10-Q

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 10-Q

(Mark One)

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

For the quarterly period ended March 31, 2023

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

For the transition period from             to            

COMMISSION FILE NUMBER 001-35558

CARDIFF ONCOLOGY, INC.

(Exact Name of registrant as specified in its charter)

Delaware	27-2004382
(State or other jurisdiction of incorporation or organization)	(I.R.S. Employer Identification No.)
11055 Flintkote Avenue, San Diego, California	92121
(Address of principal executive offices)	(Zip Code)
(858) 952-7570
(Registrant’s telephone number, including area code)

Title of each class:	Trading Symbol(s)	Name of each exchange on which registered:
Common Stock	CRDF	Nasdaq Capital Market

Indicate by check mark whether the issuer (1) filed all reports required to be filed by Section 13 or 15(d) of the Exchange Act 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 and posted on its corporate Web site, if any, every Interactive Data File required to be submitted and posted 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 and post such files). Yes ☒   No ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, smaller reporting company, or an emerging growth company. See 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 April 27, 2023, the issuer had 44,677,169 shares of Common Stock issued and outstanding.

CARDIFF ONCOLOGY, INC.

Table of Contents

		Page
PART I	FINANCIAL INFORMATION
Item 1.	Financial Statements (unaudited)
	Condensed Balance Sheets	3
	Condensed Statements of Operations	4
	Condensed Statements of Comprehensive Loss	5
	Condensed Statements of Stockholders’ Equity	6
	Condensed Statements of Cash Flows	7
	Notes to Condensed Financial Statements	8
Item 2.	Management’s Discussion and Analysis of Financial Condition and Results of Operations	17
Item 3.	Quantitative and Qualitative Disclosures About Market Risk	22
Item 4.	Controls and Procedures	22
PART II	OTHER INFORMATION
Item 1.	Legal Proceedings	23
Item 1A.	Risk Factors	23
Item 2.	Unregistered Sales of Equity Securities and Use of Proceeds	23
Item 3.	Defaults Upon Senior Securities	23
Item 4.	Mine Safety Disclosures	23
Item 5.	Other Information	23
Item 6.	Exhibits	23
SIGNATURES

2

PART I. FINANCIAL INFORMATION

ITEM 1. FINANCIAL STATEMENTS

CARDIFF ONCOLOGY, INC. 

CONDENSED BALANCE SHEETS

(in thousands, except par value)

(Unaudited)

	March 31, 2023		December 31, 2022
Assets
Current assets:
Cash and cash equivalents	$	15,017	$	16,347
Short-term investments	81,951		88,920
Accounts receivable and unbilled receivable	676		771
Prepaid expenses and other current assets	4,109		5,246
Total current assets	101,753		111,284
Property and equipment, net	1,320		1,269
Operating lease right-of-use assets	2,115		2,251
Other assets	1,361		1,387
Total Assets	$	106,549	$	116,191
Liabilities and Stockholders’ Equity
Current liabilities:
Accounts payable	$	2,914	$	1,956
Accrued liabilities	4,555		5,177
Operating lease liabilities	679		675
Total current liabilities	8,148		7,808
Operating lease liabilities, net of current portion	1,898		2,040
Total Liabilities	10,046		9,848
Commitments and contingencies (Note 7)
Stockholders’ equity
Preferred stock, 20,000 shares authorized; Series A Convertible Preferred Stock liquidation preference $1,050 and $1,044 at March 31, 2023 and December 31, 2022, respectively (Note 6)	—		—
Common stock, $0.0001 par value, 150,000 shares authorized; 44,677 and 44,677 shares issued and outstanding at March 31, 2023 and December 31, 2022, respectively	4		4
Additional paid-in capital	405,898		404,834
Accumulated other comprehensive loss	(76)		(395)
Accumulated deficit	(309,323)		(298,100)
Total stockholders’ equity	96,503		106,343
Total liabilities and stockholders’ equity	$	106,549	$	116,191

See accompanying notes to the unaudited condensed financial statements.

3

CARDIFF ONCOLOGY, INC.

CONDENSED STATEMENTS OF OPERATIONS

(in thousands, except per share amounts)

(Unaudited)

	Three Months Ended March 31,
	2023		2022
Royalty revenues	$	83	$	74
Costs and expenses:
Research and development	9,052		7,208
Selling, general and administrative	3,083		3,940
Total operating expenses	12,135		11,148
Loss from operations	(12,052)		(11,074)
Other income (expense), net:
Interest income, net	940		130
Other income (expense), net	(111)		(49)
Total other income (expense), net	829		81
Net loss	(11,223)		(10,993)
Preferred stock dividend payable on Series A Convertible Preferred Stock	(6)		(6)
Net loss attributable to common stockholders	$	(11,229)	$	(10,999)
Net loss per common share — basic and diluted	$	(0.25)	$	(0.25)
Weighted-average shares outstanding — basic and diluted	44,677		43,231

See accompanying notes to the unaudited condensed financial statements.

4

CARDIFF ONCOLOGY, INC.

CONDENSED STATEMENTS OF COMPREHENSIVE LOSS

(in thousands)

(Unaudited)

	Three Months Ended March 31,
	2023		2022
Net loss	$	(11,223)	$	(10,993)
Other comprehensive loss:
Unrealized gain (loss) on securities available-for-sale	319		(606)
Total comprehensive loss	(10,904)		(11,599)
Preferred stock dividend payable on Series A Convertible Preferred Stock	(6)		(6)
Comprehensive loss attributable to common stockholders	$	(10,910)	$	(11,605)

See accompanying notes to the unaudited condensed financial statements.

5

CARDIFF ONCOLOGY, INC.

CONDENSED STATEMENTS OF STOCKHOLDERS’ EQUITY

(in thousands)

(Unaudited)

	Preferred Stock Shares	Preferred Stock Amount		Common Stock Shares	Common Stock Amount		Additional Paid-In Capital		Accumulated Other Comprehensive Loss		Accumulated Deficit		Total Stockholders’ Equity
Balance, January 1, 2023	61	$	—	44,677	$	4	$	404,834	$	(395)	$	(298,100)	$	106,343
Stock-based compensation	—	—		—	—		1,064		—		—		1,064
Other comprehensive gain	—	—		—	—		—		319		—		319
Net loss	—	—		—	—		—		—		(11,223)		(11,223)
Balance, March 31, 2023	61	$	—	44,677	$	4	$	405,898	$	(76)	$	(309,323)	$	96,503

	Preferred Stock Shares	Preferred Stock Amount		Common Stock Shares	Common Stock Amount		Additional Paid-In Capital		Service Receivable		Accumulated Other Comprehensive Loss		Accumulated Deficit		Total Stockholders’ Equity
Balance, January 1, 2022	716	$	1	41,964	$	4	$	400,503	$	(139)	$	(142)	$	(259,810)	$	140,417
Stock-based compensation	—	—		—	—		1,152		—		—		—		1,152
Other comprehensive loss	—	—		—	—		—		—		(606)		—		(606)
Issuance of common stock upon conversion of Series E Convertible Preferred Stock	(328)	(1)		1,342	—		—		—		—		—		(1)
Preferred stock dividend	—	—		—	—		—		—		—		(6)		(6)
Release of clinical trial funding commitment	—	—		—	—		—		139		—		—		139
Net loss	—	—		—	—		—		—		—		(10,993)		(10,993)
Balance, March 31, 2022	388	$	—	43,306	$	4	$	401,655	$	—	$	(748)	$	(270,809)	$	130,102

See accompanying notes to the unaudited condensed financial statements.

6

CARDIFF ONCOLOGY, INC. 

CONDENSED STATEMENTS OF CASH FLOWS

(in thousands)

(Unaudited)

	Three Months Ended March 31,
	2023		2022
Operating activities
Net loss	$	(11,223)	$	(10,993)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	90		31
Stock-based compensation expense	1,064		1,152
Amortization of premiums (discounts) on short-term investments	(163)		346
Release of clinical trial funding commitment	—		139
Changes in operating assets and liabilities:
Other assets	26		51
Accounts receivable and unbilled receivable	95		88
Prepaid expenses and other assets	1,251		(1,141)
Operating lease right-of-use assets	136		136
Accounts payable and accrued expenses	203		—
Operating lease liabilities	(138)		(16)
Other liabilities	—		(42)
Net cash used in operating activities	(8,659)		(10,249)
Investing activities:
Capital expenditures	(8)		(171)
Maturities of short-term investments	42,983		38,217
Purchases of short-term investments	(37,327)		(36,773)
Sales of short-term investments	1,681		17,085
Net cash provided by investing activities	7,329		18,358
Financing activities:
Net cash provided by financing activities	—		—
Net change in cash and cash equivalents	(1,330)		8,109
Cash and cash equivalents—Beginning of period	16,347		11,943
Cash and cash equivalents—End of period	$	15,017	$	20,052
Supplementary disclosure of cash flow activity:
Cash paid for taxes	$	—	$	1
Supplemental disclosure of non-cash investing and financing activities:
Acquisition of property and equipment included in accounts payable and accrued expenses	$	133	$	27

See accompanying notes to the unaudited condensed financial statements.

7

CARDIFF ONCOLOGY, INC. 

NOTES TO CONDENSED FINANCIAL STATEMENTS

(Unaudited)

1. Organization and Basis of Presentation

Business Organization and Overview

Cardiff Oncology, Inc. (“Cardiff Oncology” or the “Company”) headquartered in San Diego, California, is a clinical-stage biotechnology company leveraging Polo-like Kinase 1 (“PLK1”) inhibition to develop novel therapies across a range of cancers. The Company’s lead asset is onvansertib, a PLK1 inhibitor that is being evaluated in combination with standard-of-care therapies in clinical programs targeting indications such as KRAS/NRAS-mutated metastatic colorectal cancer, metastatic pancreatic cancer, as well as investigator-initiated trials in triple negative breast cancer and small cell lung cancer. These programs and the Company’s broader development strategy are designed to target tumor vulnerabilities in order to overcome treatment resistance and deliver superior clinical benefit compared to the standard-of-care alone. The Company's common stock is listed on the Nasdaq Capital Market under the ticker symbol "CRDF".

Basis of Presentation

The accompanying unaudited interim condensed financial statements of Cardiff Oncology have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) and the rules and regulations of the Securities and Exchange Commission (“SEC”) related to a quarterly report on Form 10-Q. Certain information and note disclosures normally included in annual financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to those rules and regulations. The unaudited interim condensed financial statements reflect all adjustments consisting of normal recurring adjustments which, in the opinion of management, are necessary for a fair statement of the Company’s financial position and the results of its operations and cash flows for the periods presented. The unaudited condensed balance sheet at December 31, 2022, has been derived from the audited financial statements at that date but does not include all of the information and disclosures required by GAAP for annual financial statements. The operating results presented in these unaudited interim condensed financial statements are not necessarily indicative of the results that may be expected for any future periods. These unaudited interim condensed financial statements should be read in conjunction with the audited financial statements and the notes thereto for the year ended December 31, 2022, included in the Company’s annual report on Form 10-K filed with the SEC on March 2, 2023.

Liquidity

The Company has incurred net losses since its inception and has negative operating cash flows. As of March 31, 2023, the Company had $97.0 million in cash, cash equivalents and short-term investments and believes it has sufficient cash to meet its funding requirements for at least the next 12 months following the issuance date of these financial statements.

For the foreseeable future, the Company expects to continue to incur losses and require additional capital to further advance its clinical trial programs and support its other operations. The Company cannot be certain that additional funding will be available on acceptable terms, or at all. To the extent that the Company can raise additional funds by issuing equity securities, the Company’s stockholders may experience additional dilution.

2. Summary of Significant Accounting Policies

During the three months ended March 31, 2023, there have been no changes to the Company’s significant accounting policies as described in its Annual Report on Form 10-K for the fiscal year ended December 31, 2022.

Net Loss Per Share

Basic and diluted net loss per common share is determined by dividing net loss applicable to common stockholders by the weighted-average common shares outstanding during the period. Preferred dividends are included in net loss attributable to common stockholders in the computation of basic and diluted earnings per share.

