10-Q

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-Q

(Mark One)

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

For the quarterly period ended June 30, 2021

OR

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

For the transition period from            to           

Commission file number: 001-35409

Merrimack Pharmaceuticals, Inc.

(Exact name of registrant as specified in its charter)

Delaware	04-3210530
(State or other jurisdiction of incorporation or organization)	(I.R.S. Employer Identification Number)

One Broadway, 14th Floor Cambridge, MA	02142
(Address of principal executive offices)	(Zip Code)

(617) 441-1000

(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, $0.01 par value	MACK	Nasdaq Global 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  ☒    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  ☒    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 in Rule 12b-2 of the Exchange Act).    Yes  ☐    No  ☒

As of August 2, 2021, there were 13,410,243 shares of Common Stock, $0.01 par value per share, outstanding.

TABLE OF CONTENTS

PART I

FINANCIAL INFORMATION

		Page
Item 1.	Financial Statements.	2
	Condensed Consolidated Balance Sheets – June 30, 2021 and December 31, 2020 (unaudited)	2
	Condensed Consolidated Statements of Operations and Comprehensive Loss – Three and Six Months Ended June 30, 2021 and 2020 (unaudited)	3
	Condensed Consolidated Statements of Stockholders’ Equity – June 30, 2021 and June 30, 2020 (unaudited)	4
	Condensed Consolidated Statements of Cash Flows – Six Months Ended June 30, 2021 and 2020 (unaudited)	5
	Notes to Condensed Consolidated Financial Statements (unaudited)	6
Item 2.	Management’s Discussion and Analysis of Financial Condition and Results of Operations.	10
Item 3.	Quantitative and Qualitative Disclosures About Market Risk.	14
Item 4.	Controls and Procedures.	15

PART II

OTHER INFORMATION

Item 1A.	Risk Factors.	16
Item 6.	Exhibits.	17
Signatures		18

i

FORWARD-LOOKING STATEMENTS

This Quarterly Report on Form 10-Q contains forward-looking statements that involve substantial risks and uncertainties. All statements, other than statements of historical facts, contained in this Quarterly Report on Form 10-Q, including statements regarding our strategy, future operations, future financial position, future revenues, projected costs, prospects, plans and objectives of management, are forward-looking statements. The words “anticipate,” “believe,” “estimate,” “expect,” “intend,” “may,” “plan,” “predict,” “project,” “target,” “potential,” “will,” “would,” “could,” “should,” “continue” and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words.

The forward-looking statements in this Quarterly Report on Form 10-Q include, among other things, statements about:

• our rights to receive payments related to the milestone events under the asset purchase and sale agreement with Ipsen S.A.;

• our rights to receive payments related to the milestone events under the asset purchase agreement with Elevation Oncology, Inc. (formerly known as 14ner Oncology, Inc.), when expected or at all;

• our intellectual property position;

• our cash runway and the sufficiency of our financial resources to fund our operations;

• our estimates regarding expenses, future revenues, capital requirements and needs for additional financing;

• our plans to seek to divert our remaining product candidates; and

• other risks detailed from time to time in our filings with the Securities and Exchange Commission (the “SEC”), press releases and other communications, including those set forth under “Risk Factors” included in our Annual Report on Form 10-K for the year ended December 31, 2020, and in the documents incorporated by reference herein and therein.

We may not actually achieve the plans, intentions or expectations disclosed in our forward-looking statements, and you should not place undue reliance on our forward-looking statements. Actual results or events could differ materially from the plans, intentions and expectations disclosed in the forward-looking statements we make. Our forward-looking statements do not reflect the potential impact of any future acquisitions, mergers, dispositions, joint ventures, collaborations or investments that we may make.

You should read this Quarterly Report on Form 10-Q and the documents that we have filed as exhibits to this Quarterly Report on Form 10-Q completely and with the understanding that our actual future results may be materially different from what we expect. We do not assume any obligation to update any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law.

NOTE REGARDING TRADEMARKS

ONIVYDE^® is a trademark of Ipsen S.A. Any other trademarks, trade names and service marks referred to in this Quarterly Report on Form 10-Q are the property of their respective owners.

1

PART I

FINANCIAL INFORMATION

Item 1.Financial Statements.

Merrimack Pharmaceuticals, Inc.
Condensed Consolidated Balance Sheets

(unaudited)

(in thousands, except per share amounts)	June 30, 2021			December 31, 2020
Assets
Current assets:
Cash and cash equivalents	$	14,909		$	14,038
Prepaid expenses and other current assets		805			2,506
Total current assets		15,714			16,544
Other assets		149			232
Total assets	$	15,863		$	16,776
Liabilities and stockholders’ equity
Current liabilities:
Accounts payable, accrued expenses and other	$	772		$	770
Total current liabilities		772			770
Total liabilities		772			770
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.01 par value: 10,000 shares authorized at June 30, 2021 and    December 31, 2020; no shares issued or outstanding at June 30, 2021 or    December 31, 2020		—			—
Common stock, $0.01 par value: 30,000 shares authorized at June 30, 2021 and    December 31, 2020; 13,410 and 13,380 shares issued and outstanding    at June 30, 2021 and December 31, 2020, respectively		1,334			1,334
Additional paid-in capital		558,849			558,309
Accumulated deficit		(545,092	)		(543,637	)
Total stockholders’ equity		15,091			16,006
Total liabilities and stockholders’ equity	$	15,863		$	16,776

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

2

Merrimack Pharmaceuticals, Inc.
Condensed Consolidated Statements of Operations and Comprehensive Loss

(unaudited)

	Three Months Ended June 30,						Six Months Ended June 30,
(in thousands, except per share amounts)	2021			2020			2021			2020
Operating expenses:
General and administrative expenses	$	778		$	1,184			1,524			3,119
Gain on sale of assets		—			—			(50	)		(2,139	)
Total operating expenses		778			1,184			1,474			980
Loss from operations		(778	)		(1,184	)		(1,474	)		(980	)
Other income:
Interest income		19			3			19			48
Other income, net		—			18			—			18
Total other income		19			21			19			66
Net loss and comprehensive loss	$	(759	)	$	(1,163	)	$	(1,455	)	$	(914	)
Net loss per common share - basic and diluted	$	(0.06	)	$	(0.09	)	$	(0.11	)	$	(0.07	)
Weighted-average common shares used to compute basic and    diluted net loss per common share		13,410			13,380			13,404			13,380

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

3

Merrimack Pharmaceuticals, Inc.

Condensed Consolidated Statements of Stockholders’ Equity

(unaudited)

	Common Stock
(in thousands)	Shares		Amount		Additional Paid-In Capital		Accumulated Deficit			Total Stockholders’ Equity
Balance at December 31, 2020		13,380	$	1,334	$	558,309	$	(543,637	)	$	16,006
Exercise of stock options		30		—		239		—			239
Stock-based compensation		—		—		208		—			208
Net loss		—		—		—		(696	)		(696	)
Balance at March 31, 2021		13,410	$	1,334	$	558,756	$	(544,333	)	$	15,757
Stock-based compensation		—		—		93		—			93
Net loss		—		—		—		(759	)		(759	)
Balance at June 30, 2021		13,410	$	1,334	$	558,849	$	(545,092	)	$	15,091

	Common Stock
(in thousands)	Shares		Amount		Additional Paid-In Capital		Accumulated Deficit			Total Stockholders’ Equity
Balance at December 31, 2019		13,380	$	1,334	$	556,587	$	(540,609	)	$	17,312
Stock-based compensation		—		—		484		—			484
Net income		—		—		—		249			249
Balance at March 31, 2020		13,380	$	1,334	$	557,071	$	(540,360	)	$	18,045
Stock-based compensation		—		—		464		—			464
Net loss		—		—		—		(1,163	)		(1,163	)
Balance at June 30, 2020		13,380	$	1,334	$	557,535	$	(541,523	)	$	17,346

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

4

Merrimack Pharmaceuticals, Inc.

Condensed Consolidated Statements of Cash Flows

(unaudited)

	Six Months Ended June 30,
(in thousands)	2021			2020
Cash flows from operating activities
Net loss	$	(1,455	)	$	(914	)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities
Gain on sale of in process research and development		(50	)		(2,139	)
Stock-based compensation expense		301			948
Changes in operating assets and liabilities:
Prepaid expenses and other assets		1,784			(444	)
Accounts payable, accrued expenses and other		2			(435	)
Net cash provided by (used in) operating activities		582			(2,984	)
Cash flows from investing activities
Proceeds from sale of in process research and development		50			2,139
Net cash provided by investing activities		50			2,139
Cash flows from financing activities
Proceeds from exercise of stock options		239			—
Net cash provided by financing activities		239			—
Net increase (decrease) in cash and cash equivalents		871			(845	)
Cash and cash equivalents, beginning of period		14,038			16,580
Cash and cash equivalents, end of period	$	14,909		$	15,735

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

5

Merrimack Pharmaceuticals, Inc.

