arrangement Adopted

false

Adoption Date

March 14, 2024

Aggregate Available

19,500

Trd Arr Expiration Date

July 15, 2024

XML

Organization and Summary of Significant Accounting Policies

3 Months Ended

Mar. 31, 2024

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Organization and Summary of Significant Accounting Policies

Note 1 — Organization and Summary of Significant Accounting Policies

Organization

We are a clinical stage, research-based drug discovery biopharmaceutical company headquartered in San Francisco, California and incorporated in Delaware, focused on discovering and developing innovative medicines in the field of immunotherapy. Within this growing field, we direct our efforts toward creating new immunomodulatory agents that selectively induce, amplify, attenuate or prevent immune responses in order to achieve desired therapeutic outcomes. Our pipeline of clinical-stage and preclinical-stage immunomodulatory agents targets the treatment of autoimmune diseases (e.g. rezpegaldesleukin and NKTR-0165, respectively) and cancer (e.g. NKTR-255).

Our research and development activities have required significant ongoing investment to date and are expected to continue to require significant investment. As a result, we expect to continue to incur substantial losses and negative cash flows from operations in the future. We have financed our operations primarily through cash generated from licensing, collaboration and manufacturing agreements and financing transactions. As of March 31, 2024, we had approximately $326.0 million in cash and investments in marketable securities.

Financing Transactions

During the three months ended March 31, 2024, we entered into the following transactions:

•On February 12, 2024, for total cash consideration paid of $3.0 million, we repurchased from Bristol Myers Squibb Company (BMS) 8.3 million shares of Nektar's common stock that were previously sold to BMS, which we report as treasury stock on our Condensed Consolidated Balance Sheets. See Note 6 for additional information.

•On March 4, 2024, we entered into a Securities Purchase Agreement with TCG Crossover Fund II, L.P. (TCG), pursuant to which we issued a pre-funded warrant to TCG to purchase 25,000,000 shares of Nektar’s common stock for gross proceeds of $30.0 million (or a purchase price of $1.20 per share of common stock that can be issued upon exercise of the pre-funded warrant). See Note 5 for additional information.

•On March 4, 2024, for total cash consideration received of $15.0 million, we entered into an amendment (the Amendment) with entities managed by Healthcare Royalty Management, LLC (collectively, HCR) to remove the cap on royalties previously sold to HCR under a Purchase and Sale Agreement (the 2020 Purchase and Sale Agreement). See Note 3 for additional information.

Restructuring Plans

In April 2022, we announced the termination of the bempegaldesleukin program and a new strategic reorganization and cost restructuring plan (together, the 2022 Restructuring Plan), pursuant to which we completed an approximate 70% reduction of our workforce during 2022. We also decided to seek a sublease for certain of our leased premises in San Francisco, CA, including all of our office leased space on Third St. and portions of our office and laboratory space on Mission Bay Blvd. South.

In April 2023, we announced Eli Lilly and Company's (Lilly) decision to terminate our license agreement (the Lilly Agreement) for the development of rezpegaldesleukin, as well as a new strategic reprioritization and cost restructuring plan (the 2023 Restructuring Plan). Under the 2023 Restructuring Plan, we reduced our San Francisco-based workforce by approximately 60%. In addition, under the 2023 Restructuring Plan, we decided to seek a sublease for our remaining office and laboratory space on Mission Bay Blvd. South which we had not planned to sublease pursuant to the 2022 Restructuring Plan.

We have regained full rights to rezpegaldesleukin from Lilly, and we initiated a Phase 2b study of rezpegaldesleukin in patients with moderate-to-severe atopic dermatitis in October 2023 and a Phase 2b study of rezpegaldesleukin in patients with severe-to-very severe alopecia areata in March 2024. We will also explore other auto-immune indications for the development of rezpegaldesleukin.

We have incurred significant costs resulting from the 2022 and 2023 Restructuring Plans. See Note 7 for additional information on the effect on our Condensed Consolidated Financial Statements.

Basis of Presentation and Principles of Consolidation

Our Condensed Consolidated Financial Statements include the financial position, results of operations and cash flows of Nektar Therapeutics and our wholly-owned subsidiaries. We have eliminated all intercompany accounts and transactions in consolidation.

We prepared our Condensed Consolidated Financial Statements following the requirements of the Securities and Exchange Commission (SEC) for interim reporting. As permitted under those rules, we may condense or omit certain footnotes or other financial information that are normally required by U.S. generally accepted accounting principles (GAAP) for annual periods. In the opinion of management, these financial statements include all normal and recurring adjustments that we consider necessary for the fair presentation of our financial position and operating results.

Our Condensed Consolidated Financial Statements are denominated in U.S. dollars. Accordingly, changes in exchange rates between the applicable foreign currency and the U.S. dollar will affect the translation of each foreign subsidiary’s financial results into U.S. dollars for purposes of reporting our consolidated financial results. We include translation gains and losses in accumulated other comprehensive loss in the stockholders’ equity section of our Condensed Consolidated Balance Sheets.

Our comprehensive loss consists of our net loss plus our foreign currency translation gains and losses and unrealized gains and losses on available-for-sale securities. There were no significant reclassifications out of accumulated other comprehensive income (loss) to the statements of operations during the three months ended March 31, 2024 and 2023.

The accompanying Condensed Consolidated Financial Statements are unaudited. The Condensed Consolidated Balance Sheet data as of December 31, 2023 was derived from the audited consolidated financial statements which are included in our Annual Report on Form 10-K for the year ended December 31, 2023 filed with the SEC on March 5, 2024. The information included in this Quarterly Report on Form 10-Q should be read in conjunction with the consolidated financial statements and the accompanying notes to those financial statements.

Revenue, expenses, assets, and liabilities can vary during each quarter of the year. The results and trends in these interim Condensed Consolidated Financial Statements are not necessarily indicative of the results to be expected for the full year or any other period.

Use of Estimates

The preparation of consolidated financial statements in conformity with U.S. generally accepted accounting principles (GAAP) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenue and expenses during the reporting period. Accounting estimates and assumptions are inherently uncertain.

Actual results could differ materially from those estimates and assumptions. As appropriate, we assess estimates each period, update them to reflect current information, and generally reflect any changes in estimates in the period first identified.

Significant Concentrations

Our customers are primarily pharmaceutical companies that are located in the U.S. and Europe and with whom we have multi-year arrangements. Our accounts receivable balance contains billed and unbilled trade receivables from product sales, milestones (to the extent that they have been achieved and are due from the counterparty), and other contingent payments, as well as reimbursable costs from collaborative research and development agreements. We generally do not require collateral from our

customers. We perform a regular review of our customers’ credit risk and payment histories, including payments made after period end. Historically, we have not experienced credit losses from our accounts receivable. We have not recorded reserves for credit losses for the three months ended March 31, 2024 and 2023, nor have recorded such an allowance as of March 31, 2024 or December 31, 2023.

We are dependent on our suppliers and contract manufacturers to provide raw materials and drugs of appropriate quality and reliability and to meet applicable contract and regulatory requirements. In certain cases, we rely on single sources of supply of one or more critical materials. Consequently, in the event that supplies are delayed or interrupted for any reason, our ability to develop and produce our drug candidates or our ability to meet our supply obligations could be significantly impaired, which could have a material adverse effect on our business, financial condition and results of operations.

For our available-for-sale securities, we have significant concentrations of issuers in the banking and financial services industries. While our investment policy requires that we only invest in highly-rated securities and limit our exposure to any single issuer, various factors may materially affect the financial condition of issuers. Additionally, pursuant to our investment policy, we may sell securities before maturity if the issuer’s credit rating has been downgraded below our minimum credit rating requirements, which may result in a loss on the sale. Accordingly, if various factors result in downgrades below our minimum credit rating requirements and if we decide to sell these securities, we may experience losses on such sales.

Treasury Stock

We record treasury stock activities under the cost method. Treasury stock is included in authorized and issued shares but excluded from outstanding shares. The re-issuance of treasury stock is accounted for on a first in, first-out basis and any differences between the cost of treasury stock and the re-issuance proceeds are charged or credited to additional paid-in capital.

Restructuring

We recognize restructuring charges related to reorganization plans that have been committed to by management when liabilities have been incurred. In connection with these activities, we record restructuring charges at fair value for:

•contractual or other employee termination benefits provided that the obligations result from services already rendered based on rights that vest or accumulated when the payment of benefits becomes probable and the amount can be reasonably estimated,

•one-time employee termination benefits on the communication date from management to the employees provided that management has committed to a plan of termination, the plan identifies the employees and their expected termination dates, the details of termination benefits are complete, and it is unlikely that changes to the plan will be made or the plan will be withdrawn,

•contract termination costs when we cancel the contract in accordance with its terms, and

•costs to be incurred over the remaining contract term without economic benefit to us at the cease-use date.