8

The following table sets forth the outstanding potentially dilutive securities that have been excluded in the calculation of diluted net loss per share because their effect was anti-dilutive:

	March 31,
	2023	2022
Options to purchase Common Stock	6,396,895	5,467,611
Warrants to purchase Common Stock	4,296,472	4,490,159
Series A Convertible Preferred Stock	877	877
Series E Convertible Preferred Stock	—	1,342,250
	10,694,244	11,300,897

Recent Accounting Pronouncement Not Yet Adopted

In August 2020, the FASB issued ASU No. 2020-06 ("ASU 2020-06"), Debt - Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging - Contracts in Entity’s Own Equity (Subtopic 815-40) (“ASU 2020-06”). ASU 2020-06 eliminates the beneficial conversion and cash conversion accounting models for convertible instruments. It also amends the accounting for certain contracts in an entity’s own equity that are currently accounted for as derivatives because of specific settlement provisions. In addition, ASU 2020-06 modifies how particular convertible instruments and certain contracts that may be settled in cash or shares impact the diluted EPS computation. The amendments in this update are effective for public business entities for fiscal years beginning after December 15, 2021 (or December 15, 2023, for companies who meet the SEC definition of Smaller Reporting Companies), and interim periods within those fiscal years. The amendment is to be adopted through either a fully retrospective or modified retrospective method of transition. Early adoption is permitted. The Company is currently evaluating the impact of this standard on its financial statements and related disclosures, and will adopt this standard on January 1, 2024.

3. Fair Value Measurements

The following table presents the Company’s assets and liabilities that are measured and recognized at fair value on a recurring basis classified under the appropriate level of the fair value hierarchy as of March 31, 2023, and December 31, 2022:

	Fair Value Measurements at March 31, 2023
(in thousands)	Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Assets:
Money market fund	$	14,158	$	—	$	—	$	14,158
Total included in cash and cash equivalents	14,158		—		—		14,158
Available for sale investments:
Certificate of deposit	—		13,925		—		13,925
Corporate debt securities	—		32,828		—		32,828
Commercial paper	—		10,398		—		10,398
U.S. government agencies	—		7,842				7,842
U.S. treasury securities	16,958		—		—		16,958
Total available for sale investments (1)	16,958		64,993		—		81,951
Total assets measured at fair value on a recurring basis	$	31,116	$	64,993	$	—	$	96,109

9

	Fair Value Measurements at December 31, 2022
(in thousands)	Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Assets:
Money market fund	$	15,722	$	—	$	—	$	15,722
Total included in cash and cash equivalents	15,722		—		—		15,722
Available for sale investments:
Certificate of deposit	—		16,023		—		16,023
Corporate debt securities	—		49,535		—		49,535
Commercial paper	—		13,187		—		13,187
U.S. government agencies	—		2,288		—		2,288
U.S. treasury securities	7,887		—		—		7,887
Total available for sale investments (1)	7,887		81,033		—		88,920
Total assets measured at fair value on a recurring basis	$	23,609	$	81,033	$	—	$	104,642

(1) Included in short-term investments in the accompanying balance sheets.

The Company’s policy is to recognize transfers between levels of the fair value hierarchy on the date of the event or change in circumstances that caused the transfer. There were no transfers into or out of Level 3 during the three months ended March 31, 2023.

4. Supplementary Balance Sheet Information

10

Investments available for sale

Investments available for sale consist of the following:

	As of March 31, 2023
(in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Market Value
Maturity less than 1 year:
Certificate of deposit	$	13,964	$	1	$	(40)	$	13,925
Corporate debt securities	22,258		4		(118)		22,144
Commercial paper	10,402		3		(7)		10,398
U.S. government agencies	4,049		4		—		4,053
Total maturity less than 1 year	50,673		12		(165)		50,520
Maturity 1 to 2 years:
Corporate debt securities	10,687		24		(27)		10,684
U.S. government agencies	3,781		8		—		3,789
U.S. treasury securities	16,886		72		—		16,958
Total maturity 1 to 2 years	31,354		104		(27)		31,431
Total short-term investments	$	82,027	$	116	$	(192)	$	81,951

	As of December 31, 2022
(in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Market Value
Maturity less than 1 year:
Certificate of deposit	$	16,101	$	3	$	(81)	$	16,023
Corporate debt securities	44,806		8		(275)		44,539
Commercial paper	13,203		4		(20)		13,187
Non U.S. government	2,284		4		—		2,288
U.S. treasury securities	7,905		—		(18)		7,887
Total maturity less than 1 year	84,299		19		(394)		83,924
Maturity 1 to 2 years:
Corporate debt securities	5,016		1		(21)		4,996
Total maturity 1 to 2 years	5,016		1		(21)		4,996
Total short-term investments	$	89,315	$	20	$	(415)	$	88,920

We periodically review our portfolio of debt securities to determine if any investment is impaired due to credit loss or other potential valuation concerns. For debt securities where the fair value of the investment is less than the amortized cost basis, we have assessed at the individual security level for various quantitative factors including, but not limited to, the nature of the investments, changes in credit ratings, interest rate fluctuations, industry analyst reports, and the severity of impairment. Unrealized losses in investments available for sale debt securities at March 31, 2023, were substantially due to increases in interest rates, not due to increased credit risks associated with specific securities. Accordingly, we have not recorded an allowance for credit losses. It is not more likely than not that we will be required to sell the investments before recovery of their amortized cost bases, which may be at maturity.

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Investments available for sale that have been in a continuous unrealized loss position for greater than one-year consist of the following:

	As of March 31, 2023
(in thousands)	Fair Market Value		Gross Unrealized Loss
Corporate debt securities	$	8,151	$	(58)

Property and equipment

Property and equipment consist of the following:

 

(in thousands)	As of March 31, 2023		As of December 31, 2022
Furniture and office equipment	$	1,066	$	1,066
Leasehold improvements	2,560		2,560
Laboratory equipment	1,153		1,056
	4,779		4,682
Less—accumulated depreciation and amortization	(3,459)		(3,413)
Property and equipment, net	$	1,320	$	1,269

Accrued Liabilities

Accrued liabilities consisted of the following:

(in thousands)	As of March 31, 2023		As of December 31, 2022
Accrued compensation	$	983	$	1,849
Clinical trials	2,709		2,333
Research agreements and services	571		509
Director fees	125		125
Patent, license and other fees	59		24
Other accrued liabilities	108		337
Total accrued liabilities	$	4,555	$	5,177

5. Leases

 As a lessee, the Company’s current leases include its master facility lease and immaterial equipment leases, all of which are considered operating leases.

Master Facility Lease

The Company currently leases office and lab space in San Diego that expires on February 28, 2027. The lease currently requires monthly payments of approximately $61,000 per month with 3% annual escalation.

The components of lease expense were as follows:

	Three Months Ended March 31,
(in thousands)	2023		2022
Operating lease cost	$	183	$	191
Net operating lease cost	$	183	$	191

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Supplemental balance sheet information related to leases was as follows:

(in thousands)	As of March 31, 2023			As of December 31, 2022
Operating lease ROU assets	$	2,115		$	2,251
Current operating lease liabilities	$	679		$	675
Non-current operating lease liabilities	1,898			2,040
Total operating lease liabilities	$	2,577		$	2,715
Weighted-average remaining lease term–operating leases	3.9 years			4.2 years
Weighted-average discount rate–operating leases	7.0		%	7.0		%

Supplemental cash flow and other information related to leases was as follows:

	Three Months Ended March 31,
(in thousands)	2023		2022
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$	185	$	70

Total remaining annual commitments under non-cancelable lease agreements for each of the years ended December 31 are as follows:

(in thousands)
Year Ending December 31,	Operating Leases
2023 (excluding the three months ended March 31, 2023)	$	491
2024	754
2025	775
2026	796
Thereafter	136
Total future minimum lease payments	2,952
Less imputed interest	(375)
Total	$	2,577

6. Stockholders’ Equity

Stock Options

Stock-based compensation expense related to Cardiff Oncology equity awards have been recognized in operating results as follows:

	Three Months Ended March 31,
(in thousands)	2023		2022
Included in research and development expense	$	394	$	335
Included in selling, general and administrative expense	670		817
Total stock-based compensation expense	$	1,064	$	1,152

The unrecognized compensation cost related to non-vested stock options outstanding at March 31, 2023, net of estimated forfeitures, was $10.1 million, which is expected to be recognized over a weighted-average remaining vesting period of 2.7 years. The weighted-average remaining contractual term of outstanding options as of March 31, 2023, was approximately

13

8.5 years. The total fair value of stock options vested during the three months ended March 31, 2023 and 2022, were $1.9 million and $1,000, respectively.

The estimated fair value of stock option awards was determined on the date of grant using the Black-Scholes option valuation model with the following weighted-average assumptions during the following periods indicated:

	Three Months Ended March 31,
	2023		2022
Risk-free interest rate	3.58	%	1.84	%
Dividend yield	0	%	0	%
Expected volatility of Cardiff Oncology common stock	110	%	106	%
Expected term(1)	5.3 years		6.0 years

(1)The expected term for options granted after January 1, 2023 is estimated based on the Company's historical employee data. Prior to January 1, 2023, the Company used the "simplified method" to estimate expected term.

A summary of stock option activity and changes in stock options outstanding is presented below:

	Total Options	Weighted-Average Exercise Price Per Share		Intrinsic Value
Balance outstanding, December 31, 2022	5,069,458	$	5.92	$	19,322
Granted	1,806,008	$	1.73
Canceled / Forfeited	(1,725)	$	7.98
Expired	(476,846)	$	6.93
Balance outstanding, March 31, 2023	6,396,895	$	4.66	$	34,107
Exercisable at March 31, 2023	2,427,304	$	6.57	$	20,517
Vested and expected to vest at March 31, 2023	6,187,656	$	4.73	$	33,160

2021 Equity Incentive Plan

In June 2021 the Company's stockholders approved the 2021 Omnibus Equity Incentive Plan ("2021 Plan"). The number of authorized shares in the 2021 Plan is equal to the sum of (i) 3,150,000 shares, plus (ii) the number of shares of Common Stock reserved, but unissued under the 2014 Plan; and (iii) the number of shares of Common Stock underlying forfeited awards under the 2014 Plan. On June 9, 2022, the shareholders approved an increase of shares authorized in the 2021 Plan to 5,150,000 from 3,150,000. As of March 31, 2023, there were 2,180,898 shares available for issuance under the 2021 Plan.

2014 Equity Incentive Plan

Subsequent to the adoption of the 2021 Plan, no additional equity awards can be made under the terms of the 2014 Plan.

Inducement Grants

The Company issues equity awards to certain new employees as inducement grants outside of its 2021 Plan. As of March 31, 2023, an aggregate of 1,345,208 shares were issuable upon the exercise of inducement grant stock options approved by the Company.

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Warrants

A summary of warrant activity and changes in warrants outstanding, including both liability and equity classifications is presented below:

	Total Warrants	Weighted-Average Exercise Price Per Share		Weighted-Average Remaining Contractual Term
Balance outstanding, December 31, 2022	4,360,968	$	5.33	2.1 years
Expired	(64,496)	$	101.52
Balance outstanding, March 31, 2023	4,296,472	$	3.89	1.8 years

Preferred Stock

A summary of our Company's classes of preferred stock is presented below:

				Shares outstanding
Class	Par value		Shares designated	As of March 31, 2023	As of December 31, 2022
Series A Convertible Preferred Stock	$	0.001	277,100	60,600	60,600
Series B Convertible Preferred Stock	$	0.001	8,860	—	—
Series C Convertible Preferred Stock	$	0.001	200,000	—	—
Series D Convertible Preferred Stock	$	0.0001	154,670	—	—
Series E Convertible Preferred Stock	$	0.001	865,824	—	—

7. Commitments and Contingencies

Executive Agreements

Certain executive agreements provide for severance payments in case of terminations without cause or certain change of control scenarios.

Research and Development Agreements

In March 2017, the Company entered into a license agreement with Nerviano which granted the Company development and commercialization rights to NMS-1286937, which Cardiff Oncology refers to as onvansertib. Terms of the agreement also provide for the Company to pay development and commercial milestones, and royalties based on sales volume. These potential development milestones include: (a) dosing of the first subject in the first Phase III Clinical Trial for the first Product, a registration enabling Phase II Clinical Trial, or after completion of a Phase II Clinical Trial that is used as the basis for an NDA submission; and (b) upon filing of the first NDA or equivalent for the first product candidate. During the three months ended March 31, 2023 and 2022 no milestone or royalty payments were made.

