Cardiff Oncology (CRDF) 10-Q 7 Nov 24 2024 Q3 Quarterly report Financial data

Cover Page

Cover Page - shares	9 Months Ended
	Sep. 30, 2024	Nov. 04, 2024
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2024
Document Transition Report	false
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
Security Exchange Name	NASDAQ
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		51,133,747
Entity Central Index Key	0001213037
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q3

CONDENSED BALANCE SHEETS

CONDENSED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 13,038	$ 21,655
Short-term investments	44,629	53,168
Accounts receivable and unbilled receivable	618	288
Prepaid expenses and other current assets	1,047	2,301
Total current assets	59,332	77,412
Property and equipment, net	993	1,238
Operating lease right-of-use assets	1,304	1,708
Other assets	1,267	1,279
Total Assets	62,896	81,637
Current liabilities:
Accounts payable	4,643	1,966
Accrued liabilities	7,175	7,783
Operating lease liabilities	707	691
Total current liabilities	12,525	10,440
Operating lease liabilities, net of current portion	979	1,458
Total Liabilities	13,504	11,898
Commitments and contingencies (Note 6)
Stockholders’ equity
Preferred stock, 20,000 shares authorized; 277 designated as Series A Convertible Preferred Stock; 61 shares outstanding at September 30, 2024 and December 31, 2023 with liquidation preference of $1,086 and $1,068 at September 30, 2024 and December 31, 2023 respectively	0	0
Common stock, $0.0001 par value, 150,000 shares authorized; 48,731 and 44,677 shares issued and outstanding at September 30, 2024 and December 31, 2023 respectively	5	4
Additional paid-in capital	421,697	409,343
Accumulated other comprehensive gain (loss)	82	(67)
Accumulated deficit	(372,392)	(339,541)
Total stockholders’ equity	49,392	69,739
Total liabilities and stockholders’ equity	$ 62,896	$ 81,637

CONDENSED BALANCE SHEETS (Paren

CONDENSED BALANCE SHEETS (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Preferred stock, shares authorized (in shares)	20,000	20,000
Temporary equity, shares authorized (in shares)	277	277
Temporary equity, shares outstanding (in shares)	61	61
Preferred stock, liquidation preference, value	$ 1,086	$ 1,068
Common stock, par value (in USD per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	150,000	150,000
Common stock, shares issued (in shares)	48,731	44,677
Common stock, shares outstanding (in shares)	48,731	44,677

CONDENSED STATEMENTS OF OPERATI

CONDENSED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Income Statement [Abstract]
Royalty revenues	$ 165	$ 141	$ 532	$ 332
Costs and expenses:
Research and development	9,640	8,022	27,140	25,094
Selling, general and administrative	3,126	2,939	9,471	10,318
Total operating expenses	12,766	10,961	36,611	35,412
Loss from operations	(12,601)	(10,820)	(36,079)	(35,080)
Other income (expense), net:
Interest income, net	741	1,068	2,472	3,061
Other income (expense), net	5	21	(37)	(85)
Total other income, net	746	1,089	2,435	2,976
Net loss	(11,855)	(9,731)	(33,644)	(32,104)
Preferred stock dividend payable on Series A Convertible Preferred Stock	(6)	(6)	(18)	(18)
Net loss attributable to common stockholders	$ (11,861)	$ (9,737)	$ (33,662)	$ (32,122)
Net loss per common share - basic	$ (0.25)	$ (0.22)	$ (0.74)	$ (0.72)
Net loss per common share - diluted	$ (0.25)	$ (0.22)	$ (0.74)	$ (0.72)
Weighted-average shares outstanding - basic	46,865	44,677	45,461	44,677
Weighted-average shares outstanding - diluted	46,865	44,677	45,461	44,677

CONDENSED STATEMENTS OF COMPREH

CONDENSED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Statement of Comprehensive Income [Abstract]
Net loss	$ (11,855)	$ (9,731)	$ (33,644)	$ (32,104)
Other comprehensive loss:
Unrealized gain (loss) on securities available-for-sale	179	24	149	(12)
Total comprehensive loss	(11,676)	(9,707)	(33,495)	(32,116)
Preferred stock dividend payable on Series A Convertible Preferred Stock	(6)	(6)	(18)	(18)
Comprehensive loss attributable to common stockholders	$ (11,682)	$ (9,713)	$ (33,513)	$ (32,134)