For one-time employee terminations benefits, we recognize the liability in full on the communication date when future services are not required or amortize the liability ratably over the service period, if required. The fair value of termination benefits reflects our estimates of expected utilization of certain Company-funded post-employment benefits.

See Note 7 for additional information on the severance expense that we recognized for employees terminated in connection with our reductions-in-force.

Impairment of Goodwill

Goodwill is assessed for impairment on an annual basis and whenever events and circumstances indicate that it may be impaired. Factors that may indicate potential impairment and trigger an impairment test include, but are not limited to, current economic, market and geopolitical conditions, including a significant, sustained decline in our stock price and market

capitalization compared to the net book value; an adverse change in legal factors, business climate or operational performance of the business; or significant changes in the ability of the reporting unit to generate positive cash flows for our strategic business objectives. If the carrying value of the reporting unit, including goodwill, exceeds the reporting unit’s fair value, we will recognize a goodwill impairment loss, and we will write down goodwill such that the carrying value of the reporting unit equals its fair value, provided that we cannot reduce goodwill below zero.

See Note 8 for additional information regarding the impairment charges we recorded during the three months ended March 31, 2023 in connection with our goodwill.

Long-Lived Asset Impairment

We assess the impairment of long-lived assets whenever events or changes in business circumstances indicate that the carrying amounts of the assets may not be fully recoverable. In the case of property, plant and equipment and right-of-use assets for our leases, we determine whether there has been an impairment by comparing the carrying value of the asset to the anticipated undiscounted net cash flows associated with the asset. If such cash flows are less than the carrying value, we write down the asset to its fair value, which may be measured as anticipated net cash flows associated with the asset, discounted at a rate that we believe a market participant would utilize to reflect the risks associated with the cash flows, such as credit risk.

See Note 7 for additional information regarding the impairment charges we recorded in connection with our leased facilities and certain property and equipment.

Net Loss per Share

For all periods presented in the Condensed Consolidated Statements of Operations, the net loss available to common stockholders is equal to the reported net loss. We calculate basic net loss per share based on the weighted-average number of common shares outstanding, including the pre-funded warrant, during the periods presented. Shares of common stock into which the pre-funded warrant may be exercised are considered outstanding for the purposes of computing basic net loss per share because the shares may be issued for little or no consideration, are fully vested and are exercisable after the original issuance date. For the three months ended March 31, 2024 and 2023, basic and diluted net loss per share are the same due to our net losses and the requirement to exclude potentially dilutive securities which would have an antidilutive effect on net loss per share. We excluded shares underlying the weighted average outstanding stock options, restricted stock units (RSUs) and performance stock units (PSUs), as follows (in thousands):

	Three Months Ended March 31,
	2024		2023
Potentially dilutive securities		26,973		22,798

XML

Cash and Investments in Marketable Securities

3 Months Ended

Mar. 31, 2024

Fair Value Disclosures [Abstract]

Cash and Investments in Marketable Securities

Note 2 — Cash and Investments in Marketable Securities

Cash and investments in marketable securities, including cash equivalents, are as follows (in thousands):

	Estimated Fair Value at
	March 31, 2024		December 31, 2023
Cash and cash equivalents	$	48,642	$	35,277
Short-term investments		240,596		268,339
Long-term investments		36,778		25,825
Total cash and investments in marketable securities	$	326,016	$	329,441

Our portfolio of cash and investments in marketable securities includes (in thousands):

		March 31, 2024									December 31, 2023
	Fair Value Hierarchy Level	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value		Fair Value
Corporate notes and bonds	2	$	75,745	$	2	$	(163	)	$	75,584	$	38,882
Corporate commercial paper	2		211,955		—		(261	)		211,694		255,241
Obligations of U.S. government agencies	2		3,457		—		(3	)		3,454		—
Available-for-sale investments		$	291,157	$	2	$	(427	)	$	290,732	$	294,123
Money market funds	1									15,959		2,359
Certificates of deposit	2									13,898		15,116
Cash	N/A									5,427		17,843
Total cash and investments in marketable securities									$	326,016	$	329,441

For the three months ended March 31, 2024 and 2023, there were no transfers between Level 1 and Level 2 of the fair value hierarchy. At December 31, 2023, our gross unrealized gains and losses were insignificant.

XML

Condensed Consolidated Financial Statement Details

3 Months Ended

Mar. 31, 2024

Inventory Disclosure [Abstract]

Condensed Consolidated Financial Statement Details

Note 3 — Condensed Consolidated Financial Statement Details

Inventory

Inventory consists of the following (in thousands):

	March 31, 2024		December 31, 2023
Raw materials	$	1,936	$	1,861
Work-in-process		9,962		12,880
Finished goods		4,340		1,360
Total inventory, net	$	16,238	$	16,101

We manufacture finished goods inventory upon receipt of firm purchase orders, and we may manufacture certain intermediate work-in-process materials and purchase raw materials based on purchase forecasts from our partners. We include direct materials, direct labor, and manufacturing overhead in inventory and determine cost on a first-in, first-out basis for raw materials and on a specific identification basis for work-in-process and finished goods. We value inventory at the lower of cost or net realizable value, and we write down defective or excess inventory to net realizable value based on historical experience or projected usage. We expense inventory related to our research and development activities as manufactured by us or when purchased.

As of March 31, 2024 and December 31, 2023, we recorded a provision of $2.4 and $2.0 million, respectively, for the net realizable value of our batches. Our manufacturing agreement with UCB Pharma (UCB) provides for a fixed selling price which we had negotiated in exchange for a higher royalty rate. Accordingly, when evaluating the net realizable value of our inventory for UCB, we include the negotiated increase of the royalties in our analysis, and the aggregate revenue has historically been greater than our manufacturing cost. Due to the decreases in the royalty rate for 2024 and 2025 as a result of a settlement agreement with UCB, the aggregate revenue is expected to be less than our manufacturing cost, and therefore we recorded a provision for net realizable value.

Other Current Assets

Other current assets consist of the following (in thousands):

	March 31, 2024		December 31, 2023
Prepaid research and development expenses	$	4,767	$	4,325
Non-trade receivables and other		1,816		1,047
Other prepaid expenses		4,160		4,407
Total other current assets	$	10,743	$	9,779

Accrued Expenses

Accrued expenses consist of the following (in thousands):

	March 31, 2024		December 31, 2023
Accrued compensation	$	7,384	$	5,553
Accrued clinical trial expenses		4,233		4,321
Liability to collaboration partners		1,310		2,678
Accrued contract termination costs		3,043		3,020
Other accrued expenses		8,311		6,590
Total accrued expenses	$	24,281	$	22,162

Liabilities Related to the Sales of Future Royalties

In 2012 and 2020, we sold to RPI Finance Trust (RPI) and HCR, respectively, our rights to receive royalties under our license and manufacturing agreements with certain pharmaceutical partners under the 2012 Purchase and Sale Agreement and the 2020 Purchase and Sale Agreement, respectively. We account for these transactions as debt and recognize non-cash royalty revenue and non-cash interest expense to amortize the proceeds over the lives of the respective arrangements. We periodically update our prospective non-cash interest rate based on our estimates of future royalties. As of March 31, 2024, our imputed interest rates for the arrangements with RPI and HCR were 30% and 19%, respectively.

The original 2020 Purchase and Sale Agreement was to expire -- and wherein the right to receive royalties would revert to us -- if HCR received aggregate royalties of $210.0 million on or prior to December 31, 2025 (the 2025 Threshold), or, if the 2025 Threshold was not achieved by December 31, 2025, when HCR received aggregate royalties of $240.0 million. On March 4, 2024, Nektar and HCR amended the original 2020 Purchase and Sale Agreement (the Amendment), pursuant to which the parties agreed to remove our reversionary rights in the royalties in exchange for a $15.0 million payment from HCR. Accordingly, HCR will receive all future royalties of the products, and none of these royalties will return to Nektar. We concluded that we should account for the Amendment as a modification of the existing arrangement, and therefore recorded the $15.0 million proceeds as an increase to the liability. We included the effects of the Amendment in determining our imputed interest rate of 19% as of March 31, 2024.

The following is a reconciliation of the changes in our liabilities related to the sales of future royalties for the three months ended March 31, 2024 (in thousands):

	Three Months Ended March 31, 2024
	2012 Purchase and Sale Agreement			2020 Purchase and Sale Agreement			Total
Liabilities related to the sales of future royalties, net – beginning balance	$	24,217		$	88,408		$	112,625
Non-cash royalty revenue		(6,944	)		(8,564	)		(15,508	)
Non-cash interest expense		1,831			3,700			5,531
Amortization of transaction costs		—			209			209
Proceeds from the Amendment		—			15,000			15,000
Liabilities related to the sales of future royalties, net – ending balance	$	19,104		$	98,753		$	117,857

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Commitments and Contingencies

3 Months Ended

Mar. 31, 2024

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

Note 4 — Commitments and Contingencies

Legal Matters

From time to time, we are involved in lawsuits, arbitrations, claims, investigations and proceedings, consisting of intellectual property, commercial, employment and other matters, which arise in the ordinary course of business. We make provisions for liabilities when it is both probable that a liability has been incurred and the amount of the loss can be reasonably estimated. Such provisions are reviewed at each reporting date and adjusted to reflect the impact of settlement negotiations, judicial and administrative rulings, advice of legal counsel, and other information and events pertaining to a particular case. Litigation is inherently unpredictable. If any unfavorable ruling were to occur in any specific period, there exists the possibility of a material adverse impact on the results of our operations for that period and on our cash flows and liquidity.