The Company is a party to various agreements under which it licenses technology on an exclusive basis in the field of oncology therapeutics. These agreements include License fees, Royalties and Milestone payments. The Company also has a legacy license agreement in the field of oncology diagnostics under which royalty payments are due. These royalty payments are calculated as a percent of revenue. For the three months ended March 31, 2023 and 2022, payments have not been material.

Litigation

Cardiff Oncology does not believe that it has legal liabilities that are probable or reasonably possible that require either accrual or disclosure. From time to time, the Company may become involved in various lawsuits and legal proceedings that arise in the ordinary course of business. Litigation is subject to inherent uncertainties, and an adverse result in matters may arise

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from time to time that may harm the Company’s business. As of the date of this report, management believes that there are no claims against the Company, which it believes will result in a material adverse effect on the Company’s business or financial condition.

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ITEM 2. MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

Forward-Looking Statements

This Quarterly Report on Form 10-Q includes forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended (the “Securities Act”) and Section 21E of the Securities Exchange Act of 1934, as amended (the “Exchange Act”). All statements other than statements of historical facts contained in this Quarterly Report, including statements regarding the future financial position, business strategy and plans and objectives of management for future operations, are forward-looking statements. The words “believe,” “may,” “will,” “estimate,” “continue,” “anticipate,” “intend,” “should,” “plan,” “expect,” and similar expressions, as they relate to us, are intended to identify forward-looking statements. We have based these forward-looking statements largely on current expectations and projections about future events and financial trends that we believe may affect our financial condition, results of operations, business strategy and financial needs. These forward-looking statements are subject to a number of risks, uncertainties and assumptions.

In addition, our business and financial performance may be affected by the factors that are discussed under “Risk Factors” in the Annual Report on Form 10-K for the year ended December 31, 2022, filed on March 2, 2023. Moreover, we operate in a very competitive and rapidly changing environment. New risk factors emerge from time to time and it is not possible for us to predict all risk factors, nor can we assess the impact of all factors on our business or the extent to which any factor, or combination of factors, may cause actual results to differ materially from those contained in any forward-looking statements.

You should not rely upon forward-looking statements as predictions of future events. We cannot assure you that the events and circumstances reflected in the forward-looking statements will be achieved or occur. Although we believe that the expectations reflected in the forward-looking statements are reasonable, we cannot guarantee future results, levels of activity, performance or achievements.

The following discussion and analysis is qualified in its entirety by, and should be read in conjunction with, the more detailed information set forth in the financial statements and the notes thereto appearing elsewhere in this Quarterly Report on Form 10-Q. This discussion should not be construed to imply that the results discussed herein will necessarily continue into the future, or that any conclusion reached herein will necessarily be indicative of actual operating results in the future. Such discussion represents only the best present assessment of our management.

Overview

We are a clinical-stage biotechnology company leveraging PLK1 inhibition, a well-validated oncology drug target, to develop novel therapies across a range of cancers with the greatest unmet medical need. Our goal is to target tumor vulnerabilities with treatment combinations of onvansertib, our oral and highly selective PLK1 inhibitor, and standard of care ("SoC") therapeutics. We are focusing our clinical program in indications such as KRAS/NRAS-mutated metastatic colorectal cancer ("mCRC") and metastatic pancreatic ductal adenocarcinoma ("mPDAC"), as well as in investigator-initiated trials in triple negative breast cancer ("TNBC") and small cell lung cancer ("SCLC"). Our clinical development programs incorporate tumor genomics and biomarker assays to refine assessment of patient response to treatment.

Our Lead Drug Candidate, Onvansertib

Onvansertib is an oral, small molecule drug candidate that is highly specific for PLK1 inhibition with a 24-hour half-life.

We believe the attributes of onvansertib described below, as well as clinical evidence of favorable safety and efficacy, with expected on-target, easy to manage and reversible side effects, may prove beneficial in addressing clinical therapeutic needs across a variety of cancers:

•Onvansertib is highly potent and highly selective against the PLK1 enzyme (IC50 = 2nM; IC50 is the concentration for 50% inhibition), compared to prior PLK1 inhibitors that were pan-inhibitors of several PLK targets. Low or no activity of onvansertib was observed on a panel of 63 kinases (IC50>500 nM), including the PLK members PLK2 and PLK3 (IC50>10,000 nM);

•Onvansertib is orally bioavailable, allowing for relative ease and flexibility of dosing.

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•Onvansertib has a relatively short drug half-life of 24 hours, allowing for flexible dosing and scheduling which has shown favorable safety and tolerability across multiple clinical trials;

In vitro studies have shown synergistic effects when onvansertib was administered in combination with different cytotoxic agents including microtubule-targeting agents, topoisomerase 1 inhibitors, antimetabolites, alkylating agents, proteasome inhibitors, kinase inhibitors, PARP inhibitors, BCL-2 inhibitors, and androgen biosynthesis inhibitors.

In addition, in vivo combination studies have confirmed the positive results obtained in vitro and synergistic effects have been observed in xenograft models of onvansertib in combination with irinotecan, 5-fluorouracil ("5-FU"), abiraterone, PARP inhibitors, venetoclax, and paclitaxel, while additive effects in combination with cytarabine or bevacizumab have been demonstrated. Combining onvansertib with standard of care cancer agents provides opportunities for synergy with many cancer therapies.

There are five ongoing clinical trials of onvansertib: two trials (TROV-054 and ONSEMBLE) in second line treatment in patients with KRAS-mutated Metastatic Colorectal Cancer ("mCRC"), one trial in second line treatment in patients with Metastatic Pancreatic Ductal Adenocarcinoma ("mPDAC"), and two investigator-initiated trials in patients with unresectable locally advanced or metastatic Triple Negative Breast Cancer ("TNBC") and relapsed Small Cell Lung Cancer ("SCLC").

Phase 1b/2 Clinical Trial in KRAS-mutated mCRC

TROV-054 is a Phase 1b/2 open-label multi-center clinical trial of onvansertib in combination with standard of care FOLFIRI and bevacizumab for the second line treatment of patients with KRAS-mutated mCRC, which is being conducted at seven clinical trial sites across the U.S. - USC Norris Comprehensive Cancer Center, The Mayo Clinic Cancer Centers (Arizona, Minnesota, and Florida), Kansas University Medical Center, Inova Schar Cancer Institute and CARTI Cancer Center. This trial completed enrollment in October 2022.

The primary objectives of this trial are to evaluate the Dose-Limiting Toxicities ("DLTs"), maximum tolerated dose ("MTD") and recommended Phase 2 dose ("RP2D") of onvansertib in combination with FOLFIRI and bevacizumab (Phase 1b) and to continue to assess the safety and preliminary efficacy of onvansertib in combination with FOLFIRI and bevacizumab patients with KRAS-mutated mCRC (Phase 2).

The scientific rationale for this clinical trial is based on the two key principles of synthetic lethality and synergy, with the objective of demonstrating a proof-of-concept of clinical benefit within this Phase 1b/2 trial. Synthetic lethality refers to a critical vulnerability to tumor cell death by way of PLK1 inhibition within CRC tumor cells harboring KRAS mutations versus KRAS wild-type isogenic cells. Synergy occurs when the combination of multiple drugs results in an unexpected greater activity than an expected additive effect of the individual drugs. Onvansertib in combination with two DNA-damaging agents, irinotecan and 5-FU (two components of FOLFIRI), demonstrated synergy in colorectal cancer cell lines and both combinations have demonstrated significantly greater tumor growth inhibition than either drug alone in CRC in vivo models. We believe this synergy occurs because PLK1 can promote the repair of DNA damage caused by chemotherapeutic agents and by inhibiting PLK1, onvansertib leaves damaged tumor cells unable to repair DNA damage from chemotherapy and then replicate. For more information, please visit NCT03829410 at www.clinicialtrials.gov.

Data presented on September 12, 2022, provided an update of the ongoing TROV-054 Phase 1b/2 single arm clinical trial in KRAS-mutated metastatic colorectal cancer:

•Objective response rate ("ORR") across all evaluable patients was 35%, with 17 of 48 evaluable patients achieving an objective response. Responses have been observed across multiple KRAS variants;

•Median duration of response ("mDoR") across all evaluable patients was 11.7 months (95% confidence interval ("CI"): 8.9 – not reached);

•Median progression free survival ("mPFS") across all evaluable patients was 9.3 months (95% CI: 7.6 – 13.5). Historical control trials of different drug combinations, including the standard-of-care ("SOC") of FOLFIRI with bevacizumab, in similar patient populations have shown ORR and mPFS of 5 – 13% and ~4.5 – 5.7 months, respectively.

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•A subgroup analysis of patients who were bevacizumab naïve when they entered 2nd line therapy vs patients who had received prior bevacizumab in 1st line therapy showed that patients who were bevacizumab naïve (n=13) had an ORR of 69% and mPFS of 13.5 months, which is well above historical controls. In contrast, patients previously treated with bevacizumab (n=35) had an ORR of 23% and mPFS of 7.8 months.

Phase 2 Randomized Clinical Trial in KRAS-mutated mCRC (the ONSEMBLE trial)

The ONSEMBLE trial (CRDF-003), is a Phase 2 open-label, randomized multi-center clinical trial of onvansertib in combination with standard of care FOLFIRI and bevacizumab for the second line treatment of patients with KRAS/NRAS-mutated mCRC. The trial is currently open for enrollment and will be conducted at approximately 40 clinical trial sites across the U.S.

The primary objectives of the ONSEMBLE trial is to evaluate onvansertib’s safety and efficacy in combination with the standard-of-care FOLFIRI/bevacizumab regimen in patients with second-line KRAS/NRAS-mutated mCRC. The trial is expected to enroll approximately 150 patients who will be randomized 1:1:1 to receive standard of care alone, standard of care plus 20 mg onvansertib, or standard of care plus 30 mg onvansertib, with onvansertib administered on days 1-5 and 15-19 of 28-day treatment cycles.

The primary endpoint of the trial is objective response rate, defined as a tumor reduction in size of at least 30% as per RECIST 1.1. Progression-free survival and duration of response will be key secondary endpoints. The trial was activated during the fourth quarter of 2022, with topline data anticipated in the second-half of 2024. For more information, please visit NCT05593328 at www.clinicialtrials.gov.

The first patient was dosed in the ONSEMBLE trial during March 2023.

Phase 2 Clinical Trial in mPDAC

CRDF-001 is a Phase 2 open-label multi-center clinical trial of onvansertib in combination with nanoliposomal irinotecan (Onivyde®), leucovorin, and fluorouracil for second line treatment of patients with mPDAC, which is being conducted at six clinical trial sites across the U.S. – The Mayo Clinic Cancer Centers (Arizona, Minnesota, and Florida), Kansas University Medical Center, Inova Schar Cancer Institute, and the University of Nebraska Medical Center. The first patient was dosed in June 2021.

The objective of this trial is to assess the safety and preliminary efficacy of onvansertib in combination with nanoliposomal irinotecan (Onyvide®), 5-FU and leucovorin as a second-line treatment in patients with mPDAC who have failed 1st line gemcitabine-based therapy. The trial is expected to enroll approximately 45 patients. For more information, please visit NCT04752696 at www.clinicialtrials.gov.

Preliminary data presented on September 12, 2022 provided an update of the ongoing CRDF-001 Phase 2 open label clinical trial in mPDAC:

•Preliminary data from 5 evaluable patients showed 1 patient achieving an initial partial response ("PR") and 3 patients achieving stable disease ("SD");

•The 4 patients achieving SD or PR remain on study; the fifth evaluable patient discontinued treatment due to disease progression and an additional 3 patients remain on study awaiting their first post-baseline scan;

•Additional data is expected in mid-2023.

Phase 1b/2 Investigator-Initiated Clinical Trial in TNBC

A single-arm, Phase 1b/2 trial of onvansertib in combination with paclitaxel in patients with unresectable locally advanced or metastatic TNBC is open for enrollment at Dana Farber Cancer Institute ("DFCI"). In Phase 1b, approximately 14-16 patients will be treated with different doses of onvansertib in combination with a fixed dose of paclitaxel to determine the maximum tolerated dose and RP2D of onvansertib. In Phase 2, approximately 34 patients will be treated with the selected onvansertib RP2D in combination with paclitaxel.