CONDENSED STATEMENT OF STOCKHOL

CONDENSED STATEMENT OF STOCKHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands		Total	Cumulative Effect, Period of Adoption, Adjustment	[1]	Preferred Stock	Common Stock	Additional Paid-In Capital	Additional Paid-In Capital Cumulative Effect, Period of Adoption, Adjustment	[1]	Accumulated Other Comprehensive Loss	Accumulated Deficit	Accumulated Deficit Cumulative Effect, Period of Adoption, Adjustment	[1]
Balance, beginning (in shares) at Dec. 31, 2022					61	44,677
Balance, beginning at Dec. 31, 2022		$ 106,343				$ 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				$ 4	405,898			(76)	(309,323)
Balance, beginning (in shares) at Dec. 31, 2022					61	44,677
Balance, beginning at Dec. 31, 2022		106,343				$ 4	404,834			(395)	(298,100)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss		(32,104)
Balance, ending (in shares) at Sep. 30, 2023					61	44,677
Balance, ending at Sep. 30, 2023		77,827				$ 4	408,434			(407)	(330,204)
Balance, beginning (in shares) at Mar. 31, 2023					61	44,677
Balance, beginning at Mar. 31, 2023		96,503				$ 4	405,898			(76)	(309,323)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation		1,581					1,581
Other comprehensive gain (loss)		(355)								(355)
Net loss		(11,150)									(11,150)
Balance, ending (in shares) at Jun. 30, 2023					61	44,677
Balance, ending at Jun. 30, 2023		86,579				$ 4	407,479			(431)	(320,473)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation		955					955
Other comprehensive gain (loss)		24								24
Net loss		(9,731)									(9,731)
Balance, ending (in shares) at Sep. 30, 2023					61	44,677
Balance, ending at Sep. 30, 2023		77,827				$ 4	408,434			(407)	(330,204)
Balance, beginning (in shares) at Dec. 31, 2023					61	44,677
Balance, beginning at Dec. 31, 2023		69,739	$ 0			$ 4	409,343	$ (793)		(67)	(339,541)	$ 793
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation		1,124					1,124
Issuance of common stock upon exercise of stock options (in shares)						33
Issuance of common stock upon exercise of stock options		107					107
Other comprehensive gain (loss)		(65)								(65)
Net loss		(10,011)									(10,011)
Balance, ending (in shares) at Mar. 31, 2024					61	44,710
Balance, ending at Mar. 31, 2024		$ 60,894				$ 4	409,781			(132)	(348,759)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accounting Standards Update [Extensible Enumeration]		us-gaap:AccountingStandardsUpdate202006Member
Balance, beginning (in shares) at Dec. 31, 2023					61	44,677
Balance, beginning at Dec. 31, 2023		$ 69,739	$ 0			$ 4	409,343	$ (793)		(67)	(339,541)	$ 793
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss		(33,644)
Balance, ending (in shares) at Sep. 30, 2024					61	48,731
Balance, ending at Sep. 30, 2024		49,392				$ 5	421,697			82	(372,392)
Balance, beginning (in shares) at Mar. 31, 2024					61	44,710
Balance, beginning at Mar. 31, 2024		60,894				$ 4	409,781			(132)	(348,759)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock, net of expenses (in shares)	[2]					792
Issuance of common stock, net of expenses	[2]	1,805				$ 1	1,804
Stock-based compensation		1,179					1,179
Issuance of common stock upon exercise of stock options (in shares)						100
Issuance of common stock upon exercise of stock options		253					253
Other comprehensive gain (loss)		35								35
Net loss		(11,778)									(11,778)
Balance, ending (in shares) at Jun. 30, 2024					61	45,602
Balance, ending at Jun. 30, 2024		52,388				$ 5	413,017			(97)	(360,537)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock, net of expenses (in shares)	[3]					3,129
Issuance of common stock, net of expenses	[3]	7,427					7,427
Stock-based compensation		1,253					1,253
Other comprehensive gain (loss)		179								179
Net loss		(11,855)									(11,855)
Balance, ending (in shares) at Sep. 30, 2024					61	48,731
Balance, ending at Sep. 30, 2024		$ 49,392				$ 5	$ 421,697			$ 82	$ (372,392)
[1] See Note 2. Net of expenses of $ 197,000 . Net of expenses of $ 285,000 .