Notes to Condensed Consolidated Financial Statements

(unaudited)

1. Nature of the Business

Merrimack Pharmaceuticals, Inc. (the “Company”) is a biopharmaceutical company based in Cambridge, Massachusetts that is entitled to receive up to $450.0 million in contingent milestone payments related to its sale of ONIVYDE^® and MM-436 (the “Commercial Business”) to Ipsen S.A. (“Ipsen”) in April 2017 (the “Ipsen Sale”). The Company does not have any ongoing research or development activities and is seeking potential acquirers for its remaining preclinical and clinical assets. The Company does not have any employees and instead uses external consultants for the operation of the Company.

The $450.0 million in contingent milestone payments resulting from the Ipsen Sale consist of:

• $225.0 million upon approval by the U.S. Food and Drug Administration (“FDA”) of ONIVYDE^® for the first-line treatment of metastatic adenocarcinoma of the pancreas, subject to certain conditions;

• $150.0 million upon approval by the FDA of ONIVYDE^® for the treatment of small-cell lung cancer after failure of first-line chemotherapy; and

• $75.0 million upon approval by the FDA of ONIVYDE^® for an additional indication unrelated to those described above.

On May 30, 2019, the Company announced the completion of its review of strategic alternatives, following which the Company’s board of directors (the “Board”) implemented a series of measures designed to extend the Company’s cash runway and preserve its ability to capture the potential milestone payments resulting from the Ipsen Sale. In connection with that announcement, the Company discontinued the discovery efforts on its remaining preclinical programs: MM-401, an agonistic antibody targeting a novel immuno-oncology target, TNFR2; and MM-201, a highly stabilized agonist-Fc fusion protein targeting death receptors 4 and 5. The Company is seeking potential acquirers for its remaining preclinical and clinical assets.

The Company’s termination of its executive management team and all other employees was substantially completed by June 28, 2019 and fully completed by July 12, 2019. As a result, the Company has not had any employees since July 2019. The Company has engaged external consultants to run the day-to-day operations of the Company. The Company has also entered into consulting agreements with certain former members of its executive management team who are supporting the Company’s relationship with current partners, assisting with the potential sale of remaining preclinical and clinical assets, and assisting with certain legal and regulatory matters and the continued wind-down of operations.

On July 12, 2019, the Company completed the sale to Elevation Oncology, Inc. (formerly known as 14ner Oncology, Inc.) (“Elevation”) of its anti-HER3 antibody programs, MM-121 (seribantumab) and MM-111 (the “Elevation sale”). In connection with the Elevation sale, the Company received an upfront cash payment of $3.5 million. The Company is also eligible to receive up to $54.5 million in additional potential development, regulatory approval and commercial-based milestone payments, consisting of:

• $3.0 million for achievement of the primary endpoint in the first registrational clinical study of either MM-121 or MM-111;

• Up to $16.5 million in total payments for the achievement of various regulatory approval and reimbursement-based milestones in the United States, Europe and Japan; and

• Up to $35.0 million in total payments for achieving various cumulative worldwide net sales targets between $100.0 million and $300.0 million for MM-121 and MM-111.

On March 27, 2020, the Company entered into an Asset Purchase Agreement (the “Asset Purchase Agreement”) with Celator Pharmaceuticals, Inc. (the “Buyer”), pursuant to which the Buyer agreed to purchase certain assets (the “Transferred Assets”) relating to certain of the Company’s preclinical nanoliposome programs (the “Transaction”). The Company and the Buyer completed the Transaction simultaneously with the execution of the Asset Purchase Agreement. Under the terms of the Asset Purchase Agreement, the Buyer paid to the Company a cash payment of $2.3 million and reimbursed the Company for $0.2 million related to certain specified expenses. The Company incurred $0.4 million expenses related to the Transaction.

6

The Company is subject to risks and uncertainties common to companies in the biopharmaceutical industry, including, among other things, development by competitors of new technological innovations, protection of proprietary technology and compliance with government regulations, approval by the FDA and other foreign health agencies to approve any pharmaceutical under development, obtaining insurance reimbursement for any drug if and when approved by regulators, and its ability to secure additional capital to fund operations. None of the Company’s product candidates are approved for any indication by the FDA or any other regulatory agency. The Company operates in an environment of rapid change in technology and substantial competition from pharmaceutical and biotechnology companies, among others. In addition, the Company is dependent upon the services of its external consultants for the operation of the Company. The Company’s business strategy depends substantially upon its ability to receive future milestone payments from Ipsen and Elevation. Any failure to achieve such milestones or a perception that the milestones may not be achieved will materially and adversely affect the Company and the value of its common stock.

In accordance with Accounting Standards Codification (“ASC”) 205-40, Going Concern, the Company has evaluated whether there are conditions and events, considered in the aggregate, that raise substantial doubt about the Company’s ability to continue as a going concern within one year after the date that the condensed consolidated financial statements are issued. As of June 30, 2021, the Company had an accumulated deficit of $545.1 million. During the six months ended June 30, 2021, the Company incurred net loss of $1.5 million and generated $0.6 million of cash in operating activities. The Company expects to continue to generate operating losses for the foreseeable future. The Company expects that its cash and cash equivalents of $14.9 million at June 30, 2021 will allow the Company to continue its operations into 2027, when the Company estimates the longest-term potential Ipsen milestone may be achieved. The continued viability of the Company beyond that point is dependent on its ability to realize milestone payments from its licensed product candidates, raise additional capital to finance its operations or to reduce operating expenses. There can be no assurance that the Company will be successful in receiving future milestone payments or able to obtain sufficient capital to cover its costs on acceptable terms, if at all.

The Company expects that it would seek to finance any future cash needs through a combination of divestitures of its product candidates or other assets, equity offerings and debt financings. There can be no assurance as to the timing, terms or consummation of any divestiture or financing, and the terms of any such financing may adversely affect the holdings or the rights of the Company’s stockholders or require the Company to relinquish rights to certain of its revenue streams or product candidates.

2. Summary of Significant Accounting Policies

Basis of Presentation

The accompanying condensed consolidated financial statements reflect the operations of Merrimack Pharmaceuticals, Inc. and its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated.

The condensed consolidated financial statements are unaudited and have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”).

The accounting policies followed in the preparation of the interim condensed consolidated financial statements are consistent in all material respects with those presented in Note 1 to the financial statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2020.

Unaudited Interim Financial Information

The condensed consolidated balance sheet as of December 31, 2020 was derived from audited financial statements, but does not include all disclosures required by GAAP. The condensed consolidated balance sheet as of June 30, 2021, the condensed consolidated statements of operations and comprehensive loss for the three and six months ended June 30, 2021 and 2020, the condensed consolidated statements of stockholders’ equity for the three and six months ended June 30, 2021 and 2020 and the condensed consolidated statements of cash flows for the six months ended June 30, 2021 and 2020 are unaudited. The unaudited interim condensed consolidated financial statements have been prepared on the same basis as the audited annual financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for the fair statement of the Company’s financial position as of June 30, 2021, the results of its operations for the three and six months ended June 30, 2021 and 2020, its statements of stockholders’ equity for the three and six months ended June 30, 2021 and 2020 and its statements of cash flows for the six months ended June 30, 2021 and 2020. The financial data and other information disclosed in the notes related to the three and six months ended June 30, 2021 and 2020 are unaudited. The results for the three and six months ended June 30, 2021 and 2020 are not necessarily indicative of results to be expected for the year ending December 31, 2021, any other interim periods, or any future year or period.

The unaudited interim financial statements of the Company included herein have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted from this report, as is permitted by such rules and regulations. These unaudited condensed consolidated financial statements should be read in conjunction with the audited financial statements and the notes thereto contained in the Company’s Annual Report on Form 10-K for the year ended December 31, 2020 filed with the SEC on March 10, 2021.

7

Use of Estimates

The preparation of financial statements in conformity with GAAP requires management to make estimates, assumptions and judgments that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and the reported amounts of expenses during the reporting periods. Significant estimates, assumptions and judgments reflected in these condensed consolidated financial statements include, but are not limited to, the accrual of research and development expenses and the valuation of stock-based awards. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Actual results could differ from the Company’s estimates.

3. Fair Value of Financial Instruments

The following tables show assets measured at fair value on a recurring basis as of June 30, 2021 and December 31, 2020:

	June 30, 2021
(in thousands)	Level 1		Level 2		Level 3
Cash equivalents:
Money market funds	$	13,493	$	—	$	—
Totals	$	13,493	$	—	$	—

	December 31, 2020
(in thousands)	Level 1		Level 2		Level 3
Cash equivalents:
Money market funds	$	13,943	$	—	$	—
Totals	$	13,943	$	—	$	—

There were no liabilities measured at fair value on a recurring basis as of June 30, 2021 and December 31, 2020.