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The primary endpoint of Phase 2 of the trial is ORR, with PFS included as a secondary endpoint. Preliminary data from the trial are expected in the fourth-quarter of 2023 or first-quarter of 2024. For more information, please visit NCT05383196 at www.clinicialtrials.gov.

Phase 2 Investigator-Initiated Clinical Trial in SCLC

A single-arm, two-stage, Phase 2 trial of onvansertib monotherapy in patients with relapsed SCLC is open for enrollment at the University of Pittsburgh Medical Center ("UPMC"). The trial is designed to enroll 15 patients in Stage 1, with the study proceeding to Stage 2 if 2 or more Stage 1 patients achieve an objective response. Stage 2 is designed to enroll an additional 20 patients. The primary endpoint of the trial is ORR, while key secondary endpoints include PFS and overall survival. Preliminary data from the trial are expected in mid-2023. For more information, please visit NCT05450965 at www.clinicialtrials.gov.

Recent Updates

Appointment of Chief Medical Officer

On February 2, 2023, we announced the appointment of Fairooz Kabbinavar, M.D., FACP, as Chief Medical Officer.

Scientific Advisory Board

On March 6, 2023, we formally introduced our Scientific Advisory Board ("SAB"). The SAB is comprised of a distinguished group of academic and industry experts who bring depth and breadth of knowledge in oncology drug development, clinical trial design, translational science and clinical research. In most cases, these individuals have been advising us for several years and will now collectively serve a critical role as we advance the clinical development of onvansertib. We anticipate that over time the membership of the SAB may expand to add additional expertise in new indications or stages of clinical development.

Critical Accounting Policies

Our accounting policies are described in ITEM 7. MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS of our Annual Report on Form 10-K as of and for the year ended December 31, 2022, filed with the SEC on March 2, 2023. There have been no changes to our critical accounting policies since December 31, 2022.

Three Months Ended March 31, 2023 and 2022

Revenues

Total revenues were $83,000 for the three months ended March 31, 2023, as compared to $74,000 for the same period in 2022. Revenues are from our sales-based or usage-based royalties on other intellectual property licenses, unrelated to onvansertib. Revenue recognition of the royalty depends on the timing and overall sales activities of the licensees.

Research and Development Expenses

Research and development expenses consisted of the following:

	Three Months Ended March 31,
(in thousands)	2023		2022		Increase (Decrease)
Salaries and staff costs	$	1,374	$	1,061	$	313
Stock-based compensation	394		335		59
Clinical trials, outside services, and lab supplies	6,845		5,517		1,328
Facilities and other	439		295		144
Total research and development	$	9,052	$	7,208	$	1,844

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Research and development expenses increased by $1.8 million for the three months ended March 31, 2023, compared to the same period in 2022. The overall increase in expenses was primarily due to costs associated with clinical programs and outside service costs related to the development of our lead drug candidate, onvansertib. Salaries and staff costs increased primarily due to the expansion of our clinical operations team (research and development average headcount grew by 25% over the comparative period). The increase in facilities and other is primarily due to increased allocation of facilities cost resulting from headcount growth compared to the prior period.

Selling, General and Administrative Expenses

Selling, general and administrative expenses consisted of the following:

	Three Months Ended March 31,
(in thousands)	2023		2022		Increase (Decrease)
Salaries and staff costs	$	799	$	861	$	(62)
Stock-based compensation	670		817		(147)
Outside services and professional fees	1,021		1,605		(584)
Facilities and other	593		657		(64)
Total selling, general and administrative	$	3,083	$	3,940	$	(857)

Selling, general and administrative expenses decreased by $0.9 million for the three months ended March 31, 2023, compared to the same period in 2022. Outside services decreased due to the completion of strategic valuation consulting related to our lead drug candidate, onvansertib, during the prior period. Stock-based compensation decreased due to a change in the timing of stock option grants to our board of directors. Facilities and other costs decreased primarily due to lower insurance costs as compared to the prior period.

Net Loss

Net loss and per share amounts were as follows:

	Three Months Ended March 31,
(in thousands, except per share amounts)	2023		2022		Increase (Decrease)
Net loss	$	(11,223)	$	(10,993)	$	230
Preferred stock dividend	(6)		(6)		—
Net loss attributable to common shareholders	$	(11,229)	$	(10,999)	$	230
Net loss per common share — basic and diluted	$	(0.25)	$	(0.25)	$	—
Weighted average shares outstanding — basic and diluted	44,677		43,231		1,446

The $0.2 million increase in net loss attributable to common shareholders was primarily the result of an increase in operating expenses for the three months ended March 31, 2023, compared to the same period in 2022. There was no change in basic and diluted net loss per share with the addition of 1.4 million shares of common stock issued from April 1, 2022 through March 31, 2023.

LIQUIDITY AND CAPITAL RESOURCES

Net cash used in operating activities for the three months ended March 31, 2023, was $8.7 million, compared to $10.2 million for the three months ended March 31, 2022. Our use of cash was primarily a result of the net loss of $11.2 million for the three months ended March 31, 2023, adjusted for non-cash items related to stock-based compensation of $1.1 million. The net change in our operating assets and liabilities was primarily the result of decreasing cash used in operations of $1.6 million. At our current and anticipated level of operating loss, we expect to continue to incur an operating cash outflow for the next several years.

Net cash provided by investing activities was $7.3 million primarily related to sales and maturities in excess of purchases of marketable securities for the three months ended March 31, 2023, compared to net cash used in investing activities

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of $18.4 million primarily related to sales and maturities in excess of purchases of marketable securities during the same period in 2022.

Net cash provided in financing activities was $0 for the three months ended March 31, 2023, and 2022.

As of March 31, 2023, and December 31, 2022, we had working capital of $93.6 million and $103.5 million, respectively.

We have incurred net losses since our inception and have negative operating cash flows. As of March 31, 2023, we had $97.0 million in cash, cash equivalents and short-term investments and we believe we have sufficient cash to meet our funding requirements for at least the next 12 months following the issuance date of this Quarterly Report on Form 10-Q. Based on our current projections we expect that our capital resources are sufficient to fund our operations into 2025.

Our drug development efforts are in their early stages, and we cannot make estimates of the costs or the time that our development efforts will take to complete, or the timing and amount of revenues related to the sale of our drug candidates. The risk of completion of any program is high because of the many uncertainties involved in developing new drug candidates to market, including the long duration of clinical testing, the specific performance of proposed products under stringent clinical trial protocols, extended regulatory approval and review cycles, our ability to raise additional capital, the nature and timing of research and development expenses, and competing technologies being developed by organizations with significantly greater resources.

For the foreseeable future, we expect to continue to incur losses and require additional capital to further advance our clinical trial programs and support our other operations. We cannot be certain that additional funding will be available on acceptable terms, or at all. To the extent that we can raise additional funds by issuing equity securities, our stockholders may experience additional dilution.

ITEM 3. QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

Not applicable.

ITEM 4. CONTROLS AND PROCEDURES

Evaluation of Disclosure Controls and Procedures

We have performed an evaluation under the supervision and with the participation of our management, including our principal executive officer (CEO) and principal financial officer (CFO), of the effectiveness of our disclosure controls and procedures, as defined in Rule 13a-15(e) and 15d-15(e) under the Securities Exchange Act of 1934, as amended (the “Exchange Act”). Based on that evaluation, our principal executive officer and principal financial officer concluded that our disclosure controls and procedures were effective as of March 31, 2023, to provide reasonable assurance that information required to be disclosed by us in the reports filed or submitted by us under the Exchange Act is recorded, processed, summarized and reported within the time periods specified in the SEC’s rules and forms.

Our disclosure controls and procedures are designed to provide reasonable assurance of achieving their objectives as specified above. Management does not expect, however, that our disclosure controls and procedures will prevent or detect all errors and fraud. Any control system, no matter how well designed and operated, is based upon certain assumptions and can provide only reasonable, not absolute, assurance that its objectives will be met. Further, no evaluation of controls can provide absolute assurance that misstatements due to error or fraud will not occur or that all control issues and instances of fraud, if any, within our company have been detected.

Changes in Internal Control over Financial Reporting

There was no change in our internal control over financial reporting during the three months ended March 31, 2023, that materially affected, or is reasonably likely to materially affect, our internal control over financial reporting.

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PART II.  OTHER INFORMATION

ITEM 1. LEGAL PROCEEDINGS

None.

ITEM 1A. RISK FACTORS

There have been no material changes from the risk factors disclosed in our Form 10-K for the year ended December 31, 2022.

ITEM 2. UNREGISTERED SALES OF EQUITY SECURITIES AND USE OF PROCEEDS

None.

ITEM 3. DEFAULTS UPON SENIOR SECURITIES

None.

ITEM 4. MINE SAFETY DISCLOSURES

Not applicable.

ITEM 5. OTHER INFORMATION

None.

ITEM 6. EXHIBITS

Exhibit Number	Description of Exhibit
31.1	Certification of Principal Executive Officer required by Rule 13a-14(a)/15d-14(a) under the Exchange Act.
31.2	Certification of Principal Financial Officer required by Rule 13a-14(a)/15d-14(a) under the Exchange Act.
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
101.CAL	Inline XBRL Taxonomy Extension Calculation Linkbase
101.LAB	Inline XBRL Taxonomy Extension Labels Linkbase
101.PRE	Inline XBRL Taxonomy Extension Presentation Linkbase
101.DEF	Inline XBRL Taxonomy Extension Definition Linkbase
104	Cover Page Interactive Data File - the cover page from the Registrant’s Quarterly Report on Form 10-Q for the quarter ended March 31, 2023, is formatted in Inline XBRL

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SIGNATURES

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

	CARDIFF ONCOLOGY, INC.
May 4, 2023	By:	/s/ Mark Erlander
		Mark Erlander
		Chief Executive Officer
	CARDIFF ONCOLOGY, INC.
May 4, 2023	By:	/s/ James Levine
		James Levine
		Chief Financial Officer

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EX-31.1

Exhibit 31.1

CERTIFICATION OF PRINCIPAL EXECUTIVE OFFICER

I, Mark Erlander, certify that:

1.I have reviewed this quarterly report on Form 10-Q of Cardiff Oncology, Inc. (the “Registrant”);

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.

May 4, 2023	/s/ Mark Erlander
	Mark Erlander
	Chief Executive Officer

EX-31.2

Exhibit 31.2

CERTIFICATION OF PRINCIPAL FINANCIAL OFFICER

I, James Levine, certify that:

1.I have reviewed this quarterly report on Form 10-Q of Cardiff Oncology, Inc. (the “Registrant”);

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.

May 4, 2023	/s/ James Levine
	James Levine
	Chief Financial Officer

EX-32.1

Exhibit 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

In connection with the Quarterly Report of Cardiff Oncology, Inc. (the “Company”) on Form 10-Q for the three months ended March 31, 2023 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Mark Erlander, Chief Executive Officer of the Company, certify, pursuant to 18 U.S.C. § 1350, as adopted pursuant to § 906 of the Sarbanes-Oxley Act of 2002, that:

(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.

May 4, 2023	/s/ Mark Erlander
	Mark Erlander
	Chief Executive Officer

EX-32.2

Exhibit 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

In connection with the Quarterly Report of Cardiff Oncology, Inc. (the “Company”) on Form 10-Q for the three months ended March 31, 2023 as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, James Levine, Chief Financial Officer of the Company, certify, pursuant to 18 U.S.C. § 1350, as adopted pursuant to § 906 of the Sarbanes-Oxley Act of 2002, that:

(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.