CONDENSED STATEMENT OF STOCKH_2

CONDENSED STATEMENT OF STOCKHOLDERS' EQUITY (Parenthetical) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Sep. 30, 2024	Sep. 30, 2023
Statement of Stockholders' Equity [Abstract]
Stock issuance expenses	$ 285,000	$ 197,000	$ 482,000	$ 0

CONDENSED STATEMENTS OF CASH FL

CONDENSED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Operating activities
Net loss	$ (33,644)	$ (32,104)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	308	295
Stock-based compensation expense	3,556	3,600
Accretion of discounts on short-term investments, net	(440)	(716)
Changes in operating assets and liabilities:
Accounts receivable and unbilled receivable	(330)	573
Prepaid expenses and other current assets	1,084	3,188
Operating lease right-of-use assets	404	408
Other assets	12
Accounts payable and accrued liabilities	2,087	1,428
Operating lease liabilities	(463)	(420)
Net cash used in operating activities	(27,426)	(23,748)
Investing activities:
Capital expenditures	(80)	(574)
Maturities of short-term investments	22,595	80,534
Purchases of short-term investments	(23,563)	(67,491)
Sales of short-term investments	10,265	10,165
Net cash provided by investing activities	9,217	22,634
Financing activities:
Proceeds from sales of common stock, net of expenses of $680 and $0, respectively	9,232
Proceeds from exercise of options	360
Net cash provided by financing activities	9,592
Net change in cash and cash equivalents	(8,617)	(1,114)
Cash and cash equivalents—Beginning of period	21,655	16,347
Cash and cash equivalents—End of period	$ 13,038	$ 15,233

CONDENSED STATEMENTS OF CASH _2

CONDENSED STATEMENTS OF CASH FLOWS (Parenthetical) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Sep. 30, 2024	Sep. 30, 2023
Statement of Cash Flows [Abstract]
Stock issuance expenses	$ 285,000	$ 197,000	$ 482,000	$ 0

Pay vs Performance Disclosure

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2024	Sep. 30, 2023
Pay vs Performance Disclosure
Net Income (Loss)	$ (11,855)	$ (11,778)	$ (10,011)	$ (9,731)	$ (11,150)	$ (11,223)	$ (33,644)	$ (32,104)

Insider Trading Arrangements

Insider Trading Arrangements	3 Months Ended
	Sep. 30, 2024
Trading Arrangements, by Individual
Rule 10b5-1 Arrangement Adopted	false
Non-Rule 10b5-1 Arrangement Adopted	false
Rule 10b5-1 Arrangement Terminated	false
Non-Rule 10b5-1 Arrangement Terminated	false

Organization and Basis of Prese

Organization and Basis of Presentation	9 Months Ended
	Sep. 30, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Basis of Presentation	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 ("SoC") therapeutics in clinical programs targeting indications such as RAS-mutated metastatic colorectal cancer (“mCRC”), as well as ongoing or planned investigator-initiated trials in metastatic pancreatic ductal adenocarcinoma (“mPDAC”), small cell lung cancer (“SCLC”), and triple negative breast cancer (“TNBC”). 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 SoC 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, 2023, 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, 2023, included in the Company’s annual report on Form 10-K filed with the SEC on February 29, 2024. Liquidity The Company has incurred net losses since its inception and has negative operating cash flows. As of September 30, 2024, the Company had $ 57.7 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.