4. Accounts Payable, Accrued Expenses and Other

Accounts payable, accrued expenses and other as of June 30, 2021 and December 31, 2020 consisted of the following:

(in thousands)	June 30, 2021		December 31, 2020
Accounts payable	$	173	$	123
Accrued goods and services		166		194
Accrued clinical trial costs		92		112
Others		341		341
Total accounts payable, accrued expenses and other	$	772	$	770

5. Stock-Based Compensation

On April 15, 2021, the Company’s Board of Directors adopted the 2021 Incentive Award Plan (the “2021 Plan”) to replace the 2011 Stock Incentive Plan (the “2011 Plan”). The 2021 Plan was approved by the Company’s stockholders at the Company’s Annual Meeting of Stockholders held on June 10, 2021.  The 2021 Plan is administered by the Company’s Board of Directors and permits the Company to grant incentive and non-qualified stock options, stock appreciation rights, restricted stock, restricted stock units and other stock-based awards.

There were 22,000 options granted during the three and six months ended June 30, 2021 under 2021 Plan. The weighted-average grant date fair value per share of stock options granted during the three and six months ended June 30, 2021 was $3.68. There were no options granted during the three and six months ended June 30, 2020. At June 30, 2021, there were 253,000 shares remaining available for grant under the 2021 Plan.

8

The fair value of stock options granted to employees during the three and six months ended June 30, 2021 was estimated at the date of grant using the following assumptions:

	Three and Six Months Ended June 30,
	2021
Risk-free interest rate		0.73	%
Expected dividend yield	0%
Expected term	5.22 years
Expected volatility	68.48%

The Company recognized stock-based compensation expense of $0.1 million, $0.3 million, $0.5 million and $0.9 million in general and administrative expense during the three and six months ended June 30, 2021 and 2020, respectively.

6. Net Loss Per Common Share

Basic net loss per share is calculated by dividing the net loss attributable to Merrimack Pharmaceuticals, Inc. by the weighted-average number of common shares outstanding during the period.

Diluted net loss per share is computed by dividing the net loss attributable to Merrimack Pharmaceuticals, Inc. by the weighted-average number of dilutive common shares outstanding during the period. Dilutive shares outstanding is calculated by adding to the weighted shares outstanding any potential (unissued) shares of common stock from outstanding stock options based on the treasury stock method. Outstanding stock options were not included in the diluted net loss per share calculation because the options were out of the money or to do so would have been antidilutive (i.e., the total proceeds upon exercise would have exceeded the market value of the underlying common shares). In a period when a net loss is reported, all common stock equivalents are excluded from the calculation because they would have an anti-dilutive effect, meaning the loss per share would be reduced. Therefore, in periods where a loss is reported, there is no difference in basic and dilutive loss per share.

Stock options are excluded from the calculation of diluted loss per share because the net loss for the three and six months ended June 30, 2021 and 2020 causes such securities to be anti-dilutive. Outstanding options excluded from the calculation of diluted loss per share for the three and six months ended June 30, 2021 and 2020 are shown in the chart below:

	Three Months Ended June 30,				Six Months Ended June 30,
(in thousands)	2021		2020		2021		2020
Outstanding options to purchase common stock		1,778		1,877		1,778		1,877

7. Restructuring Activities

On November 7, 2018, the Company announced that it was implementing a reduction in headcount as part of a corporate restructuring. All the restructuring expenses were paid off as of December 31, 2020.

No additional restructuring expenses was recognized during the three and six months ended June 30, 2020. The Company paid approximately less than $0.1 million and $0.1 million of these restructuring expenses during the three and six months ended June 30, 2020, respectively. No additional restructuring expenses were recognized or paid during the three and six months ended June 30, 2021.

The following table summarizes the charges related to the restructuring activities as of June 30, 2020:

(in thousands)	Accrued Restructuring Expenses at December 31, 2019		Expenses		Less: Payments			Accrued Restructuring Expenses at June 30, 2020
Severance, benefits and related costs due to workforce    reduction	$	66	$	—	$	(51	)	$	15
Totals	$	66	$	—	$	(51	)	$	15

8. Recent Accounting Pronouncements

From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (“FASB”) or other standard setting bodies that the Company adopts as of the specified effective date. Unless otherwise discussed above, the Company does not believe that the adoption of recently issued standards has or may have a material impact on the Company’s condensed consolidated financial statements or disclosures.

9

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

The following discussion of our financial condition and results of operations should be read in conjunction with our financial statements and the notes to those financial statements appearing elsewhere in this Quarterly Report on Form 10-Q and the audited consolidated financial statements and notes thereto and management’s discussion and analysis of financial condition and results of operations for the year ended December 31, 2020 included in our Annual Report on Form 10-K. This discussion contains forward-looking statements that involve significant risks and uncertainties. As a result of many factors, such as those set forth in Part II, Item 1A. Risk Factors of this Quarterly Report on Form 10-Q, which are incorporated herein by reference, our actual results may differ materially from those anticipated in these forward-looking statements.

Overview

We are a biopharmaceutical company based in Cambridge, Massachusetts that is entitled to receive up to $450.0 million in contingent milestone payments related to our sale of ONIVYDE^® to Ipsen S.A., or Ipsen, in April 2017 and up to $54.5 million in contingent milestone payments related to our sale of MM-121 and MM-111 to Elevation Oncology, Inc. (formerly known as 14ner Oncology, Inc.), or Elevation, in July 2019. We do not have any ongoing research or development activities and are seeking potential acquirers for our remaining preclinical and clinical assets. We do not have any employees and instead use external consultants for the operation of our company.

On April 3, 2017, we completed the sale of ONIVYDE^® and MM-436 (the “commercial business”) to Ipsen (the “Ipsen sale”). In connection with the Ipsen sale, we are eligible to receive up to $450.0 million in additional regulatory approval-based milestone payments.

The remaining up to $450.0 million in potential milestone payments resulting from the Ipsen sale consist of:

• $225.0 million upon approval by the U.S. Food and Drug Administration, or FDA, of ONIVYDE^® for the first-line treatment of metastatic adenocarcinoma of the pancreas, subject to certain conditions;

• $150.0 million upon approval by the FDA of ONIVYDE^® for the treatment of small-cell lung cancer after failure of first-line chemotherapy; and

• $75.0 million upon approval by the FDA of ONIVYDE^® for an additional indication unrelated to those described above.

Our non-commercial assets, including our clinical and preclinical development programs, were not included in the Ipsen sale and remain assets of ours.

On May 30, 2019, we announced the completion of our review of strategic alternatives, following which our board of directors implemented a series of measures which we believe allow us to extend our cash runway into 2027 and preserve our ability to capture the potential milestone payments resulting from the Ipsen sale. We have based this estimate on assumptions that may prove to be wrong, and we could use our financial resources sooner than we currently expect. In connection with that announcement, we discontinued the discovery efforts on our remaining preclinical programs: MM-401, an agonistic antibody targeting a novel immuno-oncology target, TNFR2; and MM-201, a highly stabilized agonist-Fc fusion protein targeting death receptors 4 and 5. We are seeking potential acquirers for our remaining preclinical and clinical assets.

The termination of our executive management team and all other employees was substantially completed by June 28, 2019 and fully completed by July 12, 2019. As of July 12, 2019, we do not have any employees. We have engaged external consultants to run our day-to-day operations. We have also entered into consulting agreements with certain former members of our executive management team who are supporting our relationship with current partners, assisting with the potential sale of remaining preclinical and clinical assets, and assisting with certain legal and regulatory matters and the continued wind-down of operations.

On July 12, 2019, we completed the sale to Elevation, or the Elevation sale, of our anti-HER3 antibody programs, MM-121 (seribantumab) and MM-111. In connection with the Elevation sale, we received an upfront cash payment of $3.5 million and are eligible to receive up to $54.5 million in additional potential development, regulatory approval and commercial-based milestone payments, consisting of:

• $3.0 million for achievement of the primary endpoint in the first registrational clinical study of either MM-121 or MM-111;

• Up to $16.5 million in total payments for the achievement of various regulatory approval and reimbursement-based milestones in the United States, Europe and Japan; and

• Up to $35.0 million in total payments for achieving various cumulative worldwide net sales targets between $100.0 million and $300.0 million for MM-121 and MM-111.

10

On March 27, 2020, we entered into an Asset Purchase Agreement (the “Asset Purchase Agreement”) with Celator Pharmaceuticals, Inc. (the “Buyer”), pursuant to which the Buyer agreed to purchase certain assets (the “Transferred Assets”) relating to certain of our preclinical nanoliposome programs (the “Transaction”). We completed the Transaction simultaneously with the execution of the Asset Purchase Agreement. Under the terms of the Asset Purchase Agreement, the Buyer paid to us a cash payment of $2.3 million and reimbursed us for $0.2 million related to certain specified expenses and to assume certain liabilities with respect to the Transferred Assets. We incurred $0.4 million expenses related to the Transaction.

We previously devoted substantially all of our resources to our drug discovery and development efforts, including conducting clinical trials for our product candidates, protecting our intellectual property and providing general and administrative support for these operations. We have financed our operations primarily through private placements of convertible preferred stock, collaborations, public offerings of our securities, secured debt financings, sales of ONIVYDE^® and the Ipsen sale.

As of June 30, 2021, we had unrestricted cash and cash equivalents of $14.9 million. We expect that our cash and cash equivalents as of June 30, 2021 will be sufficient to continue our operations into 2027, when we estimate the longest-term potential Ipsen milestone may be achieved.