May 4, 2023	/s/ James Levine
	James Levine
	Chief Financial Officer

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Cover Page - shares	3 Months Ended
	Mar. 31, 2023	Apr. 27, 2023
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Transition Report	false
Document Period End Date	Mar. 31, 2023
Entity File Number	001-35558
Entity Registrant Name	CARDIFF ONCOLOGY, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	27-2004382
Entity Address, Address Line One	11055 Flintkote Avenue
Entity Address, City or Town	San Diego
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	92121
City Area Code	858
Local Phone Number	952-7570
Title of 12(b) Security	Common Stock
Trading Symbol	CRDF
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		44,677,169
Entity Central Index Key	0001213037
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q1

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CONDENSED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 15,017	$ 16,347
Short-term investments	81,951	88,920
Accounts receivable and unbilled receivable	676	771
Prepaid expenses and other current assets	4,109	5,246
Total current assets	101,753	111,284
Property and equipment, net	1,320	1,269
Operating lease right-of-use assets	2,115	2,251
Other assets	1,361	1,387
Total Assets	106,549	116,191
Current liabilities:
Accounts payable	2,914	1,956
Accrued liabilities	4,555	5,177
Operating lease liabilities	679	675
Total current liabilities	8,148	7,808
Operating lease liabilities, net of current portion	1,898	2,040
Total Liabilities	10,046	9,848
Commitments and contingencies (Note 7)
Stockholders’ equity
Preferred stock, 20,000 shares authorized; Series A Convertible Preferred Stock liquidation preference $1,050 and $1,044 at March 31, 2023 and December 31, 2022, respectively (Note 6)	0	0
Common stock, $0.0001 par value, 150,000 shares authorized; 44,677 and 44,677 shares issued and outstanding at March 31, 2023 and December 31, 2022, respectively	4	4
Additional paid-in capital	405,898	404,834
Accumulated other comprehensive loss	(76)	(395)
Accumulated deficit	(309,323)	(298,100)
Total stockholders’ equity	96,503	106,343
Total liabilities and stockholders’ equity	$ 106,549	$ 116,191

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CONDENSED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Preferred stock, shares authorized (in shares)	20,000,000	20,000,000
Liquidation preference	$ 1,050	$ 1,044
Common stock, par value (in USD per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	150,000,000	150,000,000
Common stock, shares issued (in shares)	44,677,000	44,677,000
Common stock, shares outstanding (in shares)	44,677,000	44,677,000

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CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Income Statement [Abstract]
Royalties	$ 83	$ 74
Costs and expenses:
Research and development	9,052	7,208
Selling, general and administrative	3,083	3,940
Total operating expenses	12,135	11,148
Loss from operations	(12,052)	(11,074)
Interest income, net	940	130
Other income (expense), net	(111)	(49)
Total other income (expense), net	829	81
Net loss	(11,223)	(10,993)
Preferred stock dividend payable on Series A Convertible Preferred Stock	(6)	(6)
Net loss attributable to common stockholders	$ (11,229)	$ (10,999)
Net loss per common share - basic (in dollars per share)	$ (0.25)	$ (0.25)
Net loss per common share - diluted (in dollars per share)	$ (0.25)	$ (0.25)
Weighted-average shares outstanding - basic (in shares)	44,677	43,231
Weighted-average shares outstanding - diluted (in shares)	44,677	43,231

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CONDENSED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Statement of Comprehensive Income [Abstract]
Net loss	$ (11,223)	$ (10,993)
Other comprehensive loss:
Unrealized gain (loss) on securities available-for-sale	319	(606)
Total comprehensive loss	(10,904)	(11,599)
Preferred stock dividend payable on Series A Convertible Preferred Stock	(6)	(6)
Comprehensive loss attributable to common stockholders	$ (10,910)	$ (11,605)

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CONDENSED STATEMENT OF STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Preferred Stock	Common Stock	Additional Paid-In Capital	Service Receivable	Accumulated Other Comprehensive Loss	Accumulated Deficit
Balance, beginning (in shares) at Dec. 31, 2021		716	41,964
Balance, beginning at Dec. 31, 2021	$ 140,417	$ 1	$ 4	$ 400,503	$ (139)	$ (142)	$ (259,810)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	1,152			1,152
Other comprehensive gain (loss)	(606)					(606)
Issuance of common stock upon conversion of Series E Convertible Preferred Stock (in shares)		(328)	1,342
Issuance of common stock upon conversion of Series E Convertible Preferred Stock	(1)	$ (1)
Preferred stock dividend	(6)						(6)
Release of clinical trial funding commitment	139				139
Net loss	(10,993)						(10,993)
Balance, ending (in shares) at Mar. 31, 2022		388	43,306
Balance, ending at Mar. 31, 2022	130,102	$ 0	$ 4	401,655	$ 0	(748)	(270,809)
Balance, beginning (in shares) at Dec. 31, 2022		61	44,677
Balance, beginning at Dec. 31, 2022	106,343	$ 0	$ 4	404,834		(395)	(298,100)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	1,064			1,064
Other comprehensive gain (loss)	319					319
Net loss	(11,223)						(11,223)
Balance, ending (in shares) at Mar. 31, 2023		61	44,677
Balance, ending at Mar. 31, 2023	$ 96,503	$ 0	$ 4	$ 405,898		$ (76)	$ (309,323)

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CONDENSED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Operating activities
Net loss	$ (11,223)	$ (10,993)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	90	31
Stock-based compensation expense	1,064	1,152
Amortization of premiums (discounts) on short-term investments	(163)	346
Release of clinical trial funding commitment	0	139
Changes in operating assets and liabilities:
Other assets	26	51
Accounts receivable and unbilled receivable	95	88
Prepaid expenses and other assets	1,251	(1,141)
Operating lease right-of-use assets	136	136
Accounts payable and accrued expenses	203	0
Operating lease liabilities	(138)	(16)
Other liabilities	0	(42)
Net cash used in operating activities	(8,659)	(10,249)
Investing activities:
Capital expenditures	(8)	(171)
Maturities of short-term investments	42,983	38,217
Purchases of short-term investments	(37,327)	(36,773)
Sales of short-term investments	1,681	17,085
Net cash provided by investing activities	7,329	18,358
Financing activities:
Net cash provided by financing activities	0	0
Net change in cash and cash equivalents	(1,330)	8,109
Cash and cash equivalents—Beginning of period	16,347	11,943
Cash and cash equivalents—End of period	15,017	20,052
Supplementary disclosure of cash flow activity:
Cash paid for taxes	0	1
Supplemental disclosure of non-cash investing and financing activities:
Acquisition of property and equipment included in accounts payable and accrued expenses	$ 133	$ 27

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Organization and Basis of Presentation

3 Months Ended

Mar. 31, 2023

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Organization and Basis of Presentation

Organization and Basis of Presentation

Business Organization and Overview

Cardiff Oncology, Inc. (“Cardiff Oncology” or the “Company”) headquartered in San Diego, California, is a clinical-stage biotechnology company leveraging Polo-like Kinase 1 (“PLK1”) inhibition to develop novel therapies across a range of cancers. The Company’s lead asset is onvansertib, a PLK1 inhibitor that is being evaluated in combination with standard-of-care therapies in clinical programs targeting indications such as KRAS/NRAS-mutated metastatic colorectal cancer, metastatic pancreatic cancer, as well as investigator-initiated trials in triple negative breast cancer and small cell lung cancer. These programs and the Company’s broader development strategy are designed to target tumor vulnerabilities in order to overcome treatment resistance and deliver superior clinical benefit compared to the standard-of-care alone. The Company's common stock is listed on the Nasdaq Capital Market under the ticker symbol "CRDF".

Basis of Presentation

The accompanying unaudited interim condensed financial statements of Cardiff Oncology have been prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) and the rules and regulations of the Securities and Exchange Commission (“SEC”) related to a quarterly report on Form 10-Q. Certain information and note disclosures normally included in annual financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to those rules and regulations. The unaudited interim condensed financial statements reflect all adjustments consisting of normal recurring adjustments which, in the opinion of management, are necessary for a fair statement of the Company’s financial position and the results of its operations and cash flows for the periods presented. The unaudited condensed balance sheet at December 31, 2022, has been derived from the audited financial statements at that date but does not include all of the information and disclosures required by GAAP for annual financial statements. The operating results presented in these unaudited interim condensed financial statements are not necessarily indicative of the results that may be expected for any future periods. These unaudited interim condensed financial statements should be read in conjunction with the audited financial statements and the notes thereto for the year ended December 31, 2022, included in the Company’s annual report on Form 10-K filed with the SEC on March 2, 2023.

Liquidity

The Company has incurred net losses since its inception and has negative operating cash flows. As of March 31, 2023, the Company had $97.0 million in cash, cash equivalents and short-term investments and believes it has sufficient cash to meet its funding requirements for at least the next 12 months following the issuance date of these financial statements.

For the foreseeable future, the Company expects to continue to incur losses and require additional capital to further advance its clinical trial programs and support its other operations. The Company cannot be certain that additional funding will be available on acceptable terms, or at all. To the extent that the Company can raise additional funds by issuing equity securities, the Company’s stockholders may experience additional dilution.

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Summary of Significant Accounting Policies

3 Months Ended

Mar. 31, 2023

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

Summary of Significant Accounting Policies

During the three months ended March 31, 2023, there have been no changes to the Company’s significant accounting policies as described in its Annual Report on Form 10-K for the fiscal year ended December 31, 2022.

Net Loss Per Share

Basic and diluted net loss per common share is determined by dividing net loss applicable to common stockholders by the weighted-average common shares outstanding during the period. Preferred dividends are included in net loss attributable to common stockholders in the computation of basic and diluted earnings per share.

The following table sets forth the outstanding potentially dilutive securities that have been excluded in the calculation of diluted net loss per share because their effect was anti-dilutive:

	March 31,
	2023	2022
Options to purchase Common Stock	6,396,895	5,467,611
Warrants to purchase Common Stock	4,296,472	4,490,159
Series A Convertible Preferred Stock	877	877
Series E Convertible Preferred Stock	—	1,342,250
	10,694,244	11,300,897

Recent Accounting Pronouncement Not Yet Adopted

In August 2020, the FASB issued ASU No. 2020-06 ("ASU 2020-06"), Debt - Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging - Contracts in Entity’s Own Equity (Subtopic 815-40) (“ASU 2020-06”). ASU 2020-06 eliminates the beneficial conversion and cash conversion accounting models for convertible instruments. It also amends the accounting for certain contracts in an entity’s own equity that are currently accounted for as derivatives because of specific settlement provisions. In addition, ASU 2020-06 modifies how particular convertible instruments and certain contracts that may be settled in cash or shares impact the diluted EPS computation. The amendments in this update are effective for public business entities for fiscal years beginning after December 15, 2021 (or December 15, 2023, for companies who meet the SEC definition of Smaller Reporting Companies), and interim periods within those fiscal years. The amendment is to be adopted through either a fully retrospective or modified retrospective method of transition. Early adoption is permitted. The Company is currently evaluating the impact of this standard on its financial statements and related disclosures, and will adopt this standard on January 1, 2024.

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Fair Value Measurements

3 Months Ended

Mar. 31, 2023

Fair Value Disclosures [Abstract]

Fair Value Measurements

Fair Value Measurements

The following table presents the Company’s assets and liabilities that are measured and recognized at fair value on a recurring basis classified under the appropriate level of the fair value hierarchy as of March 31, 2023, and December 31, 2022:

	Fair Value Measurements at March 31, 2023
(in thousands)	Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Assets:
Money market fund	$	14,158	$	—	$	—	$	14,158
Total included in cash and cash equivalents	14,158		—		—		14,158
Available for sale investments:
Certificate of deposit	—		13,925		—		13,925
Corporate debt securities	—		32,828		—		32,828
Commercial paper	—		10,398		—		10,398
U.S. government agencies	—		7,842				7,842
U.S. treasury securities	16,958		—		—		16,958
Total available for sale investments (1)	16,958		64,993		—		81,951
Total assets measured at fair value on a recurring basis	$	31,116	$	64,993	$	—	$	96,109

	Fair Value Measurements at December 31, 2022
(in thousands)	Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Assets:
Money market fund	$	15,722	$	—	$	—	$	15,722
Total included in cash and cash equivalents	15,722		—		—		15,722
Available for sale investments:
Certificate of deposit	—		16,023		—		16,023
Corporate debt securities	—		49,535		—		49,535
Commercial paper	—		13,187		—		13,187
U.S. government agencies	—		2,288		—		2,288
U.S. treasury securities	7,887		—		—		7,887
Total available for sale investments (1)	7,887		81,033		—		88,920
Total assets measured at fair value on a recurring basis	$	23,609	$	81,033	$	—	$	104,642

(1) Included in short-term investments in the accompanying balance sheets.