Summary of Significant Accounti

Summary of Significant Accounting Policies	9 Months Ended
	Sep. 30, 2024
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	2. Summary of Significant Accounting Policies During the nine months ended September 30, 2024, 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, 2023. 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: September 30, 2024 2023 Options to purchase Common Stock 8,348,344 6,652,427 Warrants to purchase Common Stock 2,807,353 2,807,948 Series A Convertible Preferred Stock 877 877 11,156,574 9,461,252 Recently Adopted Accounting Pronouncement 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. This update was effective for the Company on January 1, 2024. The amendment is to be adopted through either a fully retrospective or modified retrospective method of transition. Early adoption is permitted. The Company adopted this standard as of January 1, 2024 using the modified-retrospective method. As a result of the adoption the Company reversed the accretion of preferred stock dividends originally recorded in 2005 related to the Series A Convertible Preferred Stock of $ 793,000 .

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2024
Fair Value Disclosures [Abstract]
Fair Value Measurements	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 September 30, 2024, and December 31, 2023: Fair Value Measurements at (in thousands) Quoted Prices in Active Markets for Identical Assets and Liabilities Significant Other Observable Inputs Significant Unobservable Inputs Total Assets: Money market fund $ 12,591 $ — $ — $ 12,591 U.S. treasury securities 298 — — 298 Total included in cash and cash equivalents 12,889 — — 12,889 Available for sale investments: Certificate of deposit — 334 — 334 Corporate debt securities — 25,091 — 25,091 Commercial paper — 310 — 310 U.S. treasury securities 18,894 — — 18,894 Total available for sale investments 18,894 25,735 — 44,629 Total assets measured at fair value on a recurring basis $ 31,783 $ 25,735 $ — $ 57,518 Fair Value Measurements at (in thousands) Quoted Prices in Active Markets for Identical Assets and Liabilities Significant Other Observable Inputs Significant Unobservable Inputs Total Assets: Money market fund $ 21,606 $ — $ — $ 21,606 Total included in cash and cash equivalents 21,606 — — 21,606 Available for sale investments: Certificate of deposit — 8,333 — 8,333 Corporate debt securities — 19,373 — 19,373 Commercial paper — 6,202 — 6,202 U.S. government agencies — 834 — 834 U.S. treasury securities 18,426 — — 18,426 Total available for sale investments 18,426 34,742 — 53,168 Total assets measured at fair value on a recurring basis $ 40,032 $ 34,742 $ — $ 74,774 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 nine months ended September 30, 2024 .

Supplementary Balance Sheet Inf

Supplementary Balance Sheet Information	9 Months Ended
	Sep. 30, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Supplementary Balance Sheet Information	4. Supplementary Balance Sheet Information Investments available for sale Investments available for sale consisted of the following: As of September 30, 2024 (in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Market Value Maturity less than 1 year: Certificate of deposit $ 334 $ — $ — $ 334 Corporate debt securities 16,213 36 ( 2 ) 16,247 Commercial paper 308 2 — 310 U.S. treasury securities 18,896 8 ( 10 ) 18,894 Total maturity less than 1 year 35,751 46 ( 12 ) 35,785 Maturity 1 to 2 years: Corporate debt securities 8,796 49 ( 1 ) 8,844 Total maturity 1 to 2 years 8,796 49 ( 1 ) 8,844 Total short-term investments $ 44,547 $ 95 $ ( 13 ) $ 44,629 As of December 31, 2023 (in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Market Value Maturity less than 1 year: Certificate of deposit $ 8,317 $ 16 $ — $ 8,333 Corporate debt securities 10,948 8 ( 16 ) 10,940 Commercial paper 6,193 9 — 6,202 U.S. government agencies 835 — ( 1 ) 834 Total maturity less than 1 year 26,293 33 ( 17 ) 26,309 Maturity 1 to 2 years: Corporate debt securities 8,437 6 ( 10 ) 8,433 U.S. treasury securities 18,505 — ( 79 ) 18,426 Total maturity 1 to 2 years 26,942 6 ( 89 ) 26,859 Total short-term investments $ 53,235 $ 39 $ ( 106 ) $ 53,168 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 September 30, 2024, were substantially due to changes 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 consisted of the following: As of September 30, 2024 (in thousands) Fair Market Value Gross Unrealized Loss Total $ — $ — As of December 31, 2023 (in thousands) Fair Market Value Gross Unrealized Loss Corporate debt securities $ 397 $ ( 3 ) Property and equipment Property and equipment consisted of the following: (in thousands) As of September 30, As of December 31, Furniture and office equipment $ 1,067 $ 1,067 Leasehold improvements 2,568 2,568 Laboratory equipment 1,414 1,355 Property and equipment, gross 5,049 4,990 Less—accumulated depreciation and amortization ( 4,056 ) ( 3,752 ) Property and equipment, net $ 993 $ 1,238 Accrued Liabilities Accrued liabilities consisted of the following: (in thousands) As of September 30, As of December 31, Clinical trials $ 4,271 $ 4,309 Accrued compensation 1,993 2,737 Research agreements and services 637 530 Other accrued liabilities 274 207 Total accrued liabilities $ 7,175 $ 7,783