On August 7, 2023, we filed a complaint in the United States District Court for the Northern District of California (the Court) against Lilly alleging, among other claims, breach of contract and breach of implied covenant of good faith and fair dealing (the Complaint), in connection with our collaboration with Lilly. Following the denial of its motion to dismiss the Complaint entirely, Lilly filed an answer that included counterclaims against us alleging breach of specified confidentiality provisions and defamation. The case is proceeding.

We have recorded no liability for any litigation matters in our Condensed Consolidated Balance Sheets at either March 31, 2024 or December 31, 2023.

Indemnifications in Connection with Commercial Agreements

As part of our collaboration agreements with our partners related to the license, development, manufacture and supply of drugs and PEGylation materials based on our proprietary technologies and drug candidates, we generally agree to defend, indemnify and hold harmless our partners from and against third party liabilities arising out of the agreement, including product liability (with respect to our activities) and infringement of intellectual property to the extent the intellectual property is developed by us and licensed to our partners. The term of these indemnification obligations is generally perpetual commencing after execution of the agreement. There is generally no limitation on the potential amount of future payments we could be required to make under these indemnification obligations.

From time to time, we enter into other strategic agreements such as divestitures and financing transactions pursuant to which we are required to make representations and warranties and undertake to perform or comply with certain covenants. For example, we made certain intellectual property representations in connection with our RPI and HCR transactions, however, the time limitation we have to indemnify RPI with respect to any breach of these intellectual property-based representations and warranties has passed. In the event it is determined that we breached certain of the representations and warranties or covenants made by us in any such agreements or certain express indemnification provisions are applicable, we could incur substantial indemnification liabilities depending on the timing, nature, and amount of any such claims.

To date, we have not incurred any costs to defend lawsuits or settle claims related to these indemnification obligations, nor any breaches of representations or warranties or covenants. Because the aggregate amount of any potential indemnification obligation is not a stated amount, we cannot reasonably estimate the overall maximum amount of any such obligations.

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Pre-Funded Warrant

3 Months Ended

Mar. 31, 2024

Equity [Abstract]

Pre-Funded Warrant

Note 5 — Pre-Funded Warrant

In March 2024, we issued a pre-funded warrant to purchase an aggregate of 25,000,000 shares of our common stock to TCG at a price of $1.20 per share for gross proceeds of $30.0 million. Transaction costs were immaterial. The pre-funded warrant has an exercise price of $0.0001 per share and may be exercised at any time after the original issuance date. TCG may not exercise the warrant if TCG, together with its affiliates, would beneficially own more than 9.99% of the number of shares of our common stock outstanding immediately after giving effect to such exercise. TCG may increase or decrease this percentage not in

excess of 19.99% by providing at least 61 days’ prior notice to the Company. As of March 31, 2024, the warrant has not been exercised.

We classified the pre-funded warrant as a component of permanent equity in our Condensed Consolidated Balance Sheets as it is a freestanding financial instrument that was immediately exercisable, does not embody an obligation for the Company to repurchase its own shares and permits the holder to receive a fixed number of shares of common stock upon exercise. All of the shares underlying the pre-funded warrant have been included in the weighted-average number of shares of common stock used to calculate net loss per share attributable to common stockholders because the shares may be issued for little or no consideration, are fully vested and are exercisable after the original issuance date of the pre-funded warrant.

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License and Collaboration Agreements

3 Months Ended

Mar. 31, 2024

License And Collaboration Agreements [Abstract]

License and Collaboration Agreements

Note 6 — License and Collaboration Agreements

We have entered into various collaboration agreements including license agreements and collaborative research, development and commercialization agreements with various pharmaceutical and biotechnology companies. Under these collaboration arrangements, we are entitled to receive license fees, upfront payments, milestone and other contingent payments, royalties, sales milestone payments, and payments for the manufacture and supply of our proprietary PEGylation materials and/or reimbursement for research and development activities. We generally include our costs of performing these services in research and development expense, except for costs for product sales to our collaboration partners which we include in cost of goods sold. We analyze our agreements to determine whether we should account for the agreements within the scope of ASC 808 Collaborative Arrangements, and, if so, we analyze whether we should account for any elements under ASC 606 Revenue from Contracts with Customers.

Eli Lilly and Company (Lilly): Rezpegaldesleukin (previously referred to as NKTR-358)

On July 23, 2017, we entered into a worldwide license agreement (the Lilly Agreement) with Lilly to co-develop rezpegaldesleukin, a novel immunological drug candidate that we invented, pursuant to which we received an initial payment of $150.0 million and were eligible for up to $250.0 million in additional development and regulatory milestones. The Lilly Agreement provided that, during Phase 1B and Phase 2 development, we shared development costs wherein 75% of the costs were borne by Lilly and 25% of the costs were borne by us.

On April 23, 2023, we received from Lilly a notice of at-will termination of the Lilly Agreement. We have regained full rights to rezpegaldesleukin from Lilly, and the Lilly Agreement subsequently terminated. Following the return of our rights to develop rezpegaldesleukin, we bear all costs of development. We initiated a Phase 2b study of rezpegaldesleukin in patients with moderate-to-severe atopic dermatitis in October 2023 and a Phase 2b study of rezpegaldesleukin in patients with severe-to-very severe alopecia areata in March 2024. We will also explore other auto-immune indications for the development of rezpegaldesleukin.

Bristol-Myers Squibb Company (BMS): Bempegaldesleukin, also referred to as NKTR-214

Effective April 3, 2018, we entered into a Strategic Collaboration Agreement (the BMS Collaboration Agreement) and a Share Purchase Agreement with BMS. Pursuant to the BMS Collaboration Agreement, we and BMS jointly developed bempegaldesleukin in combination with BMS’ Opdivo®. The parties shared the internal and external development costs for bempegaldesleukin in combination regimens based on each party’s relative ownership interest in the compounds included in the regimens.

Upon the effective date of the BMS Collaboration Agreement in April 2018, BMS paid us a non-refundable upfront cash payment of $1.0 billion and purchased 8,284,600 shares of our common stock pursuant to the Share Purchase Agreement for total additional cash consideration of $850.0 million. In 2020, we received additional non-refundable milestone payments of $50.0 million.

In April 2022, we announced that BMS and we decided to discontinue all development of bempegaldesleukin in combination with Opdivo®. On September 6, 2023, BMS and we terminated the BMS Collaboration Agreement, and pursuant to the surviving provisions of the BMS Collaboration Agreement, we and BMS continue our efforts to wind down the

bempegaldesleukin program, and the cost sharing provisions continue to remain in effect as the parties wind down the studies. On February 12, 2024, we repurchased the 8.3 million shares previously sold to BMS for total cash consideration of $3.0 million.

We determined that the BMS Collaboration Agreement falls within the scope of ASC 808. Based on the cost sharing percentages described above, we recognize the net reimbursement to (from) BMS as an increase (decrease) to the applicable expense. As discussed in Note 7, beginning in the second quarter of 2022, we began reporting clinical trial, other third-party costs and employee costs for the wind down of the bempegaldesleukin program in restructuring, impairment and costs of terminated program. For the three months ended March 31, 2024, such amounts are immaterial and are included in research and development expense.

Other

We have other collaboration agreements that have resulted in commercialized products for our collaborations partners. Under these agreements, we may sell our proprietary PEGylation materials for use in these products, and we are entitled to receive royalties based on net sales of these products as well as sales milestones. As discussed in Note 3, we have sold our rights to receive royalties from these other collaboration agreements. Our non-cash royalty revenue, which totaled $16.9 million for the three months ended March 31, 2023, and totaled $15.5 million for the three months ended March 31, 2024, represents revenue for granting licenses which we had satisfied in prior periods.

Additionally, we have a collaboration agreement for a product under development, under which we are entitled to up to a total of $40.0 million of regulatory milestones, as well as royalties based on net sales of commercialized products, if any. However, given the current phase of development of the potential product under this collaboration agreement, we cannot estimate the probability or timing of achieving these milestones, and, therefore, have excluded all development milestones from the transaction price for this agreement.