As of June 30, 2021, we had an accumulated deficit of $545.1 million. Our net loss from our continuing operations was $1.5 million and $0.9 million for the six months ended June 30, 2021 and 2020, respectively. We do not expect to have any research and development expenses going forward. We do not expect to be profitable from our continuing operations in the future.

Financial Operations Overview

General and administrative expenses

General and administrative expenses consist primarily of stock-based compensation expenses, legal, intellectual property, business development, finance, information technology, corporate communications and investor relations. Other general and administrative expenses include costs for board of director’s costs, insurance expenses, legal and professional fees, and accounting and information technology services fees.

Interest income

Interest income consists primarily of interest income associated with our money market fund.

Critical Accounting Policies and Significant Judgments and Estimates

Our management’s discussion and analysis of our financial condition and results of operations is based on our condensed consolidated financial statements, which we have prepared in accordance with the rules and regulations of the Securities and Exchange Commission, or the SEC, and generally accepted accounting principles in the United States, or GAAP. The preparation of these condensed consolidated financial statements requires us to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities at the date of the financial statements, as well as the reported expenses during the reporting periods. We evaluate our estimates and judgments on an ongoing basis. We base our estimates on historical experience and on various other factors that we believe are reasonable under the circumstances, the results of which form the basis for making judgments about the carrying value of assets and liabilities that are not readily apparent from other sources. Our actual results may differ from these estimates under different assumptions or conditions.

Our critical accounting policies and the methodologies and assumptions we apply under them have not materially changed since March 10, 2021, the date we filed our Annual Report on Form 10-K for the year ended December 31, 2020. For more information on our critical accounting policies, refer to our Annual Report on Form 10-K for the year ended December 31, 2020.

11

Results of Operations

Comparison of the three months ended June 30, 2021 and 2020

	Three Months Ended June 30,
(in thousands)	2021			2020
Operating expenses:
General and administrative expenses	$	778		$	1,184
Total operating expenses		778			1,184
Loss from operations		(778	)		(1,184	)
Interest income		19			3
Other income, net		—			18
Net loss	$	(759	)	$	(1,163	)

General and administrative expenses

General and administrative expenses were $0.8 million for the three months ended June 30, 2021 compared to $1.2 million for the three months ended June 30, 2020, a decrease of $0.4 million, or 34%. This decrease was primarily attributable to the decrease in both share-based compensation expense and consulting fees.

Interest income

Interest income was less than $0.1 million for the three months ended June 30, 2021 and 2020, primarily attributable to the interest income received related to federal tax refund.

Comparison of the six months ended June 30, 2021 and 2020

	Six Months Ended June 30,
(in thousands)	2021			2020
Operating expenses:
General and administrative expenses		1,524			3,119
Gain on sale of assets		(50	)		(2,139	)
Total operating expenses		1,474			980
Loss from operations		(1,474	)		(980	)
Interest income		19			48
Other income, net		—			18
Net loss	$	(1,455	)	$	(914	)

General and administrative expenses

General and administrative expenses were $1.5 million for the six months ended June 30, 2021 compared to $3.1 million for the six months ended June 30, 2020, a decrease of $1.6 million, or 51%. This decrease was primarily attributable to the decrease in both share-based compensation expense and consulting fees.

Gain on sales of assets

Gain on sales of assets was less than $0.1 million for the six months ended June 30, 2021, attributable to the sale of certain of our preclinical programs to a third party. Gain on sales of assets was $2.1 million for the six months ended June 30, 2020, attributable to the sale of certain of our preclinical nanoliposome programs to the Buyer.

Interest income

Interest income was less than $0.1 million for the six months ended June 30, 2021 and 2020, primarily attributable to the decrease of our interest bearing cash and cash equivalents accounts.

12

Liquidity and Capital Resources

Sources of liquidity

We have financed our operations through June 30, 2021 primarily through private placements of convertible preferred stock, collaborations, public offerings of our securities, secured debt financings, sales of our common stock and sales of our commercial and in-process research and development assets. As of June 30, 2021, we had unrestricted cash and cash equivalents of $14.9 million.

Cash flows

The following table provides information regarding our cash flows for the six months ended June 30, 2021 and 2020:

	Six Months Ended June 30,
(in thousands)	2021		2020
Net cash provided by (used in) operating activities	$	582	$	(2,984	)
Net cash provided by investing activities		50		2,139
Net cash provided by financing activities		239		—
Net increase (decrease) in cash and cash equivalents	$	871	$	(845	)

Operating activities

Cash provided by operating activities of $0.6 million during the six months ended June 30, 2021 was primarily a result of our $1.5 million net loss from operations. The net loss was offset by $0.3 million in non-cash stock-based compensation and $1.8 million resulting from a change in operating assets and liabilities due to a decrease of $1.8 million in prepaid expense and other assets related to our federal tax refund of $2.0 million offset by an increase in prepaid insurance of $0.2 million.

Cash used in operating activities of $3.0 million during the six months ended June 30, 2020 was primarily a result of our $0.9 million net loss from operations and an increase in assets and liabilities of $0.9 million. The increase in operating assets and liabilities during the six months ended June 30, 2020 was primarily driven by decreases to accounts payable, accrued expenses and other expenses due to timing of payments and increase in prepaid expenses and other assets. This increase was offset by non-cash items, including a $2.1 million gain on the sale of in-process research and development, offset by $0.9 million of stock-based compensation expense.  

Investing activities

Cash provided by investing activities of $0.1 million and $2.1 million during the six months ended June 30, 2021 and 2020, respectively, was due to proceeds from the sale of in-process research and development assets.

Financing activities

Cash provided by financing activities of $0.2 million during the six months ended June 30, 2021 was due to proceeds from the exercise of stock options. There was no cash provided by or used in financing activities during the six months ended June 30, 2020.

Funding requirements

We have incurred significant expenses and operating losses to date. On May 30, 2019, we announced the completion of our review of strategic alternatives, following which our board of directors implemented a series of measures designed to extend our cash runway into 2027 and preserve our ability to capture the potential milestone payments resulting from the Ipsen sale. In connection with that announcement, we discontinued the discovery efforts on our remaining preclinical programs and implemented a reduction in headcount resulting in the termination of all remaining employees as of July 12, 2019. Our future capital requirements will depend on many factors, including:

• the timing and amount of potential milestone payments related to ONIVYDE^® that we may receive from Ipsen;

• the timing and amount of potential milestone payments that we may receive from Elevation;

• the timing and amount of any special dividend to our stockholders that our board of directors may declare;

• the timing and amount of general and administrative expenses required to continue to operate our company;

13

• the extent to which we owe any taxes for current, future or prior periods, including as a result of any audits by taxing authorities;

• the extent to which we invest in any future research or development activities of our product candidates;

• the costs of preparing, filing and prosecuting patent applications and maintaining, enforcing and defending intellectual property-related claims;

• the extent to which we acquire or invest in businesses, products and technologies; and

• the costs associated with operating as a public company and maintaining compliance with exchange listing and SEC requirements.

We do not believe that we will be able to raise a material amount of capital through the sale of our equity securities or debt financing.  Rather, our goal is to judiciously expend our remaining cash until such time, if ever, as we receive additional milestone payments from Ipsen and Elevation.   There can be no assurance as to the timing, terms or consummation of any financing or divestitures of our few remaining intellectual property assets. We do not have any committed external sources of funds. To the extent that we raise additional capital through the sale of equity or convertible debt securities, the ownership interest of our stockholders will be diluted, and the terms of these securities may include liquidation or other preferences that adversely affect the rights of our stockholders. Debt financing, if available, may involve agreements that include covenants limiting or restricting our ability to take specific actions, such as incurring additional debt, making capital expenditures or declaring dividends. If we raise additional funds through arrangements with third parties, we may have to relinquish valuable rights to our future revenue streams or product candidates.

Contractual Obligations and Commitments

There were no material changes to our contractual obligations and commitments described under Management’s Discussion and Analysis of Financial Condition and Results of Operations in our Annual Report on Form 10-K for the year ended December 31, 2020, as filed with the SEC on March 10, 2021.

Off-Balance Sheet Arrangements

We did not have during the periods presented, and we do not currently have, any off-balance sheet arrangements, as defined under SEC rules.

Recent Accounting Pronouncements

See Note 8, “Recent Accounting Pronouncements,” in the accompanying notes to the condensed consolidated financial statements for a full description of recent accounting pronouncements.

Item 3.Quantitative and Qualitative Disclosures About Market Risk.

We invest in money market funds. The goals of our investment policy are preservation of capital, fulfillment of liquidity needs and fiduciary control of cash and investments. We also seek to maximize income from our investments without assuming significant risk.

Our primary exposure to market risk is interest income sensitivity, which is affected by changes in the general level of interest rates, particularly because our investments are money market funds. Due to the short-term duration of our investment portfolio and the low risk profile of our investments, an immediate 10% change in interest rates would not have a material effect on the fair market value of our portfolio. We have the ability and intention to hold our investments until maturity, and therefore, we would not expect our operating results or cash flows to be affected to any significant degree by the effect of a sudden change in market interest rates on our investment portfolio.