The Company’s policy is to recognize transfers between levels of the fair value hierarchy on the date of the event or change in circumstances that caused the transfer. There were no transfers into or out of Level 3 during the three months ended March 31, 2023

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Supplementary Balance Sheet Information

3 Months Ended

Mar. 31, 2023

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Supplementary Balance Sheet Information

Supplementary Balance Sheet Information

Investments available for sale

Investments available for sale consist of the following:

	As of March 31, 2023
(in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Market Value
Maturity less than 1 year:
Certificate of deposit	$	13,964	$	1	$	(40)	$	13,925
Corporate debt securities	22,258		4		(118)		22,144
Commercial paper	10,402		3		(7)		10,398
U.S. government agencies	4,049		4		—		4,053
Total maturity less than 1 year	50,673		12		(165)		50,520
Maturity 1 to 2 years:
Corporate debt securities	10,687		24		(27)		10,684
U.S. government agencies	3,781		8		—		3,789
U.S. treasury securities	16,886		72		—		16,958
Total maturity 1 to 2 years	31,354		104		(27)		31,431
Total short-term investments	$	82,027	$	116	$	(192)	$	81,951

	As of December 31, 2022
(in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Market Value
Maturity less than 1 year:
Certificate of deposit	$	16,101	$	3	$	(81)	$	16,023
Corporate debt securities	44,806		8		(275)		44,539
Commercial paper	13,203		4		(20)		13,187
Non U.S. government	2,284		4		—		2,288
U.S. treasury securities	7,905		—		(18)		7,887
Total maturity less than 1 year	84,299		19		(394)		83,924
Maturity 1 to 2 years:
Corporate debt securities	5,016		1		(21)		4,996
Total maturity 1 to 2 years	5,016		1		(21)		4,996
Total short-term investments	$	89,315	$	20	$	(415)	$	88,920

We periodically review our portfolio of debt securities to determine if any investment is impaired due to credit loss or other potential valuation concerns. For debt securities where the fair value of the investment is less than the amortized cost basis, we have assessed at the individual security level for various quantitative factors including, but not limited to, the nature of the investments, changes in credit ratings, interest rate fluctuations, industry analyst reports, and the severity of impairment. Unrealized losses in investments available for sale debt securities at March 31, 2023, were substantially due to increases in interest rates, not due to increased credit risks associated with specific securities. Accordingly, we have not recorded an allowance for credit losses. It is not more likely than not that we will be required to sell the investments before recovery of their amortized cost bases, which may be at maturity.

Investments available for sale that have been in a continuous unrealized loss position for greater than one-year consist of the following:

	As of March 31, 2023
(in thousands)	Fair Market Value		Gross Unrealized Loss
Corporate debt securities	$	8,151	$	(58)

Property and equipment

Property and equipment consist of the following:

 

(in thousands)	As of March 31, 2023		As of December 31, 2022
Furniture and office equipment	$	1,066	$	1,066
Leasehold improvements	2,560		2,560
Laboratory equipment	1,153		1,056
	4,779		4,682
Less—accumulated depreciation and amortization	(3,459)		(3,413)
Property and equipment, net	$	1,320	$	1,269

Accrued Liabilities

Accrued liabilities consisted of the following:

(in thousands)	As of March 31, 2023		As of December 31, 2022
Accrued compensation	$	983	$	1,849
Clinical trials	2,709		2,333
Research agreements and services	571		509
Director fees	125		125
Patent, license and other fees	59		24
Other accrued liabilities	108		337
Total accrued liabilities	$	4,555	$	5,177

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Leases

3 Months Ended

Mar. 31, 2023

Leases [Abstract]

Leases

Leases

 As a lessee, the Company’s current leases include its master facility lease and immaterial equipment leases, all of which are considered operating leases.

Master Facility Lease

The Company currently leases office and lab space in San Diego that expires on February 28, 2027. The lease currently requires monthly payments of approximately $61,000 per month with 3% annual escalation.

The components of lease expense were as follows:

	Three Months Ended March 31,
(in thousands)	2023		2022
Operating lease cost	$	183	$	191
Net operating lease cost	$	183	$	191

Supplemental balance sheet information related to leases was as follows:

(in thousands)	As of March 31, 2023			As of December 31, 2022
Operating lease ROU assets	$	2,115		$	2,251
Current operating lease liabilities	$	679		$	675
Non-current operating lease liabilities	1,898			2,040
Total operating lease liabilities	$	2,577		$	2,715
Weighted-average remaining lease term–operating leases	3.9 years			4.2 years
Weighted-average discount rate–operating leases	7.0		%	7.0		%

Supplemental cash flow and other information related to leases was as follows:

	Three Months Ended March 31,
(in thousands)	2023		2022
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$	185	$	70

Total remaining annual commitments under non-cancelable lease agreements for each of the years ended December 31 are as follows:

(in thousands)
Year Ending December 31,	Operating Leases
2023 (excluding the three months ended March 31, 2023)	$	491
2024	754
2025	775
2026	796
Thereafter	136
Total future minimum lease payments	2,952
Less imputed interest	(375)
Total	$	2,577

Leases

Leases

 As a lessee, the Company’s current leases include its master facility lease and immaterial equipment leases, all of which are considered operating leases.

Master Facility Lease

The Company currently leases office and lab space in San Diego that expires on February 28, 2027. The lease currently requires monthly payments of approximately $61,000 per month with 3% annual escalation.

The components of lease expense were as follows:

	Three Months Ended March 31,
(in thousands)	2023		2022
Operating lease cost	$	183	$	191
Net operating lease cost	$	183	$	191

Supplemental balance sheet information related to leases was as follows:

(in thousands)	As of March 31, 2023			As of December 31, 2022
Operating lease ROU assets	$	2,115		$	2,251
Current operating lease liabilities	$	679		$	675
Non-current operating lease liabilities	1,898			2,040
Total operating lease liabilities	$	2,577		$	2,715
Weighted-average remaining lease term–operating leases	3.9 years			4.2 years
Weighted-average discount rate–operating leases	7.0		%	7.0		%

Supplemental cash flow and other information related to leases was as follows:

	Three Months Ended March 31,
(in thousands)	2023		2022
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$	185	$	70

Total remaining annual commitments under non-cancelable lease agreements for each of the years ended December 31 are as follows:

(in thousands)
Year Ending December 31,	Operating Leases
2023 (excluding the three months ended March 31, 2023)	$	491
2024	754
2025	775
2026	796
Thereafter	136
Total future minimum lease payments	2,952
Less imputed interest	(375)
Total	$	2,577

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Stockholders' Equity

3 Months Ended

Mar. 31, 2023

Stockholders' Equity Note [Abstract]

Stockholders' Equity

Stockholders’ Equity

Stock Options

Stock-based compensation expense related to Cardiff Oncology equity awards have been recognized in operating results as follows:

	Three Months Ended March 31,
(in thousands)	2023		2022
Included in research and development expense	$	394	$	335
Included in selling, general and administrative expense	670		817
Total stock-based compensation expense	$	1,064	$	1,152

The unrecognized compensation cost related to non-vested stock options outstanding at March 31, 2023, net of estimated forfeitures, was $10.1 million, which is expected to be recognized over a weighted-average remaining vesting period of 2.7 years. The weighted-average remaining contractual term of outstanding options as of March 31, 2023, was approximately

8.5 years. The total fair value of stock options vested during the three months ended March 31, 2023 and 2022, were $1.9 million and $1,000, respectively.

The estimated fair value of stock option awards was determined on the date of grant using the Black-Scholes option valuation model with the following weighted-average assumptions during the following periods indicated:

	Three Months Ended March 31,
	2023		2022
Risk-free interest rate	3.58	%	1.84	%
Dividend yield	0	%	0	%
Expected volatility of Cardiff Oncology common stock	110	%	106	%
Expected term(1)	5.3 years		6.0 years

(1)The expected term for options granted after January 1, 2023 is estimated based on the Company's historical employee data. Prior to January 1, 2023, the Company used the "simplified method" to estimate expected term.

A summary of stock option activity and changes in stock options outstanding is presented below:

	Total Options	Weighted-Average Exercise Price Per Share		Intrinsic Value
Balance outstanding, December 31, 2022	5,069,458	$	5.92	$	19,322
Granted	1,806,008	$	1.73
Canceled / Forfeited	(1,725)	$	7.98
Expired	(476,846)	$	6.93
Balance outstanding, March 31, 2023	6,396,895	$	4.66	$	34,107
Exercisable at March 31, 2023	2,427,304	$	6.57	$	20,517
Vested and expected to vest at March 31, 2023	6,187,656	$	4.73	$	33,160

2021 Equity Incentive Plan

In June 2021 the Company's stockholders approved the 2021 Omnibus Equity Incentive Plan ("2021 Plan"). The number of authorized shares in the 2021 Plan is equal to the sum of (i) 3,150,000 shares, plus (ii) the number of shares of Common Stock reserved, but unissued under the 2014 Plan; and (iii) the number of shares of Common Stock underlying forfeited awards under the 2014 Plan. On June 9, 2022, the shareholders approved an increase of shares authorized in the 2021 Plan to 5,150,000 from 3,150,000. As of March 31, 2023, there were 2,180,898 shares available for issuance under the 2021 Plan.

2014 Equity Incentive Plan

Subsequent to the adoption of the 2021 Plan, no additional equity awards can be made under the terms of the 2014 Plan.

Inducement Grants

The Company issues equity awards to certain new employees as inducement grants outside of its 2021 Plan. As of March 31, 2023, an aggregate of 1,345,208 shares were issuable upon the exercise of inducement grant stock options approved by the Company.

Warrants

A summary of warrant activity and changes in warrants outstanding, including both liability and equity classifications is presented below:

	Total Warrants	Weighted-Average Exercise Price Per Share		Weighted-Average Remaining Contractual Term
Balance outstanding, December 31, 2022	4,360,968	$	5.33	2.1 years
Expired	(64,496)	$	101.52
Balance outstanding, March 31, 2023	4,296,472	$	3.89	1.8 years

Preferred Stock

A summary of our Company's classes of preferred stock is presented below:

				Shares outstanding
Class	Par value		Shares designated	As of March 31, 2023	As of December 31, 2022
Series A Convertible Preferred Stock	$	0.001	277,100	60,600	60,600
Series B Convertible Preferred Stock	$	0.001	8,860	—	—
Series C Convertible Preferred Stock	$	0.001	200,000	—	—
Series D Convertible Preferred Stock	$	0.0001	154,670	—	—
Series E Convertible Preferred Stock	$	0.001	865,824	—	—

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Commitments and Contingencies

3 Months Ended

Mar. 31, 2023

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

Commitments and Contingencies

Executive Agreements

Certain executive agreements provide for severance payments in case of terminations without cause or certain change of control scenarios.

Research and Development Agreements

In March 2017, the Company entered into a license agreement with Nerviano which granted the Company development and commercialization rights to NMS-1286937, which Cardiff Oncology refers to as onvansertib. Terms of the agreement also provide for the Company to pay development and commercial milestones, and royalties based on sales volume. These potential development milestones include: (a) dosing of the first subject in the first Phase III Clinical Trial for the first Product, a registration enabling Phase II Clinical Trial, or after completion of a Phase II Clinical Trial that is used as the basis for an NDA submission; and (b) upon filing of the first NDA or equivalent for the first product candidate. During the three months ended March 31, 2023 and 2022 no milestone or royalty payments were made.

The Company is a party to various agreements under which it licenses technology on an exclusive basis in the field of oncology therapeutics. These agreements include License fees, Royalties and Milestone payments. The Company also has a legacy license agreement in the field of oncology diagnostics under which royalty payments are due. These royalty payments are calculated as a percent of revenue. For the three months ended March 31, 2023 and 2022, payments have not been material.

Litigation

Cardiff Oncology does not believe that it has legal liabilities that are probable or reasonably possible that require either accrual or disclosure. From time to time, the Company may become involved in various lawsuits and legal proceedings that arise in the ordinary course of business. Litigation is subject to inherent uncertainties, and an adverse result in matters may arise

from time to time that may harm the Company’s business. As of the date of this report, management believes that there are no claims against the Company, which it believes will result in a material adverse effect on the Company’s business or financial condition.