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Restructuring, Impairment and Costs of Terminated Program, and Impairment of Goodwill

3 Months Ended

Mar. 31, 2024

Restructuring and Related Activities [Abstract]

Restructuring, Impairment and Costs of Terminated Program, and Impairment of Goodwill

Note 7 — Restructuring, Impairment and Costs of Terminated Program, and Impairment of Goodwill

Restructuring, Impairment and Costs of Terminated Program

In connection with our 2022 and 2023 Restructuring Plans, we report the following costs in restructuring, impairment and costs of terminated program:

•Clinical trial expense, other third-party costs and employee costs for the wind down of the bempegaldesleukin program, net of the reimbursement from BMS, initiated in 2022;

•Severance and related benefit costs pursuant to the 2022 and 2023 Restructuring Plans;

•Non-cash impairment of right-of-use assets and property, plant and equipment; and

•Contract termination and other costs associated with these plans.

Restructuring, impairment and costs of terminated program includes the following (in thousands):

	Three Months Ended March 31,
	2024		2023
Clinical trial expense, other third-party and employee costs for the wind down of the bempegaldesleukin program	$	—	$	1,598
Severance and benefit expense		—		5,483
Impairment of right-of-use assets and property, plant and equipment		—		13,200
Contract termination and other restructuring costs		975		912
Restructuring, impairment and other costs of terminated program	$	975	$	21,193

Wind Down of the Bempegaldesleukin Program

In prior periods through March 31, 2022, we reported the clinical trial costs, other third-party costs and employee costs related to the bempegaldesleukin program primarily in research and development expense. Beginning in the second quarter of

2022, following our announcement to terminate the program, we began reporting clinical trial, other third-party costs and employee costs for the wind down of the bempegaldesleukin program in restructuring, impairment and costs of terminated program. For the three months ended March 31, 2024, such amounts are immaterial and are included in research and development expense.

Severance and Benefit Expense

Employees affected by the reduction in force under the 2022 and 2023 Restructuring Plans are entitled to receive severance payments and certain Company funded benefits. The restructuring charges are recorded at fair value.

For the 2022 Restructuring Plan, we recognized all expense in 2022 and paid the final liability of $3.3 million in the three months ended March 31, 2023.

For the 2023 Restructuring Plan, we recognized a liability of $5.5 million of severance and benefit expense as of March 31, 2023, reflecting severance and benefits which the employees had vested into and for which payment was probable and reasonably estimable as of March 31, 2023. We recognized $7.9 million in total expense in 2023 for the 2023 Restructuring Plan and paid the final liability of $0.2 million in the three months ended March 31, 2024.

We do not expect to recognize any additional severance and benefits expense for the 2022 and 2023 Restructuring Plans.

The following table provides details regarding the severance and benefit expense for the three months ended March 31, 2024 pursuant to the 2023 Restructuring Plan and a reconciliation of the severance and benefits liability for the three months ended March 31, 2023 pursuant to the 2022 and 2023 Restructuring Plans, which we report within accrued expenses on our Condensed Consolidated Balance Sheet (in thousands):

	Three Months Ended March 31, 2023
	2023 Restructuring Plan			2022 Restructuring Plan			Total
Liability balance as of December 31, 2022	$	—		$	3,299		$	3,299
Expense recognized during the period		5,483			—			5,483
Payments during the period		—			(3,299	)		(3,299	)
Liability balance as of March 31, 2023	$	5,483		$	—		$	5,483
	Three Months Ended March 31, 2024
	2023 Restructuring Plan			2022 Restructuring Plan			Total
Liability balance as of December 31, 2023	$	196		$	—		$	196
Expense recognized during the period		—			—			—
Payments during the period		(196	)		—			(196	)
Liability balance as of March 31, 2024	$	—		$	—		$	—

Impairment of Long-Lived Assets

As a result of our 2022 and 2023 Restructuring Plans, we decided to seek a sublease for all of our leased spaces on Third Street and Mission Bay Blvd. South. Accordingly, we evaluate each space for impairment when management decides to sublease the respective space and at each reporting date thereafter, as facts and circumstances change. The significant assumptions in our impairment analysis relate to sublease income, including the length of time to enter into a sublease, sublease rental payments, free rent periods, tenant improvement allowances and broker commissions. When available, we use sublease negotiations or agreements, but in the absence of such information, we develop our own subjective estimates based on current real estate trends and market conditions. Accordingly, our estimates are subject to significant risk, and the terms of sublease agreements, if any, and the resulting amount and timing of sublease income, if ever realized, may be materially different than our estimates.

As part of our evaluation of each sublease space, we separately compare the estimated undiscounted sublease income, as described above, for each sublease to the net book value of the related long-term assets, which include right-of-use assets and

certain property, plant and equipment, primarily for leasehold improvements (collectively, sublease assets). If such sublease income exceeds the net book value of the sublease assets, we do not record an impairment charge. Otherwise, we record an impairment charge by reducing the net book value of the sublease assets to their estimated fair value, which we determined by discounting the estimated sublease income using the estimated borrowing rate of a market participant subtenant, which we estimated to be 7.9%, for the three months ended March 31, 2023.

During the three months ended March 31, 2023, we recorded an impairment charge for our remaining office and laboratory leased space in our Mission Bay Blvd. South facility which we decided to sublease under the 2023 Restructuring Plan. We also recorded impairment charges for certain excess laboratory equipment which we subsequently sold in 2023.

During the three months ended March 31, 2024, while we continue to seek subleases for our office lease space on Third. St. and our office and laboratory lease space on Mission Bay Blvd. South, we recorded no impairment charges during the three months ended March 31, 2024.

The following is a reconciliation of the impairment charges we recorded for the three months ended March 31, 2023, including the net book values of the sublease assets before the impairment and the fair values of the sublease assets (in thousands):

	Three Months Ended March 31, 2023
	Property, Plant and Equipment			Operating Lease Right-of-Use Assets			Total
Net book value of impaired facilities before write-off	$	5,114		$	28,434		$	33,548
Less: Fair value of impaired facilities — Level 3 of Fair Value Hierarchy		(3,314	)		(18,734	)		(22,048	)
Impairment expense for facilities		1,800			9,700			11,500
Impairment of other property, plant and equipment		1,700			—			1,700
Total impairment of right-of-use assets and property, plant and equipment	$	3,500		$	9,700		$	13,200

Contract Termination and Other Costs

We have incurred significant contract termination costs in connection with our 2022 Restructuring Plan. Because we adjust this liability at fair value at each reporting date, we continue to recognize expense as our estimates change until settlement.

The following are reconciliations of the contract termination and other costs for the 2022 Restructuring Plan for the three months ended March 31, 2024 and 2023. We report $3.0 million within accrued expenses and the remaining within other long-term liabilities on our Condensed Consolidated Balance Sheets as of March 31, 2024 and December 31, 2023.

	For the Three Months Ended March 31,
	2024			2023
Liability balances as of December 31, 2023 and December 31, 2022, respectively	$	5,542		$	7,710
Expense recognized during the period		975			878
Payments during the period		(928	)		(1,095	)
Liability balances as of March 31, 2024 and March 31, 2023, respectively	$	5,589		$	7,493

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Impairment of Goodwill

3 Months Ended

Mar. 31, 2024

Goodwill and Intangible Assets Disclosure [Abstract]

Impairment of Goodwill

Note 8 — Impairment of Goodwill

During the three months ended March 31, 2023, our stock price and resulting market capitalization experienced a significant, sustained decline. Accordingly, we assessed our long-lived assets, including our property, plant and equipment, right-of-use assets and goodwill, for impairment.

As part of our long-lived asset impairment analysis, we first assessed which long-lived assets have identifiable cash flows that are largely independent of the cash flows of other groups of assets. We concluded that the sublease assets, for which we recognized significant impairment charges during 2022 and 2023, including for the three months ended March 31, 2023, are

independent of our entity-wide group. See Note 7 for additional information regarding impairment charges that we have recorded for our sublease assets, as well as certain property, plant and equipment that we subsequently sold.

We next evaluated our remaining long-lived assets for impairment and performed a recoverability test using the undiscounted cash flows approach. We did not recognize any additional impairment charges on the remaining long-lived assets.

Finally, we measured the fair value of our reporting unit utilizing both income and market approaches for our entity-wide asset impairment analysis. Based on this analysis, we wrote off all of our goodwill, resulting in a non-cash impairment charge of $76.5 million which we reported as impairment of goodwill in our Condensed Consolidated Statements of Operations for the three months ended March 31, 2023. We had previously recognized goodwill primarily from our acquisitions of Shearwater Corp. and Aerogen, Inc. in 2001 and 2005, respectively.