We do not currently have any auction rate or mortgage-backed securities. We do not believe our cash and cash equivalents have significant risk of default or liquidity, however we cannot provide absolute assurance that in the future our investments will not be subject to adverse changes in market value.

14

Item 4.Controls and Procedures.

Evaluation of Disclosure Controls and Procedures

Our management, with the participation of our principal executive and financial officer, evaluated the effectiveness of our disclosure controls and procedures as of June 30, 2021. The term “disclosure controls and procedures,” as defined in Rules 13a-15(e) and 15d-15(e) under the Exchange Act means controls and other procedures of a company that are designed to ensure that information required to be disclosed by a company in the reports that it files or submits under the Exchange Act is recorded, processed, summarized and reported, within the time periods specified in the SEC’s rules and forms. Disclosure controls and procedures include, without limitation, controls and procedures designed to ensure that information required to be disclosed by a company in the reports that it files or submits under the Exchange Act is accumulated and communicated to the company’s management, including its principal executive and principal financial officers, as appropriate to allow timely decisions regarding required disclosure. Management recognizes that any controls and procedures, no matter how well designed and operated, can provide only reasonable assurance of achieving their objectives and management necessarily applies its judgment in evaluating the cost-benefit relationship of possible controls and procedures. Based on the evaluation of our disclosure controls and procedures as of June 30, 2021, our principal executive and financial officer concluded that, as of such date, our disclosure controls and procedures were effective at the reasonable assurance level.

Changes in Internal Control Over Financial Reporting

No change in our internal control over financial reporting (as defined in Rules 13a-15(f) and 15d-15(f) under the Exchange Act) occurred during the six months ended June 30, 2021 that has materially affected, or is reasonably likely to materially affect, our internal control over financial reporting.

15

PART II

OTHER INFORMATION

Item 1A.Risk Factors.

In addition to the other information set forth in this Quarterly Report on Form 10-Q, you should carefully consider the factors discussed under the caption “Risk Factors” that appear in Item 1A of our Annual Report on Form 10-K for the year ended December 31, 2020, which was filed with the SEC on March 10, 2021 (the “2020 Annual Report on Form 10-K”). There have been no material changes from the risk factors previously disclosed in the 2020 Annual Report on Form 10-K.

16

Item 6. Exhibits.

Exhibit Number	Description of Exhibit
31.1*	Certification of Principal Executive Officer pursuant to Rule 13a-14(a) or Rule 15d-14(a) of the Securities Exchange Act of 1934, as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002
31.2*	Certification of Principal Financial Officer pursuant to Rule 13a-14(a) or Rule 15d-14(a) of the Securities Exchange Act of 1934, as adopted pursuant to Section 302 of the Sarbanes-Oxley Act of 2002
32.1+	Certification of Principal Executive Officer pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002
32.2+	Certification of Principal Financial Officer pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002
101.INS*	Inline XBRL Instance Document
101.SCH*	Inline XBRL Taxonomy Extension Schema Document
101.CAL*	Inline XBRL Taxonomy Extension Calculation Linkbase Document
101.DEF*	Inline XBRL Taxonomy Extension Definition Linkbase Document
101.LAB*	Inline XBRL Taxonomy Extension Label Linkbase Database
101.PRE*	Inline XBRL Taxonomy Extension Presentation Linkbase Document
104*	Cover Page Interactive Data File (embedded within the Inline XBRL document)

* Filed herewith.

+ Furnished herewith.

17

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.

	MERRIMACK PHARMACEUTICALS, INC.
Date: August 5, 2021	By:	/s/ Gary L. Crocker
		Gary L. Crocker
		President
		(Principal Financial Officer)

18

EX-31.1

Exhibit 31.1

CERTIFICATIONS

I, Gary L. Crocker, certify that:

1. I have reviewed this Quarterly Report on Form 10-Q of Merrimack Pharmaceuticals, Inc.;

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 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; and

5. The registrant’s other certifying officer 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: August 5, 2021	/s/ Gary L. Crocker
	Gary L. Crocker
	President
	(Principal Executive Officer)

EX-31.2

Exhibit 31.2

CERTIFICATIONS

I, Gary L. Crocker, certify that:

1. I have reviewed this Quarterly Report on Form 10-Q of Merrimack Pharmaceuticals, Inc.;

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 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; and

5. The registrant’s other certifying officer 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: August 5, 2021	/s/ Gary L. Crocker
	Gary L. Crocker
	President
	(Principal Financial Officer)

EX-32.1

Exhibit 32.1

CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350,

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report on Form 10-Q of Merrimack Pharmaceuticals, Inc. (the “Company”) for the period ended June 30, 2021 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), the undersigned, Gary L. Crocker, President of the Company, hereby certifies, pursuant to 18 U.S.C. Section 1350, that to his knowledge:

(1) the Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

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

Date: August 5, 2021	/s/ Gary L. Crocker
	Gary L. Crocker
	President
	(Principal Executive Officer)

EX-32.2

Exhibit 32.2

CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350,

AS ADOPTED PURSUANT TO

SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002

In connection with the Quarterly Report on Form 10-Q of Merrimack Pharmaceuticals, Inc. (the “Company”) for the period ended June 30, 2021 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), the undersigned, Gary L. Crocker, President of the Company, hereby certifies, pursuant to 18 U.S.C. Section 1350, that to his knowledge:

(1) the Report fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

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

Date: August 5, 2021	/s/ Gary L. Crocker
	Gary L. Crocker
	President
	(Principal Financial Officer)

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Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2021	Aug. 02, 2021
Cover [Abstract]
Document Type	10-Q
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Document Fiscal Year Focus	2021
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Entity Incorporation, State or Country Code	DE
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Entity Address, Address Line One	One Broadway
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Entity Address, State or Province	MA
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Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 14,909	$ 14,038
Prepaid expenses and other current assets	805	2,506
Total current assets	15,714	16,544
Other assets	149	232
Total assets	15,863	16,776
Current liabilities:
Accounts payable, accrued expenses and other	772	770
Total current liabilities	772	770
Total liabilities	772	770
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.01 par value: 10,000 shares authorized at June 30, 2021 and December 31, 2020; no shares issued or outstanding at June 30, 2021 or December 31, 2020
Common stock, $0.01 par value: 30,000 shares authorized at June 30, 2021 and December 31, 2020; 13,410 and 13,380 shares issued and outstanding at June 30, 2021 and December 31, 2020, respectively	1,334	1,334
Additional paid-in capital	558,849	558,309
Accumulated deficit	(545,092)	(543,637)
Total stockholders’ equity	15,091	16,006
Total liabilities and stockholders’ equity	$ 15,863	$ 16,776

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Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2021	Dec. 31, 2020
Statement Of Financial Position [Abstract]
Preferred stock, par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Preferred stock, shares outstanding	0	0
Common stock, par value	$ 0.01	$ 0.01
Common stock, shares authorized	30,000,000	30,000,000
Common stock, shares issued	13,410,000	13,380,000
Common stock, shares outstanding	13,410,000	13,380,000

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Condensed Consolidated Statements of Operations and Comprehensive (Loss) Income - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Operating expenses:
General and administrative expenses	$ 778	$ 1,184	$ 1,524	$ 3,119
Gain on sale of assets			(50)	(2,139)
Total operating expenses	778	1,184	1,474	980
Loss from operations	(778)	(1,184)	(1,474)	(980)
Other income:
Interest income	19	3	19	48
Other income, net		18		18
Total other income	19	21	19	66
Net loss and comprehensive loss	$ (759)	$ (1,163)	$ (1,455)	$ (914)
Net loss per common share - basic and diluted	$ (0.06)	$ (0.09)	$ (0.11)	$ (0.07)
Weighted-average common shares used to compute basic and diluted net loss per common share	13,410	13,380	13,404	13,380

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Condensed Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Deficit [Member]
Balance at Dec. 31, 2019	$ 17,312	$ 1,334	$ 556,587	$ (540,609)
Balance (in shares) at Dec. 31, 2019		13,380
Stock-based compensation	484		484
Net income (loss)	249			249
Balance at Mar. 31, 2020	18,045	$ 1,334	557,071	(540,360)
Balance (in shares) at Mar. 31, 2020		13,380
Balance at Dec. 31, 2019	17,312	$ 1,334	556,587	(540,609)
Balance (in shares) at Dec. 31, 2019		13,380
Net income (loss)	(914)
Balance at Jun. 30, 2020	17,346	$ 1,334	557,535	(541,523)
Balance (in shares) at Jun. 30, 2020		13,380
Balance at Mar. 31, 2020	18,045	$ 1,334	557,071	(540,360)
Balance (in shares) at Mar. 31, 2020		13,380
Stock-based compensation	464		464
Net income (loss)	(1,163)			(1,163)
Balance at Jun. 30, 2020	17,346	$ 1,334	557,535	(541,523)
Balance (in shares) at Jun. 30, 2020		13,380
Balance at Dec. 31, 2020	16,006	$ 1,334	558,309	(543,637)
Balance (in shares) at Dec. 31, 2020		13,380
Exercise of stock options	239		239
Exercise of stock options (in shares)		30
Stock-based compensation	208		208
Net income (loss)	(696)			(696)
Balance at Mar. 31, 2021	15,757	$ 1,334	558,756	(544,333)
Balance (in shares) at Mar. 31, 2021		13,410
Balance at Dec. 31, 2020	16,006	$ 1,334	558,309	(543,637)
Balance (in shares) at Dec. 31, 2020		13,380
Net income (loss)	(1,455)
Balance at Jun. 30, 2021	15,091	$ 1,334	558,849	(545,092)
Balance (in shares) at Jun. 30, 2021		13,410
Balance at Mar. 31, 2021	15,757	$ 1,334	558,756	(544,333)
Balance (in shares) at Mar. 31, 2021		13,410
Stock-based compensation	93		93
Net income (loss)	(759)			(759)
Balance at Jun. 30, 2021	$ 15,091	$ 1,334	$ 558,849	$ (545,092)
Balance (in shares) at Jun. 30, 2021		13,410