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Summary of Significant Accounting Policies (Policies)

3 Months Ended

Mar. 31, 2023

Accounting Policies [Abstract]

Net Loss Per Share

Net Loss Per Share

Basic and diluted net loss per common share is determined by dividing net loss applicable to common stockholders by the weighted-average common shares outstanding during the period. Preferred dividends are included in net loss attributable to common stockholders in the computation of basic and diluted earnings per share.

Recently Adopted Accounting Pronouncement and Recent Accounting Pronouncement Not Yet Adopted

Recent Accounting Pronouncement Not Yet Adopted

In August 2020, the FASB issued ASU No. 2020-06 ("ASU 2020-06"), Debt - Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging - Contracts in Entity’s Own Equity (Subtopic 815-40) (“ASU 2020-06”). ASU 2020-06 eliminates the beneficial conversion and cash conversion accounting models for convertible instruments. It also amends the accounting for certain contracts in an entity’s own equity that are currently accounted for as derivatives because of specific settlement provisions. In addition, ASU 2020-06 modifies how particular convertible instruments and certain contracts that may be settled in cash or shares impact the diluted EPS computation. The amendments in this update are effective for public business entities for fiscal years beginning after December 15, 2021 (or December 15, 2023, for companies who meet the SEC definition of Smaller Reporting Companies), and interim periods within those fiscal years. The amendment is to be adopted through either a fully retrospective or modified retrospective method of transition. Early adoption is permitted. The Company is currently evaluating the impact of this standard on its financial statements and related disclosures, and will adopt this standard on January 1, 2024.

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Summary of Significant Accounting Policies (Tables)

3 Months Ended

Mar. 31, 2023

Accounting Policies [Abstract]

Schedule of Antidilutive Securities Excluded from the Calculation of Diluted Net Loss per Share

The following table sets forth the outstanding potentially dilutive securities that have been excluded in the calculation of diluted net loss per share because their effect was anti-dilutive:

	March 31,
	2023	2022
Options to purchase Common Stock	6,396,895	5,467,611
Warrants to purchase Common Stock	4,296,472	4,490,159
Series A Convertible Preferred Stock	877	877
Series E Convertible Preferred Stock	—	1,342,250
	10,694,244	11,300,897

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Fair Value Measurements (Tables)

3 Months Ended

Mar. 31, 2023

Fair Value Disclosures [Abstract]

Schedule of the Company’s Assets and Liabilities that are Measured and Recognized at Fair Value on a Recurring Basis Classified Under the Appropriate Level of the Fair Value Hierarchy

The following table presents the Company’s assets and liabilities that are measured and recognized at fair value on a recurring basis classified under the appropriate level of the fair value hierarchy as of March 31, 2023, and December 31, 2022:

	Fair Value Measurements at March 31, 2023
(in thousands)	Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Assets:
Money market fund	$	14,158	$	—	$	—	$	14,158
Total included in cash and cash equivalents	14,158		—		—		14,158
Available for sale investments:
Certificate of deposit	—		13,925		—		13,925
Corporate debt securities	—		32,828		—		32,828
Commercial paper	—		10,398		—		10,398
U.S. government agencies	—		7,842				7,842
U.S. treasury securities	16,958		—		—		16,958
Total available for sale investments (1)	16,958		64,993		—		81,951
Total assets measured at fair value on a recurring basis	$	31,116	$	64,993	$	—	$	96,109

	Fair Value Measurements at December 31, 2022
(in thousands)	Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Assets:
Money market fund	$	15,722	$	—	$	—	$	15,722
Total included in cash and cash equivalents	15,722		—		—		15,722
Available for sale investments:
Certificate of deposit	—		16,023		—		16,023
Corporate debt securities	—		49,535		—		49,535
Commercial paper	—		13,187		—		13,187
U.S. government agencies	—		2,288		—		2,288
U.S. treasury securities	7,887		—		—		7,887
Total available for sale investments (1)	7,887		81,033		—		88,920
Total assets measured at fair value on a recurring basis	$	23,609	$	81,033	$	—	$	104,642

(1) Included in short-term investments in the accompanying balance sheets.

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Supplementary Balance Sheet Information (Tables)

3 Months Ended

Mar. 31, 2023

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Schedule of Investments Available-for-sale

Investments available for sale consist of the following:

	As of March 31, 2023
(in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Market Value
Maturity less than 1 year:
Certificate of deposit	$	13,964	$	1	$	(40)	$	13,925
Corporate debt securities	22,258		4		(118)		22,144
Commercial paper	10,402		3		(7)		10,398
U.S. government agencies	4,049		4		—		4,053
Total maturity less than 1 year	50,673		12		(165)		50,520
Maturity 1 to 2 years:
Corporate debt securities	10,687		24		(27)		10,684
U.S. government agencies	3,781		8		—		3,789
U.S. treasury securities	16,886		72		—		16,958
Total maturity 1 to 2 years	31,354		104		(27)		31,431
Total short-term investments	$	82,027	$	116	$	(192)	$	81,951

	As of December 31, 2022
(in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Market Value
Maturity less than 1 year:
Certificate of deposit	$	16,101	$	3	$	(81)	$	16,023
Corporate debt securities	44,806		8		(275)		44,539
Commercial paper	13,203		4		(20)		13,187
Non U.S. government	2,284		4		—		2,288
U.S. treasury securities	7,905		—		(18)		7,887
Total maturity less than 1 year	84,299		19		(394)		83,924
Maturity 1 to 2 years:
Corporate debt securities	5,016		1		(21)		4,996
Total maturity 1 to 2 years	5,016		1		(21)		4,996
Total short-term investments	$	89,315	$	20	$	(415)	$	88,920

Investments Available-for-sale in a Continuous Unrealized Loss Position

Investments available for sale that have been in a continuous unrealized loss position for greater than one-year consist of the following:

	As of March 31, 2023
(in thousands)	Fair Market Value		Gross Unrealized Loss
Corporate debt securities	$	8,151	$	(58)

Schedule of Components of Property and Equipment

Property and equipment consist of the following:

 

(in thousands)	As of March 31, 2023		As of December 31, 2022
Furniture and office equipment	$	1,066	$	1,066
Leasehold improvements	2,560		2,560
Laboratory equipment	1,153		1,056
	4,779		4,682
Less—accumulated depreciation and amortization	(3,459)		(3,413)
Property and equipment, net	$	1,320	$	1,269

Schedule of Accrued Liabilities

Accrued liabilities consisted of the following:

(in thousands)	As of March 31, 2023		As of December 31, 2022
Accrued compensation	$	983	$	1,849
Clinical trials	2,709		2,333
Research agreements and services	571		509
Director fees	125		125
Patent, license and other fees	59		24
Other accrued liabilities	108		337
Total accrued liabilities	$	4,555	$	5,177

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Leases (Tables)

3 Months Ended

Mar. 31, 2023

Leases [Abstract]

Summary of Lease Expense and Supplemental Cash Flow Information

The components of lease expense were as follows:

	Three Months Ended March 31,
(in thousands)	2023		2022
Operating lease cost	$	183	$	191
Net operating lease cost	$	183	$	191

Supplemental cash flow and other information related to leases was as follows:

	Three Months Ended March 31,
(in thousands)	2023		2022
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$	185	$	70

Supplemental Balance Sheet Information

Supplemental balance sheet information related to leases was as follows:

(in thousands)	As of March 31, 2023			As of December 31, 2022
Operating lease ROU assets	$	2,115		$	2,251
Current operating lease liabilities	$	679		$	675
Non-current operating lease liabilities	1,898			2,040
Total operating lease liabilities	$	2,577		$	2,715
Weighted-average remaining lease term–operating leases	3.9 years			4.2 years
Weighted-average discount rate–operating leases	7.0		%	7.0		%

Summary of Future Minimum Lease Payments

Total remaining annual commitments under non-cancelable lease agreements for each of the years ended December 31 are as follows:

(in thousands)
Year Ending December 31,	Operating Leases
2023 (excluding the three months ended March 31, 2023)	$	491
2024	754
2025	775
2026	796
Thereafter	136
Total future minimum lease payments	2,952
Less imputed interest	(375)
Total	$	2,577

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Stockholders' Equity (Tables)

3 Months Ended

Mar. 31, 2023

Stockholders' Equity Note [Abstract]

Schedule of Stock-Based Compensation Expense

Stock-based compensation expense related to Cardiff Oncology equity awards have been recognized in operating results as follows:

	Three Months Ended March 31,
(in thousands)	2023		2022
Included in research and development expense	$	394	$	335
Included in selling, general and administrative expense	670		817
Total stock-based compensation expense	$	1,064	$	1,152

Schedule of Assumptions to Estimate Fair Value of Stock Option Awards

The estimated fair value of stock option awards was determined on the date of grant using the Black-Scholes option valuation model with the following weighted-average assumptions during the following periods indicated:

	Three Months Ended March 31,
	2023		2022
Risk-free interest rate	3.58	%	1.84	%
Dividend yield	0	%	0	%
Expected volatility of Cardiff Oncology common stock	110	%	106	%
Expected term(1)	5.3 years		6.0 years

Summary of Stock Option Activity and of Changes in Stock Options Outstanding

A summary of stock option activity and changes in stock options outstanding is presented below:

	Total Options	Weighted-Average Exercise Price Per Share		Intrinsic Value
Balance outstanding, December 31, 2022	5,069,458	$	5.92	$	19,322
Granted	1,806,008	$	1.73
Canceled / Forfeited	(1,725)	$	7.98
Expired	(476,846)	$	6.93
Balance outstanding, March 31, 2023	6,396,895	$	4.66	$	34,107
Exercisable at March 31, 2023	2,427,304	$	6.57	$	20,517
Vested and expected to vest at March 31, 2023	6,187,656	$	4.73	$	33,160

Summary of Warrant Activity and Changes in Warrants Outstanding

A summary of warrant activity and changes in warrants outstanding, including both liability and equity classifications is presented below:

	Total Warrants	Weighted-Average Exercise Price Per Share		Weighted-Average Remaining Contractual Term
Balance outstanding, December 31, 2022	4,360,968	$	5.33	2.1 years
Expired	(64,496)	$	101.52
Balance outstanding, March 31, 2023	4,296,472	$	3.89	1.8 years

Schedule of Preferred Stock

A summary of our Company's classes of preferred stock is presented below:

				Shares outstanding
Class	Par value		Shares designated	As of March 31, 2023	As of December 31, 2022
Series A Convertible Preferred Stock	$	0.001	277,100	60,600	60,600
Series B Convertible Preferred Stock	$	0.001	8,860	—	—
Series C Convertible Preferred Stock	$	0.001	200,000	—	—
Series D Convertible Preferred Stock	$	0.0001	154,670	—	—
Series E Convertible Preferred Stock	$	0.001	865,824	—	—

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Organization and Basis of Presentation (Details) $ in Millions	Mar. 31, 2023 USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Cash, cash equivalents and short-term investments	$ 97.0

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Summary of Significant Accounting Policies - Antidilutive Securities (Details) - shares	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Net Loss Per Share
Antidilutive securities excluded from the calculation of basic and diluted loss per share (in shares)	10,694,244	11,300,897
Options to purchase Common Stock
Net Loss Per Share
Antidilutive securities excluded from the calculation of basic and diluted loss per share (in shares)	6,396,895	5,467,611
Warrants to purchase Common Stock
Net Loss Per Share
Antidilutive securities excluded from the calculation of basic and diluted loss per share (in shares)	4,296,472	4,490,159
Series A Convertible Preferred Stock
Net Loss Per Share
Antidilutive securities excluded from the calculation of basic and diluted loss per share (in shares)	877	877
Series E Convertible Preferred Stock
Net Loss Per Share
Antidilutive securities excluded from the calculation of basic and diluted loss per share (in shares)	0	1,342,250