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Stock-Based Compensation

3 Months Ended

Mar. 31, 2024

Share-Based Payment Arrangement [Abstract]

Stock-Based Compensation

Note 9 — Stock-Based Compensation

We recognized total stock-based compensation expense in our Condensed Consolidated Statements of Operations as follows (in thousands):

	Three Months Ended March 31,
	2024		2023
Cost of goods sold	$	633	$	812
Research and development		2,280		4,146
General and administrative		3,087		5,061
Total stock-based compensation	$	6,000	$	10,019

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Organization and Summary of Significant Accounting Policies (Policies)

3 Months Ended

Mar. 31, 2024

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Organization

Organization

We are a clinical stage, research-based drug discovery biopharmaceutical company headquartered in San Francisco, California and incorporated in Delaware, focused on discovering and developing innovative medicines in the field of immunotherapy. Within this growing field, we direct our efforts toward creating new immunomodulatory agents that selectively induce, amplify, attenuate or prevent immune responses in order to achieve desired therapeutic outcomes. Our pipeline of clinical-stage and preclinical-stage immunomodulatory agents targets the treatment of autoimmune diseases (e.g. rezpegaldesleukin and NKTR-0165, respectively) and cancer (e.g. NKTR-255).

Our research and development activities have required significant ongoing investment to date and are expected to continue to require significant investment. As a result, we expect to continue to incur substantial losses and negative cash flows from operations in the future. We have financed our operations primarily through cash generated from licensing, collaboration and manufacturing agreements and financing transactions. As of March 31, 2024, we had approximately $326.0 million in cash and investments in marketable securities.

Financing Transactions

Financing Transactions

During the three months ended March 31, 2024, we entered into the following transactions:

•On February 12, 2024, for total cash consideration paid of $3.0 million, we repurchased from Bristol Myers Squibb Company (BMS) 8.3 million shares of Nektar's common stock that were previously sold to BMS, which we report as treasury stock on our Condensed Consolidated Balance Sheets. See Note 6 for additional information.

•On March 4, 2024, we entered into a Securities Purchase Agreement with TCG Crossover Fund II, L.P. (TCG), pursuant to which we issued a pre-funded warrant to TCG to purchase 25,000,000 shares of Nektar’s common stock for gross proceeds of $30.0 million (or a purchase price of $1.20 per share of common stock that can be issued upon exercise of the pre-funded warrant). See Note 5 for additional information.

•On March 4, 2024, for total cash consideration received of $15.0 million, we entered into an amendment (the Amendment) with entities managed by Healthcare Royalty Management, LLC (collectively, HCR) to remove the cap on royalties previously sold to HCR under a Purchase and Sale Agreement (the 2020 Purchase and Sale Agreement). See Note 3 for additional information.

Restructuring Plans

Restructuring Plans

In April 2022, we announced the termination of the bempegaldesleukin program and a new strategic reorganization and cost restructuring plan (together, the 2022 Restructuring Plan), pursuant to which we completed an approximate 70% reduction of our workforce during 2022. We also decided to seek a sublease for certain of our leased premises in San Francisco, CA, including all of our office leased space on Third St. and portions of our office and laboratory space on Mission Bay Blvd. South.

In April 2023, we announced Eli Lilly and Company's (Lilly) decision to terminate our license agreement (the Lilly Agreement) for the development of rezpegaldesleukin, as well as a new strategic reprioritization and cost restructuring plan (the 2023 Restructuring Plan). Under the 2023 Restructuring Plan, we reduced our San Francisco-based workforce by approximately 60%. In addition, under the 2023 Restructuring Plan, we decided to seek a sublease for our remaining office and laboratory space on Mission Bay Blvd. South which we had not planned to sublease pursuant to the 2022 Restructuring Plan.

We have regained full rights to rezpegaldesleukin from Lilly, and we initiated a Phase 2b study of rezpegaldesleukin in patients with moderate-to-severe atopic dermatitis in October 2023 and a Phase 2b study of rezpegaldesleukin in patients with severe-to-very severe alopecia areata in March 2024. We will also explore other auto-immune indications for the development of rezpegaldesleukin.

We have incurred significant costs resulting from the 2022 and 2023 Restructuring Plans. See Note 7 for additional information on the effect on our Condensed Consolidated Financial Statements.

Basis of Presentation and Principles of Consolidation

Basis of Presentation and Principles of Consolidation

Our Condensed Consolidated Financial Statements include the financial position, results of operations and cash flows of Nektar Therapeutics and our wholly-owned subsidiaries. We have eliminated all intercompany accounts and transactions in consolidation.

We prepared our Condensed Consolidated Financial Statements following the requirements of the Securities and Exchange Commission (SEC) for interim reporting. As permitted under those rules, we may condense or omit certain footnotes or other financial information that are normally required by U.S. generally accepted accounting principles (GAAP) for annual periods. In the opinion of management, these financial statements include all normal and recurring adjustments that we consider necessary for the fair presentation of our financial position and operating results.

Our Condensed Consolidated Financial Statements are denominated in U.S. dollars. Accordingly, changes in exchange rates between the applicable foreign currency and the U.S. dollar will affect the translation of each foreign subsidiary’s financial results into U.S. dollars for purposes of reporting our consolidated financial results. We include translation gains and losses in accumulated other comprehensive loss in the stockholders’ equity section of our Condensed Consolidated Balance Sheets.

Our comprehensive loss consists of our net loss plus our foreign currency translation gains and losses and unrealized gains and losses on available-for-sale securities. There were no significant reclassifications out of accumulated other comprehensive income (loss) to the statements of operations during the three months ended March 31, 2024 and 2023.

The accompanying Condensed Consolidated Financial Statements are unaudited. The Condensed Consolidated Balance Sheet data as of December 31, 2023 was derived from the audited consolidated financial statements which are included in our Annual Report on Form 10-K for the year ended December 31, 2023 filed with the SEC on March 5, 2024. The information included in this Quarterly Report on Form 10-Q should be read in conjunction with the consolidated financial statements and the accompanying notes to those financial statements.

Revenue, expenses, assets, and liabilities can vary during each quarter of the year. The results and trends in these interim Condensed Consolidated Financial Statements are not necessarily indicative of the results to be expected for the full year or any other period.

Use of Estimates

Use of Estimates

The preparation of consolidated financial statements in conformity with U.S. generally accepted accounting principles (GAAP) requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenue and expenses during the reporting period. Accounting estimates and assumptions are inherently uncertain.

Actual results could differ materially from those estimates and assumptions. As appropriate, we assess estimates each period, update them to reflect current information, and generally reflect any changes in estimates in the period first identified.

Significant Concentrations

Significant Concentrations

Our customers are primarily pharmaceutical companies that are located in the U.S. and Europe and with whom we have multi-year arrangements. Our accounts receivable balance contains billed and unbilled trade receivables from product sales, milestones (to the extent that they have been achieved and are due from the counterparty), and other contingent payments, as well as reimbursable costs from collaborative research and development agreements. We generally do not require collateral from our

customers. We perform a regular review of our customers’ credit risk and payment histories, including payments made after period end. Historically, we have not experienced credit losses from our accounts receivable. We have not recorded reserves for credit losses for the three months ended March 31, 2024 and 2023, nor have recorded such an allowance as of March 31, 2024 or December 31, 2023.

We are dependent on our suppliers and contract manufacturers to provide raw materials and drugs of appropriate quality and reliability and to meet applicable contract and regulatory requirements. In certain cases, we rely on single sources of supply of one or more critical materials. Consequently, in the event that supplies are delayed or interrupted for any reason, our ability to develop and produce our drug candidates or our ability to meet our supply obligations could be significantly impaired, which could have a material adverse effect on our business, financial condition and results of operations.

For our available-for-sale securities, we have significant concentrations of issuers in the banking and financial services industries. While our investment policy requires that we only invest in highly-rated securities and limit our exposure to any single issuer, various factors may materially affect the financial condition of issuers. Additionally, pursuant to our investment policy, we may sell securities before maturity if the issuer’s credit rating has been downgraded below our minimum credit rating requirements, which may result in a loss on the sale. Accordingly, if various factors result in downgrades below our minimum credit rating requirements and if we decide to sell these securities, we may experience losses on such sales.

Treasury Stock

Treasury Stock

We record treasury stock activities under the cost method. Treasury stock is included in authorized and issued shares but excluded from outstanding shares. The re-issuance of treasury stock is accounted for on a first in, first-out basis and any differences between the cost of treasury stock and the re-issuance proceeds are charged or credited to additional paid-in capital.

Restructuring

Restructuring

We recognize restructuring charges related to reorganization plans that have been committed to by management when liabilities have been incurred. In connection with these activities, we record restructuring charges at fair value for:

•contractual or other employee termination benefits provided that the obligations result from services already rendered based on rights that vest or accumulated when the payment of benefits becomes probable and the amount can be reasonably estimated,

•one-time employee termination benefits on the communication date from management to the employees provided that management has committed to a plan of termination, the plan identifies the employees and their expected termination dates, the details of termination benefits are complete, and it is unlikely that changes to the plan will be made or the plan will be withdrawn,

•contract termination costs when we cancel the contract in accordance with its terms, and

•costs to be incurred over the remaining contract term without economic benefit to us at the cease-use date.

For one-time employee terminations benefits, we recognize the liability in full on the communication date when future services are not required or amortize the liability ratably over the service period, if required. The fair value of termination benefits reflects our estimates of expected utilization of certain Company-funded post-employment benefits.