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Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2021	Jun. 30, 2020
Cash flows from operating activities
Net income (loss)	$ (759)	$ (696)	$ (1,163)	$ 249	$ (1,455)	$ (914)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities
Gain on sale of in process research and development					(50)	(2,139)
Stock-based compensation expense					301	948
Changes in operating assets and liabilities:
Prepaid expenses and other assets					1,784	(444)
Accounts payable, accrued expenses and other					2	(435)
Net cash provided by (used in) operating activities					582	(2,984)
Cash flows from investing activities
Proceeds from sale of in process research and development					50	2,139
Net cash provided by investing activities					50	2,139
Cash flows from financing activities
Proceeds from exercise of stock options					239
Net cash provided by financing activities					239
Net increase (decrease) in cash and cash equivalents					871	(845)
Cash and cash equivalents, beginning of period		$ 14,038		$ 16,580	14,038	16,580
Cash and cash equivalents, end of period	$ 14,909		$ 15,735		$ 14,909	$ 15,735

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Nature of the Business

6 Months Ended

Jun. 30, 2021

Organization Consolidation And Presentation Of Financial Statements [Abstract]

Nature of the Business

1. Nature of the Business

Merrimack Pharmaceuticals, Inc. (the “Company”) is a biopharmaceutical company based in Cambridge, Massachusetts that is entitled to receive up to $450.0 million in contingent milestone payments related to its sale of ONIVYDE^® and MM-436 (the “Commercial Business”) to Ipsen S.A. (“Ipsen”) in April 2017 (the “Ipsen Sale”). The Company does not have any ongoing research or development activities and is seeking potential acquirers for its remaining preclinical and clinical assets. The Company does not have any employees and instead uses external consultants for the operation of the Company.

The $450.0 million in contingent milestone payments resulting from the Ipsen Sale consist of:

• $225.0 million upon approval by the U.S. Food and Drug Administration (“FDA”) of ONIVYDE^® for the first-line treatment of metastatic adenocarcinoma of the pancreas, subject to certain conditions;

• $150.0 million upon approval by the FDA of ONIVYDE^® for the treatment of small-cell lung cancer after failure of first-line chemotherapy; and

• $75.0 million upon approval by the FDA of ONIVYDE^® for an additional indication unrelated to those described above.

On May 30, 2019, the Company announced the completion of its review of strategic alternatives, following which the Company’s board of directors (the “Board”) implemented a series of measures designed to extend the Company’s cash runway and preserve its ability to capture the potential milestone payments resulting from the Ipsen Sale. In connection with that announcement, the Company discontinued the discovery efforts on its remaining preclinical programs: MM-401, an agonistic antibody targeting a novel immuno-oncology target, TNFR2; and MM-201, a highly stabilized agonist-Fc fusion protein targeting death receptors 4 and 5. The Company is seeking potential acquirers for its remaining preclinical and clinical assets.

The Company’s termination of its executive management team and all other employees was substantially completed by June 28, 2019 and fully completed by July 12, 2019. As a result, the Company has not had any employees since July 2019. The Company has engaged external consultants to run the day-to-day operations of the Company. The Company has also entered into consulting agreements with certain former members of its executive management team who are supporting the Company’s relationship with current partners, assisting with the potential sale of remaining preclinical and clinical assets, and assisting with certain legal and regulatory matters and the continued wind-down of operations.

On July 12, 2019, the Company completed the sale to Elevation Oncology, Inc. (formerly known as 14ner Oncology, Inc.) (“Elevation”) of its anti-HER3 antibody programs, MM-121 (seribantumab) and MM-111 (the “Elevation sale”). In connection with the Elevation sale, the Company received an upfront cash payment of $3.5 million. The Company is also eligible to receive up to $54.5 million in additional potential development, regulatory approval and commercial-based milestone payments, consisting of:

• $3.0 million for achievement of the primary endpoint in the first registrational clinical study of either MM-121 or MM-111;

• Up to $16.5 million in total payments for the achievement of various regulatory approval and reimbursement-based milestones in the United States, Europe and Japan; and

• Up to $35.0 million in total payments for achieving various cumulative worldwide net sales targets between $100.0 million and $300.0 million for MM-121 and MM-111.

On March 27, 2020, the Company entered into an Asset Purchase Agreement (the “Asset Purchase Agreement”) with Celator Pharmaceuticals, Inc. (the “Buyer”), pursuant to which the Buyer agreed to purchase certain assets (the “Transferred Assets”) relating to certain of the Company’s preclinical nanoliposome programs (the “Transaction”). The Company and the Buyer completed the Transaction simultaneously with the execution of the Asset Purchase Agreement. Under the terms of the Asset Purchase Agreement, the Buyer paid to the Company a cash payment of $2.3 million and reimbursed the Company for $0.2 million related to certain specified expenses. The Company incurred $0.4 million expenses related to the Transaction.

The Company is subject to risks and uncertainties common to companies in the biopharmaceutical industry, including, among other things, development by competitors of new technological innovations, protection of proprietary technology and compliance with government regulations, approval by the FDA and other foreign health agencies to approve any pharmaceutical under development, obtaining insurance reimbursement for any drug if and when approved by regulators, and its ability to secure additional capital to fund operations. None of the Company’s product candidates are approved for any indication by the FDA or any other regulatory agency. The Company operates in an environment of rapid change in technology and substantial competition from pharmaceutical and biotechnology companies, among others. In addition, the Company is dependent upon the services of its external consultants for the operation of the Company. The Company’s business strategy depends substantially upon its ability to receive future milestone payments from Ipsen and Elevation. Any failure to achieve such milestones or a perception that the milestones may not be achieved will materially and adversely affect the Company and the value of its common stock.

In accordance with Accounting Standards Codification (“ASC”) 205-40, Going Concern, the Company has evaluated whether there are conditions and events, considered in the aggregate, that raise substantial doubt about the Company’s ability to continue as a going concern within one year after the date that the condensed consolidated financial statements are issued. As of June 30, 2021, the Company had an accumulated deficit of $545.1 million. During the six months ended June 30, 2021, the Company incurred net loss of $1.5 million and generated $0.6 million of cash in operating activities. The Company expects to continue to generate operating losses for the foreseeable future. The Company expects that its cash and cash equivalents of $14.9 million at June 30, 2021 will allow the Company to continue its operations into 2027, when the Company estimates the longest-term potential Ipsen milestone may be achieved. The continued viability of the Company beyond that point is dependent on its ability to realize milestone payments from its licensed product candidates, raise additional capital to finance its operations or to reduce operating expenses. There can be no assurance that the Company will be successful in receiving future milestone payments or able to obtain sufficient capital to cover its costs on acceptable terms, if at all.

The Company expects that it would seek to finance any future cash needs through a combination of divestitures of its product candidates or other assets, equity offerings and debt financings. There can be no assurance as to the timing, terms or consummation of any divestiture or financing, and the terms of any such financing may adversely affect the holdings or the rights of the Company’s stockholders or require the Company to relinquish rights to certain of its revenue streams or product candidates.

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Summary of Significant Accounting Policies

6 Months Ended

Jun. 30, 2021

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

2. Summary of Significant Accounting Policies

Basis of Presentation

The accompanying condensed consolidated financial statements reflect the operations of Merrimack Pharmaceuticals, Inc. and its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated.

The condensed consolidated financial statements are unaudited and have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”).

The accounting policies followed in the preparation of the interim condensed consolidated financial statements are consistent in all material respects with those presented in Note 1 to the financial statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2020.

Unaudited Interim Financial Information

The condensed consolidated balance sheet as of December 31, 2020 was derived from audited financial statements, but does not include all disclosures required by GAAP. The condensed consolidated balance sheet as of June 30, 2021, the condensed consolidated statements of operations and comprehensive loss for the three and six months ended June 30, 2021 and 2020, the condensed consolidated statements of stockholders’ equity for the three and six months ended June 30, 2021 and 2020 and the condensed consolidated statements of cash flows for the six months ended June 30, 2021 and 2020 are unaudited. The unaudited interim condensed consolidated financial statements have been prepared on the same basis as the audited annual financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for the fair statement of the Company’s financial position as of June 30, 2021, the results of its operations for the three and six months ended June 30, 2021 and 2020, its statements of stockholders’ equity for the three and six months ended June 30, 2021 and 2020 and its statements of cash flows for the six months ended June 30, 2021 and 2020. The financial data and other information disclosed in the notes related to the three and six months ended June 30, 2021 and 2020 are unaudited. The results for the three and six months ended June 30, 2021 and 2020 are not necessarily indicative of results to be expected for the year ending December 31, 2021, any other interim periods, or any future year or period.