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Fair Value Measurements - Fair Value of Assets and Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Assets:
Total available for sale investments	$ 81,951	$ 88,920
Recurring basis
Assets:
Total included in cash and cash equivalents	14,158	15,722
Total available for sale investments	81,951	88,920
Total assets measured at fair value on a recurring basis	96,109	104,642
Recurring basis | Certificate of deposit
Assets:
Total available for sale investments	13,925	16,023
Recurring basis | Corporate debt securities
Assets:
Total available for sale investments	32,828	49,535
Recurring basis | Commercial paper
Assets:
Total available for sale investments	10,398	13,187
Recurring basis | Non U.S. government
Assets:
Total available for sale investments	7,842	2,288
Recurring basis | U.S. treasury securities
Assets:
Total available for sale investments	16,958	7,887
Recurring basis | Money market fund
Assets:
Total included in cash and cash equivalents	14,158	15,722
Recurring basis | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1)
Assets:
Total included in cash and cash equivalents	14,158	15,722
Total available for sale investments	16,958	7,887
Total assets measured at fair value on a recurring basis	31,116	23,609
Recurring basis | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) | Certificate of deposit
Assets:
Total available for sale investments	0	0
Recurring basis | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) | Corporate debt securities
Assets:
Total available for sale investments	0	0
Recurring basis | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) | Commercial paper
Assets:
Total available for sale investments	0	0
Recurring basis | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) | Non U.S. government
Assets:
Total available for sale investments	0	0
Recurring basis | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) | U.S. treasury securities
Assets:
Total available for sale investments	16,958	7,887
Recurring basis | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) | Money market fund
Assets:
Total included in cash and cash equivalents	14,158	15,722
Recurring basis | Significant Other Observable Inputs (Level 2)
Assets:
Total included in cash and cash equivalents	0	0
Total available for sale investments	64,993	81,033
Total assets measured at fair value on a recurring basis	64,993	81,033
Recurring basis | Significant Other Observable Inputs (Level 2) | Certificate of deposit
Assets:
Total available for sale investments	13,925	16,023
Recurring basis | Significant Other Observable Inputs (Level 2) | Corporate debt securities
Assets:
Total available for sale investments	32,828	49,535
Recurring basis | Significant Other Observable Inputs (Level 2) | Commercial paper
Assets:
Total available for sale investments	10,398	13,187
Recurring basis | Significant Other Observable Inputs (Level 2) | Non U.S. government
Assets:
Total available for sale investments	7,842	2,288
Recurring basis | Significant Other Observable Inputs (Level 2) | U.S. treasury securities
Assets:
Total available for sale investments	0	0
Recurring basis | Significant Other Observable Inputs (Level 2) | Money market fund
Assets:
Total included in cash and cash equivalents	0	0
Recurring basis | Significant Unobservable Inputs (Level 3)
Assets:
Total included in cash and cash equivalents	0	0
Total available for sale investments	0	0
Total assets measured at fair value on a recurring basis	0	0
Recurring basis | Significant Unobservable Inputs (Level 3) | Certificate of deposit
Assets:
Total available for sale investments	0	0
Recurring basis | Significant Unobservable Inputs (Level 3) | Corporate debt securities
Assets:
Total available for sale investments	0	0
Recurring basis | Significant Unobservable Inputs (Level 3) | Commercial paper
Assets:
Total available for sale investments	0	0
Recurring basis | Significant Unobservable Inputs (Level 3) | Non U.S. government
Assets:
Total available for sale investments		0
Recurring basis | Significant Unobservable Inputs (Level 3) | U.S. treasury securities
Assets:
Total available for sale investments	0	0
Recurring basis | Significant Unobservable Inputs (Level 3) | Money market fund
Assets:
Total included in cash and cash equivalents	$ 0	$ 0

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Supplementary Balance Sheet Information - Investments Available-for-sale (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Maturity less than 1 year:
Amortized Cost	$ 50,673	$ 84,299
Gross Unrealized Gains	12	19
Gross Unrealized Losses	(165)	(394)
Fair Market Value	50,520	83,924
Maturity 1 to 2 years:
Amortized Cost	31,354	5,016
Gross Unrealized Gains	104	1
Gross Unrealized Losses	(27)	(21)
Fair Market Value	31,431	4,996
Amortized Cost	82,027	89,315
Gross Unrealized Gains	116	20
Gross Unrealized Losses	(192)	(415)
Fair Market Value	81,951	88,920
Certificate of deposit
Maturity less than 1 year:
Amortized Cost	13,964	16,101
Gross Unrealized Gains	1	3
Gross Unrealized Losses	(40)	(81)
Fair Market Value	13,925	16,023
Corporate debt securities
Maturity less than 1 year:
Amortized Cost	22,258	44,806
Gross Unrealized Gains	4	8
Gross Unrealized Losses	(118)	(275)
Fair Market Value	22,144	44,539
Maturity 1 to 2 years:
Amortized Cost	10,687	5,016
Gross Unrealized Gains	24	1
Gross Unrealized Losses	(27)	(21)
Fair Market Value	10,684	4,996
Commercial paper
Maturity less than 1 year:
Amortized Cost	10,402	13,203
Gross Unrealized Gains	3	4
Gross Unrealized Losses	(7)	(20)
Fair Market Value	10,398	13,187
U.S. government agencies
Maturity less than 1 year:
Amortized Cost	4,049
Gross Unrealized Gains	4
Gross Unrealized Losses	0
Fair Market Value	4,053
Maturity 1 to 2 years:
Amortized Cost	3,781
Gross Unrealized Gains	8
Gross Unrealized Losses	0
Fair Market Value	3,789
Non U.S. government
Maturity less than 1 year:
Amortized Cost		2,284
Gross Unrealized Gains		4
Gross Unrealized Losses		0
Fair Market Value		2,288
U.S. treasury securities
Maturity less than 1 year:
Amortized Cost		7,905
Gross Unrealized Gains		0
Gross Unrealized Losses		(18)
Fair Market Value		$ 7,887
Maturity 1 to 2 years:
Amortized Cost	16,886
Gross Unrealized Gains	72
Gross Unrealized Losses	0
Fair Market Value	$ 16,958

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Supplementary Balance Sheet Information - Investments Available-for-sale in a Continuous Loss Position (Details) - Corporate debt securities $ in Thousands	Mar. 31, 2023 USD ($)
Debt Securities, Available-for-sale [Line Items]
Fair Market Value	$ 8,151
Gross Unrealized Loss	$ (58)

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Supplementary Balance Sheet Information - Property and Equipment (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Property, equipment and depreciation and amortization
Property and equipment, gross	$ 4,779	$ 4,682
Less—accumulated depreciation and amortization	(3,459)	(3,413)
Property and equipment, net	1,320	1,269
Furniture and office equipment
Property, equipment and depreciation and amortization
Property and equipment, gross	1,066	1,066
Leasehold improvements
Property, equipment and depreciation and amortization
Property and equipment, gross	2,560	2,560
Laboratory equipment
Property, equipment and depreciation and amortization
Property and equipment, gross	$ 1,153	$ 1,056

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Supplementary Balance Sheet Information - Accrued Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accrued compensation	$ 983	$ 1,849
Clinical trials	2,709	2,333
Research agreements and services	571	509
Director fees	125	125
Patent, license and other fees	59	24
Other accrued liabilities	108	337
Total accrued liabilities	$ 4,555	$ 5,177

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Leases - Narrative (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2023 USD ($)
Leases [Abstract]
Monthly rent payments	$ 61
Annual rent increase, percentage	3.00%

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Leases - Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Leases [Abstract]
Operating lease cost	$ 183	$ 191
Net operating lease cost	$ 183	$ 191

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Leases - Supplemental Balance Sheet Information (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Leases [Abstract]
Operating lease ROU assets	$ 2,115	$ 2,251
Current operating lease liabilities	679	675
Non-current operating lease liabilities	1,898	2,040
Total operating lease liabilities	$ 2,577	$ 2,715
Weighted-average remaining lease term–operating leases	3 years 10 months 24 days	4 years 2 months 12 days
Weighted-average discount rate–operating leases	7.00%	7.00%

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Leases - Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Leases [Abstract]
Operating cash flows from operating leases	$ 185	$ 70

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Leases - Future Minimum Lease Payments (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Operating Leases
2023 (excluding the three months ended March 31, 2023)	$ 491
2024	754
2025	775
2026	796
Thereafter	136
Total future minimum lease payments	2,952
Less imputed interest	(375)
Total	$ 2,577	$ 2,715

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Stockholders' Equity - Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Stock-based compensation expense
Total stock based compensation expense	$ 1,064	$ 1,152
Options vested, fair value	1,900	1
Research and Development Expense
Stock-based compensation expense
Total stock based compensation expense	394	335
Selling, general and administrative expense
Stock-based compensation expense
Total stock based compensation expense	670	$ 817
Options to purchase Common Stock
Stock-based compensation expense
Unrecognized compensation cost	$ 10,100
Weighted-average remaining vesting period for recognition	2 years 8 months 12 days
Options outstanding, weighted average contractual life	8 years 6 months

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Stockholders' Equity - Stock Option Activity (Details) - USD ($)	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022	Dec. 31, 2022	Jun. 09, 2022
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures
Authorized shares under the plan (in shares)		3,150,000		5,150,000
Options to purchase Common Stock
Weighted-average assumptions
Risk-free interest rate	3.58%	1.84%
Dividend yield (as a percent)	0.00%	0.00%
Expected volatility (as a percent)	110.00%	106.00%
Expected term(1)	5 years 3 months 18 days	6 years
Number of Options
Balance outstanding at the beginning of the period (in shares)	5,069,458
Granted (in shares)	1,806,008
Cancelled / Forfeited (in shares)	(1,725)
Expired (in shares)	(476,846)
Balance outstanding at the end of the period (in shares)	6,396,895
Exercisable at the end of the period (in shares)	2,427,304
Vested and expected to vest (in shares)	6,187,656
Weighted Average Exercise Price Per Share
Balance outstanding at the beginning of the period (in USD per share)	$ 5.92
Granted (in USD per share)	1.73
Canceled / Forfeited (in USD per share)	7.98
Expired (in USD per share)	6.93
Balance outstanding at the end of the period (in USD per share)	4.66
Exercisable at the end of the period (in USD per share)	6.57
Vested and expected to vest (in USD per share)	$ 4.73
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures
Options outstanding, intrinsic value	$ 34,107		$ 19,322
Exercisable at the end of the period, intrinsic value	20,517
Vested and expected to vest, intrinsic value	$ 33,160
Inducement Grant Stock Options
Number of Options
Granted (in shares)	1,345,208
Equity Incentive Plan 2021
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures
Number of remaining shares available for issuance (in shares)	2,180,898

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Stockholders' Equity - Warrants (Details) - $ / shares	3 Months Ended	12 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Number of Warrants
Balance of warrants outstanding at the end of the period (in shares)	4,296,472	4,360,968
Expired (in shares)	(64,496)
Balance of warrants outstanding at the beginning of the period (in shares)	4,360,968
Weighted Average Exercise Price Per Share
Weighted average exercise price of warrants at the beginning of the period (in USD per share)	$ 5.33
Expired (in USD per share)	101.52
Weighted average exercise price of warrants at the end of the period (in USD per share)	$ 3.89	$ 5.33
Term
Weighted-Average Remaining Contractual Term	1 year 9 months 18 days	2 years 1 month 6 days

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Stockholders' Equity - Preferred Stock (Details) - USD ($) $ / shares in Units, $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Class of Stock [Line Items]
Shares designated (in shares)	20,000,000	20,000,000
Liquidation preference	$ 1,050	$ 1,044
Series A Convertible Preferred Stock
Class of Stock [Line Items]
Par value (in dollars per share)	$ 0.001
Shares designated (in shares)	277,100
Shares outstanding (in shares)	60,600	60,600
Series B Convertible Preferred Stock
Class of Stock [Line Items]
Par value (in dollars per share)	$ 0.001
Shares designated (in shares)	8,860
Shares outstanding (in shares)	0	0
Series C Convertible Preferred Stock
Class of Stock [Line Items]
Par value (in dollars per share)	$ 0.001
Shares designated (in shares)	200,000
Shares outstanding (in shares)	0	0
Series D Convertible Preferred Stock
Class of Stock [Line Items]
Par value (in dollars per share)	$ 0.0001
Shares designated (in shares)	154,670
Shares outstanding (in shares)	0	0
Series E Convertible Preferred Stock
Class of Stock [Line Items]
Par value (in dollars per share)	$ 0.001
Shares designated (in shares)	865,824
Shares outstanding (in shares)	0	0

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Commitments and Contingencies (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Milestone and royalty payments made	$ 0	$ 0