See Note 7 for additional information on the severance expense that we recognized for employees terminated in connection with our reductions-in-force.

Impairment of Goodwill

Impairment of Goodwill

Goodwill is assessed for impairment on an annual basis and whenever events and circumstances indicate that it may be impaired. Factors that may indicate potential impairment and trigger an impairment test include, but are not limited to, current economic, market and geopolitical conditions, including a significant, sustained decline in our stock price and market

capitalization compared to the net book value; an adverse change in legal factors, business climate or operational performance of the business; or significant changes in the ability of the reporting unit to generate positive cash flows for our strategic business objectives. If the carrying value of the reporting unit, including goodwill, exceeds the reporting unit’s fair value, we will recognize a goodwill impairment loss, and we will write down goodwill such that the carrying value of the reporting unit equals its fair value, provided that we cannot reduce goodwill below zero.

See Note 8 for additional information regarding the impairment charges we recorded during the three months ended March 31, 2023 in connection with our goodwill.

Long-Lived Asset Impairment

Long-Lived Asset Impairment

We assess the impairment of long-lived assets whenever events or changes in business circumstances indicate that the carrying amounts of the assets may not be fully recoverable. In the case of property, plant and equipment and right-of-use assets for our leases, we determine whether there has been an impairment by comparing the carrying value of the asset to the anticipated undiscounted net cash flows associated with the asset. If such cash flows are less than the carrying value, we write down the asset to its fair value, which may be measured as anticipated net cash flows associated with the asset, discounted at a rate that we believe a market participant would utilize to reflect the risks associated with the cash flows, such as credit risk.

See Note 7 for additional information regarding the impairment charges we recorded in connection with our leased facilities and certain property and equipment.

Net Loss per Share

Net Loss per Share

For all periods presented in the Condensed Consolidated Statements of Operations, the net loss available to common stockholders is equal to the reported net loss. We calculate basic net loss per share based on the weighted-average number of common shares outstanding, including the pre-funded warrant, during the periods presented. Shares of common stock into which the pre-funded warrant may be exercised are considered outstanding for the purposes of computing basic net loss per share because the shares may be issued for little or no consideration, are fully vested and are exercisable after the original issuance date. For the three months ended March 31, 2024 and 2023, basic and diluted net loss per share are the same due to our net losses and the requirement to exclude potentially dilutive securities which would have an antidilutive effect on net loss per share. We excluded shares underlying the weighted average outstanding stock options, restricted stock units (RSUs) and performance stock units (PSUs), as follows (in thousands):

	Three Months Ended March 31,
	2024		2023
Potentially dilutive securities		26,973		22,798

Inventory

We value inventory at the lower of cost or net realizable value, and we write down defective or excess inventory to net realizable value based on historical experience or projected usage. We expense inventory related to our research and development activities as manufactured by us or when purchased.

As of March 31, 2024 and December 31, 2023, we recorded a provision of $2.4 and $2.0 million, respectively, for the net realizable value of our batches. Our manufacturing agreement with UCB Pharma (UCB) provides for a fixed selling price which we had negotiated in exchange for a higher royalty rate. Accordingly, when evaluating the net realizable value of our inventory for UCB, we include the negotiated increase of the royalties in our analysis, and the aggregate revenue has historically been greater than our manufacturing cost. Due to the decreases in the royalty rate for 2024 and 2025 as a result of a settlement agreement with UCB, the aggregate revenue is expected to be less than our manufacturing cost, and therefore we recorded a provision for net realizable value.

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Organization and Summary of Significant Accounting Policies (Tables)

3 Months Ended

Mar. 31, 2024

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share

We excluded shares underlying the weighted average outstanding stock options, restricted stock units (RSUs) and performance stock units (PSUs), as follows (in thousands):

	Three Months Ended March 31,
	2024		2023
Potentially dilutive securities		26,973		22,798

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Cash and Investments in Marketable Securities (Tables)

3 Months Ended

Mar. 31, 2024

Fair Value Disclosures [Abstract]

Schedule of Cash and Investments in Marketable Securities, Including Cash Equivalents

Cash and investments in marketable securities, including cash equivalents, are as follows (in thousands):

	Estimated Fair Value at
	March 31, 2024		December 31, 2023
Cash and cash equivalents	$	48,642	$	35,277
Short-term investments		240,596		268,339
Long-term investments		36,778		25,825
Total cash and investments in marketable securities	$	326,016	$	329,441

Schedule of Portfolio of Cash and Investments in Marketable Securities

Our portfolio of cash and investments in marketable securities includes (in thousands):

		March 31, 2024									December 31, 2023
	Fair Value Hierarchy Level	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses			Fair Value		Fair Value
Corporate notes and bonds	2	$	75,745	$	2	$	(163	)	$	75,584	$	38,882
Corporate commercial paper	2		211,955		—		(261	)		211,694		255,241
Obligations of U.S. government agencies	2		3,457		—		(3	)		3,454		—
Available-for-sale investments		$	291,157	$	2	$	(427	)	$	290,732	$	294,123
Money market funds	1									15,959		2,359
Certificates of deposit	2									13,898		15,116
Cash	N/A									5,427		17,843
Total cash and investments in marketable securities									$	326,016	$	329,441

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Condensed Consolidated Financial Statement Details (Tables)

3 Months Ended

Mar. 31, 2024

Inventory Disclosure [Abstract]

Schedule of Inventory

Inventory consists of the following (in thousands):

	March 31, 2024		December 31, 2023
Raw materials	$	1,936	$	1,861
Work-in-process		9,962		12,880
Finished goods		4,340		1,360
Total inventory, net	$	16,238	$	16,101

Schedule of Other Current Assets

Other current assets consist of the following (in thousands):

	March 31, 2024		December 31, 2023
Prepaid research and development expenses	$	4,767	$	4,325
Non-trade receivables and other		1,816		1,047
Other prepaid expenses		4,160		4,407
Total other current assets	$	10,743	$	9,779

Schedule of Accrued Expenses

Accrued expenses consist of the following (in thousands):

	March 31, 2024		December 31, 2023
Accrued compensation	$	7,384	$	5,553
Accrued clinical trial expenses		4,233		4,321
Liability to collaboration partners		1,310		2,678
Accrued contract termination costs		3,043		3,020
Other accrued expenses		8,311		6,590
Total accrued expenses	$	24,281	$	22,162

Schedule of Liability Related to Sale of Potential Future Royalties

The following is a reconciliation of the changes in our liabilities related to the sales of future royalties for the three months ended March 31, 2024 (in thousands):

	Three Months Ended March 31, 2024
	2012 Purchase and Sale Agreement			2020 Purchase and Sale Agreement			Total
Liabilities related to the sales of future royalties, net – beginning balance	$	24,217		$	88,408		$	112,625
Non-cash royalty revenue		(6,944	)		(8,564	)		(15,508	)
Non-cash interest expense		1,831			3,700			5,531
Amortization of transaction costs		—			209			209
Proceeds from the Amendment		—			15,000			15,000
Liabilities related to the sales of future royalties, net – ending balance	$	19,104		$	98,753		$	117,857

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Restructuring, Impairment and Costs of Terminated Program, and Impairment of Goodwill (Tables)

3 Months Ended

Mar. 31, 2024

Restructuring and Related Activities [Abstract]

Schedule of Restructuring, Impairment and Other Costs of Terminated Program

Restructuring, impairment and costs of terminated program includes the following (in thousands):

	Three Months Ended March 31,
	2024		2023
Clinical trial expense, other third-party and employee costs for the wind down of the bempegaldesleukin program	$	—	$	1,598
Severance and benefit expense		—		5,483
Impairment of right-of-use assets and property, plant and equipment		—		13,200
Contract termination and other restructuring costs		975		912
Restructuring, impairment and other costs of terminated program	$	975	$	21,193

The following table provides details regarding the severance and benefit expense for the three months ended March 31, 2024 pursuant to the 2023 Restructuring Plan and a reconciliation of the severance and benefits liability for the three months ended March 31, 2023 pursuant to the 2022 and 2023 Restructuring Plans, which we report within accrued expenses on our Condensed Consolidated Balance Sheet (in thousands):

	Three Months Ended March 31, 2023
	2023 Restructuring Plan			2022 Restructuring Plan			Total
Liability balance as of December 31, 2022	$	—		$	3,299		$	3,299
Expense recognized during the period		5,483			—			5,483
Payments during the period		—			(3,299	)		(3,299	)
Liability balance as of March 31, 2023	$	5,483		$	—		$	5,483
	Three Months Ended March 31, 2024
	2023 Restructuring Plan			2022 Restructuring Plan			Total
Liability balance as of December 31, 2023	$	196		$	—		$	196
Expense recognized during the period		—			—			—
Payments during the period		(196	)		—			(196	)
Liability balance as of March 31, 2024	$	—		$	—		$	—

The following is a reconciliation of the impairment charges we recorded for the three months ended March 31, 2023, including the net book values of the sublease assets before the impairment and the fair values of the sublease assets (in thousands):

	Three Months Ended March 31, 2023
	Property, Plant and Equipment			Operating Lease Right-of-Use Assets			Total
Net book value of impaired facilities before write-off	$	5,114		$	28,434		$	33,548
Less: Fair value of impaired facilities — Level 3 of Fair Value Hierarchy		(3,314	)		(18,734	)		(22,048	)
Impairment expense for facilities		1,800			9,700			11,500
Impairment of other property, plant and equipment		1,700			—			1,700
Total impairment of right-of-use assets and property, plant and equipment	$	3,500		$	9,700		$	13,200

The following are reconciliations of the contract termination and other costs for the 2022 Restructuring Plan for the three months ended March 31, 2024 and 2023. We report $3.0 million within accrued expenses and the remaining within other long-term liabilities on our Condensed Consolidated Balance Sheets as of March 31, 2024 and December 31, 2023.