The unaudited interim financial statements of the Company included herein have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted from this report, as is permitted by such rules and regulations. These unaudited condensed consolidated financial statements should be read in conjunction with the audited financial statements and the notes thereto contained in the Company’s Annual Report on Form 10-K for the year ended December 31, 2020 filed with the SEC on March 10, 2021.

Use of Estimates

The preparation of financial statements in conformity with GAAP requires management to make estimates, assumptions and judgments that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and the reported amounts of expenses during the reporting periods. Significant estimates, assumptions and judgments reflected in these condensed consolidated financial statements include, but are not limited to, the accrual of research and development expenses and the valuation of stock-based awards. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Actual results could differ from the Company’s estimates.

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Fair Value of Financial Instruments

6 Months Ended

Jun. 30, 2021

Fair Value Disclosures [Abstract]

Fair Value of Financial Instruments

3. Fair Value of Financial Instruments

The following tables show assets measured at fair value on a recurring basis as of June 30, 2021 and December 31, 2020:

	June 30, 2021
(in thousands)	Level 1		Level 2		Level 3
Cash equivalents:
Money market funds	$	13,493	$	—	$	—
Totals	$	13,493	$	—	$	—

	December 31, 2020
(in thousands)	Level 1		Level 2		Level 3
Cash equivalents:
Money market funds	$	13,943	$	—	$	—
Totals	$	13,943	$	—	$	—

There were no liabilities measured at fair value on a recurring basis as of June 30, 2021 and December 31, 2020.

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Accounts Payable, Accrued Expenses and Other

6 Months Ended

Jun. 30, 2021

Payables And Accruals [Abstract]

Accounts Payable, Accrued Expenses and Other

4. Accounts Payable, Accrued Expenses and Other

Accounts payable, accrued expenses and other as of June 30, 2021 and December 31, 2020 consisted of the following:

(in thousands)	June 30, 2021		December 31, 2020
Accounts payable	$	173	$	123
Accrued goods and services		166		194
Accrued clinical trial costs		92		112
Others		341		341
Total accounts payable, accrued expenses and other	$	772	$	770

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Stock-Based Compensation

6 Months Ended

Jun. 30, 2021

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Stock-Based Compensation

5. Stock-Based Compensation

On April 15, 2021, the Company’s Board of Directors adopted the 2021 Incentive Award Plan (the “2021 Plan”) to replace the 2011 Stock Incentive Plan (the “2011 Plan”). The 2021 Plan was approved by the Company’s stockholders at the Company’s Annual Meeting of Stockholders held on June 10, 2021.  The 2021 Plan is administered by the Company’s Board of Directors and permits the Company to grant incentive and non-qualified stock options, stock appreciation rights, restricted stock, restricted stock units and other stock-based awards.

There were 22,000 options granted during the three and six months ended June 30, 2021 under 2021 Plan. The weighted-average grant date fair value per share of stock options granted during the three and six months ended June 30, 2021 was $3.68. There were no options granted during the three and six months ended June 30, 2020. At June 30, 2021, there were 253,000 shares remaining available for grant under the 2021 Plan.

The fair value of stock options granted to employees during the three and six months ended June 30, 2021 was estimated at the date of grant using the following assumptions:

	Three and Six Months Ended June 30,
	2021
Risk-free interest rate		0.73	%
Expected dividend yield	0%
Expected term	5.22 years
Expected volatility	68.48%

The Company recognized stock-based compensation expense of $0.1 million, $0.3 million, $0.5 million and $0.9 million in general and administrative expense during the three and six months ended June 30, 2021 and 2020, respectively.

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Net Loss Per Common Share

6 Months Ended

Jun. 30, 2021

Earnings Per Share [Abstract]

Net Loss Per Common Share

6. Net Loss Per Common Share

Basic net loss per share is calculated by dividing the net loss attributable to Merrimack Pharmaceuticals, Inc. by the weighted-average number of common shares outstanding during the period.

Diluted net loss per share is computed by dividing the net loss attributable to Merrimack Pharmaceuticals, Inc. by the weighted-average number of dilutive common shares outstanding during the period. Dilutive shares outstanding is calculated by adding to the weighted shares outstanding any potential (unissued) shares of common stock from outstanding stock options based on the treasury stock method. Outstanding stock options were not included in the diluted net loss per share calculation because the options were out of the money or to do so would have been antidilutive (i.e., the total proceeds upon exercise would have exceeded the market value of the underlying common shares). In a period when a net loss is reported, all common stock equivalents are excluded from the calculation because they would have an anti-dilutive effect, meaning the loss per share would be reduced. Therefore, in periods where a loss is reported, there is no difference in basic and dilutive loss per share.

Stock options are excluded from the calculation of diluted loss per share because the net loss for the three and six months ended June 30, 2021 and 2020 causes such securities to be anti-dilutive. Outstanding options excluded from the calculation of diluted loss per share for the three and six months ended June 30, 2021 and 2020 are shown in the chart below:

	Three Months Ended June 30,				Six Months Ended June 30,
(in thousands)	2021		2020		2021		2020
Outstanding options to purchase common stock		1,778		1,877		1,778		1,877

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Restructuring Activities

6 Months Ended

Jun. 30, 2021

Restructuring And Related Activities [Abstract]

Restructuring Activities

7. Restructuring Activities

On November 7, 2018, the Company announced that it was implementing a reduction in headcount as part of a corporate restructuring. All the restructuring expenses were paid off as of December 31, 2020.

No additional restructuring expenses was recognized during the three and six months ended June 30, 2020. The Company paid approximately less than $0.1 million and $0.1 million of these restructuring expenses during the three and six months ended June 30, 2020, respectively. No additional restructuring expenses were recognized or paid during the three and six months ended June 30, 2021.

The following table summarizes the charges related to the restructuring activities as of June 30, 2020:

(in thousands)	Accrued Restructuring Expenses at December 31, 2019		Expenses		Less: Payments			Accrued Restructuring Expenses at June 30, 2020
Severance, benefits and related costs due to workforce    reduction	$	66	$	—	$	(51	)	$	15
Totals	$	66	$	—	$	(51	)	$	15

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Recent Accounting Pronouncements

6 Months Ended

Jun. 30, 2021

Accounting Changes And Error Corrections [Abstract]

Recent Accounting Pronouncements

8. Recent Accounting Pronouncements

From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (“FASB”) or other standard setting bodies that the Company adopts as of the specified effective date. Unless otherwise discussed above, the Company does not believe that the adoption of recently issued standards has or may have a material impact on the Company’s condensed consolidated financial statements or disclosures.

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Summary of Significant Accounting Policies (Policies)

6 Months Ended

Jun. 30, 2021

Accounting Policies [Abstract]

Basis of Presentation

Basis of Presentation

The accompanying condensed consolidated financial statements reflect the operations of Merrimack Pharmaceuticals, Inc. and its wholly owned subsidiaries. All intercompany accounts and transactions have been eliminated.

The condensed consolidated financial statements are unaudited and have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”).

The accounting policies followed in the preparation of the interim condensed consolidated financial statements are consistent in all material respects with those presented in Note 1 to the financial statements included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2020.

Unaudited Interim Financial Information

Unaudited Interim Financial Information

The condensed consolidated balance sheet as of December 31, 2020 was derived from audited financial statements, but does not include all disclosures required by GAAP. The condensed consolidated balance sheet as of June 30, 2021, the condensed consolidated statements of operations and comprehensive loss for the three and six months ended June 30, 2021 and 2020, the condensed consolidated statements of stockholders’ equity for the three and six months ended June 30, 2021 and 2020 and the condensed consolidated statements of cash flows for the six months ended June 30, 2021 and 2020 are unaudited. The unaudited interim condensed consolidated financial statements have been prepared on the same basis as the audited annual financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments, necessary for the fair statement of the Company’s financial position as of June 30, 2021, the results of its operations for the three and six months ended June 30, 2021 and 2020, its statements of stockholders’ equity for the three and six months ended June 30, 2021 and 2020 and its statements of cash flows for the six months ended June 30, 2021 and 2020. The financial data and other information disclosed in the notes related to the three and six months ended June 30, 2021 and 2020 are unaudited. The results for the three and six months ended June 30, 2021 and 2020 are not necessarily indicative of results to be expected for the year ending December 31, 2021, any other interim periods, or any future year or period.

The unaudited interim financial statements of the Company included herein have been prepared pursuant to the rules and regulations of the Securities and Exchange Commission (the “SEC”). Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted from this report, as is permitted by such rules and regulations. These unaudited condensed consolidated financial statements should be read in conjunction with the audited financial statements and the notes thereto contained in the Company’s Annual Report on Form 10-K for the year ended December 31, 2020 filed with the SEC on March 10, 2021.