	For the Three Months Ended March 31,
	2024			2023
Liability balances as of December 31, 2023 and December 31, 2022, respectively	$	5,542		$	7,710
Expense recognized during the period		975			878
Payments during the period		(928	)		(1,095	)
Liability balances as of March 31, 2024 and March 31, 2023, respectively	$	5,589		$	7,493

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Stock-Based Compensation (Tables)

3 Months Ended

Mar. 31, 2024

Share-Based Payment Arrangement [Abstract]

Schedule of Stock-Based Compensation Expense

We recognized total stock-based compensation expense in our Condensed Consolidated Statements of Operations as follows (in thousands):

	Three Months Ended March 31,
	2024		2023
Cost of goods sold	$	633	$	812
Research and development		2,280		4,146
General and administrative		3,087		5,061
Total stock-based compensation	$	6,000	$	10,019

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Organization and Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)			1 Months Ended			3 Months Ended
	Mar. 04, 2024	Feb. 12, 2024	Mar. 31, 2024	Jun. 30, 2023	Apr. 30, 2022	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Organization And Summary Of Significant Accounting Policies [Line Items]
Cash and investments in marketable securities			$ 326,016,000			$ 326,016,000		$ 329,441,000
Proceeds from issuance of pre-funded warrant						30,000,000	$ 0
Accounts receivable, credit loss expense (reversal)						$ 0	$ 0
Bristol Myers Squibb Company
Organization And Summary Of Significant Accounting Policies [Line Items]
Sale of stock repurchased cash consideration		$ 3,000,000
Sale of stock shares repurchased		8,300,000
Securities Purchase Agreement | TCG Crossover Fund II, L.P.
Organization And Summary Of Significant Accounting Policies [Line Items]
Proceeds from issuance of pre-funded warrant	$ 30,000,000		$ 30,000,000
2020 Purchase and Sale Agreement
Organization And Summary Of Significant Accounting Policies [Line Items]
Amount exchanged to remove cap on royalties	$ 15,000,000
Pre-Funded Warrant | Securities Purchase Agreement | TCG Crossover Fund II, L.P.
Organization And Summary Of Significant Accounting Policies [Line Items]
Number of warrants issued to be purchase common shares	25,000,000		25,000,000			25,000,000
Shares issued, price per share	$ 1.2		$ 1.2			$ 1.2
Employee Severance | 2022 Restructuring Plan
Organization And Summary Of Significant Accounting Policies [Line Items]
Workforce termination, percentage					70.00%
Employee Severance | 2023 Restructuring Plan
Organization And Summary Of Significant Accounting Policies [Line Items]
Workforce termination, percentage				60.00%

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Organization and Summary of Significant Accounting Policies - Weighted Average Outstanding Stock Options (Details) - shares shares in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Stock Options, RSUs And PSUs
Organization And Summary Of Significant Accounting Policies [Line Items]
Potentially dilutive securities (in shares)	26,973	22,798

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Cash and Investments in Marketable Securities - Cash and Investments in Marketable Securities, Including Cash Equivalents (Detail) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Estimated Fair Value at
Cash and cash equivalents	$ 48,642	$ 35,277
Short-term investments	240,596	268,339
Long-term investments	36,778	25,825
Total cash and investments in marketable securities	$ 326,016	$ 329,441

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Cash and Investments in Marketable Securities - Portfolio of Cash and Investments in Marketable Securities (Detail) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash	$ 5,427	$ 17,843
Total cash and investments in marketable securities	326,016	329,441
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	291,157
Gross Unrealized Gains	2
Gross Unrealized Losses	(427)
Fair Value	290,732	294,123
Level 2 | Corporate notes and bonds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	75,745
Gross Unrealized Gains	2
Gross Unrealized Losses	(163)
Fair Value	75,584	38,882
Level 2 | Corporate commercial paper
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	211,955
Gross Unrealized Gains	0
Gross Unrealized Losses	(261)
Fair Value	211,694	255,241
Level 2 | Obligations of U.S. government agencies
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Amortized Cost	3,457
Gross Unrealized Gains	0
Gross Unrealized Losses	(3)
Fair Value	3,454	0
Level 2 | Certificates of deposit
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure	13,898	15,116
Level 1 | Money market funds
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments, fair value disclosure	$ 15,959	$ 2,359

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Condensed Consolidated Financial Statement Details - Schedule of Inventory (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Inventory Disclosure [Abstract]
Raw materials	$ 1,936	$ 1,861
Work-in-process	9,962	12,880
Finished goods	4,340	1,360
Total inventory, net	$ 16,238	$ 16,101

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Condensed Consolidated Financial Statement Details - Schedule of Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	$ 17,475	$ 18,856

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Condensed Consolidated Financial Statement Details - Narrative (Details) $ in Thousands			3 Months Ended
	Mar. 04, 2024 USD ($)	Dec. 16, 2020 USD ($)	Mar. 31, 2024 USD ($)	Mar. 31, 2023 USD ($)	Dec. 31, 2023 USD ($)
Goodwill [Line Items]
Provision for inventory obsolescence			$ 1,006	$ 952
Impairment of other property, plant and equipment			0	13,200
Impairment of goodwill			$ 0	$ 76,501
2012 Purchase and Sale Agreement
Goodwill [Line Items]
Royalties liability discount rate			0.30
2020 Purchase and Sale Agreement
Goodwill [Line Items]
Royalties liability discount rate			0.19
Payment of transaction related to purchase and sale agreement		$ 210,000
Payment of transaction related to purchase and sale agreement if threshold is not achieved		$ 240,000
Amount exchanged to remove cap on royalties	$ 15,000
Proceeds from sale of royalty rights			$ 15,000
UCB Pharma Manufacturing Agreement
Goodwill [Line Items]
Net realizable value of assets			$ 2,400		$ 2,000

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Condensed Consolidated Financial Statement Details - Schedule of Goodwill (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Goodwill [Roll Forward]
Impairment of goodwill	$ 0	$ (76,501)

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Condensed Consolidated Financial Statement Details - Schedule of Other Current Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Other current assets	$ 10,743	$ 9,779
Prepaid research and development expenses
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Other current assets	4,767	4,325
Non-trade receivables and other
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Other current assets	1,816	1,047
Other prepaid expenses
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Other current assets	$ 4,160	$ 4,407

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Condensed Consolidated Financial Statement Details - Schedule of Accrued Expenses (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Inventory Disclosure [Abstract]
Accrued compensation	$ 7,384	$ 5,553
Accrued clinical trial expenses	4,233	4,321
Liability to collaboration partners	1,310	2,678
Accrued contract termination costs	3,043	3,020
Other accrued expenses	8,311	6,590
Total accrued expenses	$ 24,281	$ 22,162

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Condensed Consolidated Financial Statement Details - Schedule of Liability Related to Sale of Potential Future Royalties (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Liabilities related to the sales of future royalties, net – beginning balance	$ 112,625
Non-cash royalty revenue	(15,508)	$ (16,861)
Non-cash interest expense	5,531	$ 6,405
Amortization of transaction costs	209
Proceeds from the Amendment	15,000
Liabilities related to the sales of future royalties, net – ending balance	117,857
2012 Purchase and Sale Agreement
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Liabilities related to the sales of future royalties, net – beginning balance	24,217
Non-cash royalty revenue	(6,944)
Non-cash interest expense	1,831
Amortization of transaction costs	0
Proceeds from the Amendment	0
Liabilities related to the sales of future royalties, net – ending balance	19,104
2020 Purchase and Sale Agreement
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Liabilities related to the sales of future royalties, net – beginning balance	88,408
Non-cash royalty revenue	(8,564)
Non-cash interest expense	3,700
Amortization of transaction costs	209
Proceeds from the Amendment	15,000
Liabilities related to the sales of future royalties, net – ending balance	$ 98,753