Use of Estimates

Use of Estimates

The preparation of financial statements in conformity with GAAP requires management to make estimates, assumptions and judgments that affect the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the condensed consolidated financial statements and the reported amounts of expenses during the reporting periods. Significant estimates, assumptions and judgments reflected in these condensed consolidated financial statements include, but are not limited to, the accrual of research and development expenses and the valuation of stock-based awards. Estimates are periodically reviewed in light of changes in circumstances, facts and experience. Actual results could differ from the Company’s estimates.

Recent Accounting Pronouncements

From time to time, new accounting pronouncements are issued by the Financial Accounting Standards Board (“FASB”) or other standard setting bodies that the Company adopts as of the specified effective date. Unless otherwise discussed above, the Company does not believe that the adoption of recently issued standards has or may have a material impact on the Company’s condensed consolidated financial statements or disclosures.

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Fair Value of Financial Instruments (Tables)

6 Months Ended

Jun. 30, 2021

Fair Value Disclosures [Abstract]

Summary of Assets Measured at Fair Value on a Recurring Basis

The following tables show assets measured at fair value on a recurring basis as of June 30, 2021 and December 31, 2020:

	June 30, 2021
(in thousands)	Level 1		Level 2		Level 3
Cash equivalents:
Money market funds	$	13,493	$	—	$	—
Totals	$	13,493	$	—	$	—

	December 31, 2020
(in thousands)	Level 1		Level 2		Level 3
Cash equivalents:
Money market funds	$	13,943	$	—	$	—
Totals	$	13,943	$	—	$	—

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Accounts Payable, Accrued Expenses and Other (Tables)

6 Months Ended

Jun. 30, 2021

Payables And Accruals [Abstract]

Schedule of Accounts Payable, Accrued Expenses and Other

Accounts payable, accrued expenses and other as of June 30, 2021 and December 31, 2020 consisted of the following:

(in thousands)	June 30, 2021		December 31, 2020
Accounts payable	$	173	$	123
Accrued goods and services		166		194
Accrued clinical trial costs		92		112
Others		341		341
Total accounts payable, accrued expenses and other	$	772	$	770

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Stock-Based Compensation (Tables)

6 Months Ended

Jun. 30, 2021

Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]

Schedule of Assumptions Used to Calculate Fair Value of Options Granted to Employees

The fair value of stock options granted to employees during the three and six months ended June 30, 2021 was estimated at the date of grant using the following assumptions:

	Three and Six Months Ended June 30,
	2021
Risk-free interest rate		0.73	%
Expected dividend yield	0%
Expected term	5.22 years
Expected volatility	68.48%

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Net Loss Per Common Share (Tables)

6 Months Ended

Jun. 30, 2021

Earnings Per Share [Abstract]

Schedule of Outstanding Options Excluded from Computation of Diluted Loss Per Share

Outstanding options excluded from the calculation of diluted loss per share for the three and six months ended June 30, 2021 and 2020 are shown in the chart below:

	Three Months Ended June 30,				Six Months Ended June 30,
(in thousands)	2021		2020		2021		2020
Outstanding options to purchase common stock		1,778		1,877		1,778		1,877

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Restructuring Activities (Tables)

6 Months Ended

Jun. 30, 2021

Restructuring And Related Activities [Abstract]

Summary of Charges Related to Restructuring Activities

The following table summarizes the charges related to the restructuring activities as of June 30, 2020:

(in thousands)	Accrued Restructuring Expenses at December 31, 2019		Expenses		Less: Payments			Accrued Restructuring Expenses at June 30, 2020
Severance, benefits and related costs due to workforce    reduction	$	66	$	—	$	(51	)	$	15
Totals	$	66	$	—	$	(51	)	$	15

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Nature of the Business - Additional Information (Detail) - USD ($)	1 Months Ended		6 Months Ended
	Mar. 27, 2020	Jul. 12, 2019	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020	Apr. 03, 2017
Summary Of Significant Accounting Policies [Line Items]
Accumulated deficit			$ 545,092,000		$ 543,637,000
Net loss from continuing operations			1,500,000
Cash used in operating activities			582,000	$ (2,984,000)
Cash, cash equivalents and marketable securities			$ 14,900,000
Celator Pharmaceuticals Inc [Member]
Summary Of Significant Accounting Policies [Line Items]
Cash payment received	$ 2,300,000
Reimbursement of expenses	200,000
Transaction expenses	$ 400,000
Ipsen [Member] | Asset Sale Agreement [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Contingent milestone payments receivable						$ 450,000,000.0
Ipsen [Member] | First Line Treatment of Metastatic Adenocarcinoma of Pancreas [Member]
Summary Of Significant Accounting Policies [Line Items]
Contingent milestone payments receivable						225,000,000.0
Ipsen [Member] | After Failure of First Line Chemotherapy [Member]
Summary Of Significant Accounting Policies [Line Items]
Contingent milestone payments receivable						150,000,000.0
Ipsen [Member] | Additional Indication [Member]
Summary Of Significant Accounting Policies [Line Items]
Contingent milestone payments receivable						$ 75,000,000.0
14ner Sale [Member]
Summary Of Significant Accounting Policies [Line Items]
Upfront cash payment received		$ 3,500,000
14ner Sale [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Additional payments receivable on achievement of certain milestone events		54,500,000
14ner Sale [Member] | Achievement of the Primary Endpoint in the First Registrational Clinical Study of Either MM-121 or MM-111 [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Additional payments receivable on achievement of certain milestone events		3,000,000.0
14ner Sale [Member] | Achievement of Various Regulatory Approval and Reimbursement-Based Milestones in the United States, Europe and Japan [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Additional payments receivable on achievement of certain milestone events		16,500,000
14ner Sale [Member] | Achievement Various Cumulative Worldwide Net Sales Targets Between $100.0 million and $300.0 million for MM-121 and MM-111 [Member] | Maximum [Member]
Summary Of Significant Accounting Policies [Line Items]
Additional payments receivable on achievement of certain milestone events		35,000,000.0
Cumulative worldwide net sales target		$ 300,000,000.0

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Fair Value of Financial Instruments - Summary of Assets Measured at Fair Value on a Recurring Basis (Detail) - Recurring Basis [Member] - Level 1 [Member] - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	$ 13,493	$ 13,943
Money Market Funds [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Cash equivalents	$ 13,493	$ 13,943

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Fair Value of Financial Instruments - Additional Information (Detail) - USD ($)	Jun. 30, 2021	Dec. 31, 2020
Recurring Basis [Member]
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Liabilities measured at fair value	$ 0	$ 0

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Accounts Payable, Accrued Expenses and Other - Schedule of Accounts Payable, Accrued Expenses and Other (Detail) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Payables And Accruals [Abstract]
Accounts payable	$ 173	$ 123
Accrued goods and services	166	194
Accrued clinical trial costs	92	112
Others	341	341
Total accounts payable, accrued expenses and other	$ 772	$ 770

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Stock-Based Compensation - Additional Information (Detail) - USD ($) $ / shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Options, Granted	22,000	0	22,000	0
Weighted Average Exercise Price	$ 3,680		$ 3,680
General and Administrative Expense [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Allocated Share Based Compensation Expense	$ 100,000	$ 500,000	$ 300,000	$ 900,000
Stock Incentive Plan 2021 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock available for grant (in shares)	253,000		253,000

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Stock-Based Compensation - Schedule of Assumptions Used to Calculate Fair Value of Options Granted to Employees (Detail)	6 Months Ended
	Jun. 30, 2021
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Risk-free interest rate	0.73%
Expected dividend yield	0.00%
Expected term	5 years 2 months 19 days
Expected volatility	68.48%

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Net Loss Per Common Share - Schedule of Outstanding Options Excluded from Computation of Diluted Income (Loss) Per Share (Detail) - shares shares in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Outstanding Options to Purchase Common Stock [Member]
Antidilutive Securities Excluded From Computation Of Earnings Per Share [Line Items]
Outstanding options to purchase common stock	1,778	1,877	1,778	1,877

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Restructuring Activities - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Restructuring Cost And Reserve [Line Items]
Restructuring expenses	$ 0	$ 0	$ 0	$ 0
Payments for restructuring				$ 51,000
Maximum [Member]
Restructuring Cost And Reserve [Line Items]
Payments for restructuring		$ 100,000
November 2018 Corporate Restructuring [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring activity, announcement date			Nov. 07, 2018

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Restructuring Activities - Summary of Charges Related to Restructuring Activities (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Restructuring Cost And Reserve [Line Items]
Accrued Restructuring Expenses				$ 66,000
Expenses	$ 0	$ 0	$ 0	0
Less: Payments				(51,000)
Accrued Restructuring Expenses		15,000		15,000
Severance, Benefits and Related Costs Due to Workforce Reduction [Member]
Restructuring Cost And Reserve [Line Items]
Accrued Restructuring Expenses				66,000
Less: Payments				(51,000)
Accrued Restructuring Expenses		$ 15,000		$ 15,000