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Commitments and Contingencies - Additional Information (Details) - USD ($)	Mar. 31, 2024	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Liability for litigation	$ 0	$ 0

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Pre-Funded Warrant - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended	3 Months Ended
	Mar. 04, 2024	Mar. 31, 2024	Mar. 31, 2024	Mar. 31, 2023
Subsidiary, Sale of Stock [Line Items]
Proceeds from issuance of pre-funded warrant			$ 30,000	$ 0
Pre-Funded Warrant
Subsidiary, Sale of Stock [Line Items]
Exercise price of warrants		$ 0.0001	$ 0.0001
Securities Purchase Agreement | TCG Crossover Fund II, L.P.
Subsidiary, Sale of Stock [Line Items]
Proceeds from issuance of pre-funded warrant	$ 30,000	$ 30,000
Warrant exercised prior notice period		61 days
Securities Purchase Agreement | TCG Crossover Fund II, L.P. | Maximum
Subsidiary, Sale of Stock [Line Items]
Percentage of number of shares of warrant exercised		19.99%
Securities Purchase Agreement | TCG Crossover Fund II, L.P. | Pre-Funded Warrant
Subsidiary, Sale of Stock [Line Items]
Number of warrants issued to be purchase common shares	25,000,000	25,000,000	25,000,000
Shares issued, price per share	$ 1.2	$ 1.2	$ 1.2
Affiliates | Securities Purchase Agreement | TCG Crossover Fund II, L.P. | Maximum
Subsidiary, Sale of Stock [Line Items]
Percentage of number of shares of warrant exercised		9.99%

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License and Collaboration Agreements - Additional Information (Details) - USD ($)			1 Months Ended	3 Months Ended
	Feb. 12, 2024	Jul. 23, 2017	Apr. 30, 2018	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2020
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue, excluding assessed tax				$ 21,639,000	$ 21,594,000
Non-cash royalty revenue related to the sales of future royalties
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Revenue, excluding assessed tax				15,508,000	$ 16,861,000
Bristol Myers Squibb Company
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Sale of stock shares repurchased	8,300,000
Sale of stock repurchased cash consideration	$ 3,000,000
Bristol Myers Squibb Company | Purchase Agreement
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Shares issued (in shares)			8,284,600
Sale of stock consideration received			$ 850,000,000
Other Partner
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Potential future additional payments for development milestones				$ 40,000,000
Nektar-358 | Eli Lilly
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Percentage of sharing in Phase 2 development costs		75.00%
Nektar-358 | Maximum | Eli Lilly And Company
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Potential future additional development and regulatory milestones (up to)		$ 250,000,000
Bristol Myers Squibb Collaboration Agreement
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Sale of stock shares repurchased	8,300,000
Sale of stock repurchased cash consideration	$ 3,000,000
Nektar's | Nektar-358
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Received upfront and milestone payment		$ 150,000,000
Percentage of sharing in Phase 2 development costs		25.00%
Nektar's | Bristol Myers Squibb Collaboration Agreement | Nektar 214
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Upfront and milestone payments received from license agreements			$ 1,000,000,000
Nektar's | Bristol Myers Squibb Collaboration Agreement | Nektar 214 | Milestone One
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Potential future additional payments for development milestones						$ 50,000,000

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Restructuring, Impairment and Costs of Terminated Program, and Impairment of Goodwill - Narrative (Details) - USD ($)	1 Months Ended		3 Months Ended		12 Months Ended
	Jun. 30, 2023	Apr. 30, 2022	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Restructuring Cost and Reserve [Line Items]
Non-cash impairment charges				$ 11,500,000
Contract termination and other restructuring costs			$ 975,000	912,000
Impairment of other property, plant and equipment				1,700,000
Impairment of goodwill			0	$ 76,501,000
Mission Bay Facility
Restructuring Cost and Reserve [Line Items]
Non-cash impairment charges			0
2022 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Contract termination and other costs included in accrued expenses			3,000,000		$ 3,000,000
Measurement Input, Market Participant Subtenant Borrowing Rate
Restructuring Cost and Reserve [Line Items]
Operating lease, measurement input				7.90%
Employee Severance
Restructuring Cost and Reserve [Line Items]
Restructuring, impairment, and costs of terminated program			0	$ 5,483,000
Payments during the period			196,000	3,299,000
Employee Severance | 2022 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Workforce termination, percentage		70.00%
Restructuring, impairment, and costs of terminated program			0	0
Payments during the period			0	3,299,000
Employee Severance | 2023 Restructuring Plan
Restructuring Cost and Reserve [Line Items]
Workforce termination, percentage	60.00%
Restructuring, impairment, and costs of terminated program			0	5,483,000	$ 7,900,000
Payments during the period			$ 196,000	$ 0

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Restructuring, Impairment and Costs of Terminated Program, and Impairment of Goodwill - Summary of Restructuring Costs (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Restructuring Cost and Reserve [Line Items]
Clinical trial expense, other third-party and employee costs for the wind down of the bempegaldesleukin program	$ 0	$ 1,598
Severance and benefit expense	0	5,483
Impairment of other property, plant and equipment	0	13,200
Contract termination and other restructuring costs	975	912
Restructuring, impairment and other costs of terminated program	$ 975	$ 21,193

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Restructuring, Impairment and Costs of Terminated Program, and Impairment of Goodwill - Non-cash Impairment Charges Pertaining 2022 Restructuring Plan (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2023 USD ($)
Restructuring Cost and Reserve [Line Items]
Total impairment of lease assets	$ (11,500)

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Restructuring, Impairment and Costs of Terminated Program, and Impairment of Goodwill - Restructuring Reserve Rollforward (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Employee Severance
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	$ 196	$ 3,299	$ 3,299
Expense recognized during the period	0	5,483
Payments during the period	(196)	(3,299)
Restructuring reserve, ending balance	0	5,483	196
Employee Severance | 2023 Restructuring Plan
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	196	0	0
Expense recognized during the period	0	5,483	7,900
Payments during the period	(196)	0
Restructuring reserve, ending balance	0	5,483	196
Employee Severance | 2022 Restructuring Plan
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	0	3,299	3,299
Expense recognized during the period	0	0
Payments during the period	0	(3,299)
Restructuring reserve, ending balance	0	0	0
Contract Termination and Other Costs | 2022 Restructuring Plan
Restructuring Reserve [Roll Forward]
Restructuring reserve, beginning balance	5,542	7,710	7,710
Expense recognized during the period	975	878
Payments during the period	(928)	(1,095)
Restructuring reserve, ending balance	$ 5,589	$ 7,493	$ 5,542

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Restructuring, Impairment and Costs of Terminated Program, and Impairment of Goodwill - Sublease Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Restructuring Cost and Reserve [Line Items]
Impairment expense for facilities		$ 11,500
Impairment of other property, plant and equipment		1,700
Total impairment of right-of-use assets and property, plant and equipment	$ 0	13,200
Reported Value Measurement
Restructuring Cost and Reserve [Line Items]
Property, plant and equipment and operating lease right-of-use assets		33,548
Property, Plant and Equipment
Restructuring Cost and Reserve [Line Items]
Impairment expense for facilities		1,800
Impairment of other property, plant and equipment		1,700
Total impairment of right-of-use assets and property, plant and equipment		3,500
Property, Plant and Equipment | Reported Value Measurement
Restructuring Cost and Reserve [Line Items]
Property, plant and equipment and operating lease right-of-use assets		5,114
Operating Lease Right-of-Use Assets
Restructuring Cost and Reserve [Line Items]
Impairment expense for facilities		9,700
Impairment of other property, plant and equipment		0
Total impairment of right-of-use assets and property, plant and equipment		9,700
Operating Lease Right-of-Use Assets | Reported Value Measurement
Restructuring Cost and Reserve [Line Items]
Property, plant and equipment and operating lease right-of-use assets		28,434
Fair Value, Level 3 | Estimate of Fair Value Measurement
Restructuring Cost and Reserve [Line Items]
Property, plant and equipment and operating lease right-of-use assets		(22,048)
Fair Value, Level 3 | Property, Plant and Equipment | Estimate of Fair Value Measurement
Restructuring Cost and Reserve [Line Items]
Property, plant and equipment and operating lease right-of-use assets		(3,314)
Fair Value, Level 3 | Operating Lease Right-of-Use Assets | Estimate of Fair Value Measurement
Restructuring Cost and Reserve [Line Items]
Property, plant and equipment and operating lease right-of-use assets		$ (18,734)

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Impairement of Goodwill (Additional Information) (Details) - USD ($)	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Goodwill and Intangible Assets Disclosure [Abstract]
Additional impairment charges on remaining long-lived assets	$ 0
Impairment of goodwill	$ 0	$ (76,501,000)

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Stock-Based Compensation - Stock-Based Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation	$ 6,000	$ 10,019
Cost of goods sold
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation	633	812
Research and development
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation	2,280	4,146
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Total stock-based compensation	$ 3,087	$ 5,061