Stockholders' Equity

Stockholders' Equity	9 Months Ended
	Sep. 30, 2024
Stockholders' Equity Note [Abstract]
Stockholders' Equity	5. 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 September 30, Nine Months Ended September 30, (in thousands) 2024 2023 2024 2023 Included in research and development expense $ 436 $ 294 $ 1,223 $ 985 Included in selling, general and administrative expense 817 661 2,333 2,615 Total stock-based compensation expense $ 1,253 $ 955 $ 3,556 $ 3,600 The unrecognized compensation cost related to non-vested stock options outstanding at September 30, 2024, net of estimated forfeitures, was $ 8.1 million, which is expected to be recognized over a weighted-average remaining vesting period of 2.4 years. The weighted-average remaining contractual term of outstanding options as of September 30, 2024, was approximately 7.7 years. The total fair value of stock options vested during the nine months ended September 30, 2024 and 2023, were $ 3.6 million and $ 4.0 million, 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: Nine Months Ended September 30, 2024 2023 Risk-free interest rate 4.06 % 3.62 % Dividend yield 0 % 0 % Expected volatility of Cardiff Oncology common stock 106 % 109 % Expected term 5.8 years 5.3 years A summary of stock option activity and changes in stock options outstanding is presented below: Total Options Weighted-Average Intrinsic Balance outstanding, December 31, 2023 6,650,954 $ 4.27 $ 23,926 Granted 1,899,096 $ 3.40 Exercised ( 133,614 ) $ 2.69 Forfeited and expired ( 68,092 ) $ 23.06 Balance outstanding, September 30, 2024 8,348,344 $ 3.94 $ 2,542,885 Exercisable at September 30, 2024 4,431,853 $ 4.64 $ 1,235,936 Vested and expected to vest at September 30, 2024 8,132,900 $ 3.97 $ 2,451,731 2021 Equity Incentive Plan In June 2021 the Company's stockholders approved the 2021 Omnibus Equity Incentive Plan ("2021 Plan"). As of September 30, 2024 the number of authorized shares in the 2021 Plan is equal to the sum of (i) 8,150,000 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. As of September 30, 2024 , there were 3,155,783 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 September 30, 2024, an aggregate of 1,380,248 shares were issuable upon the exercise of inducement grant stock options approved by the Company. Rescinding and reissuance of March 2024 stock options On May 30, 2024, the Board of Directors of the Company approved the rescinding of an aggregate of 1,697,712 shares of common stock issuable upon exercise of stock options granted on March 7, 2024 at an exercise price of $ 3.51 per share to employees and officers of the Company. On May 30, 2024, the Board of Directors of the Company approved the grant of an aggregate of 1,697,712 shares of common stock issuable upon exercise of stock options at an exercise price of $ 3.51 per share to employees and officers of the Company, subject to stockholder approval of an increase in the shares of common stock available for issuance pursuant to the Company’s 2021 Equity Incentive Plan at the Company’s annual meeting on June 20, 2024. The increase of shares available was approved by shareholders at the June 20, 2024 meeting, thus completing the requirements for the reissuance of the grant. The terms of the reissued grant were identical to the rescinded grant, therefore the transaction does not represent a stock option modification. Warrants A summary of warrant activity and changes in warrants outstanding, classified as equity is presented below: Total Warrants Weighted-Average Weighted-Average Balance outstanding, December 31, 2023 2,807,948 $ 2.45 1.9 years Expired ( 595 ) $ 252.72 Balance outstanding, September 30, 2024 2,807,353 $ 2.40 1.2 years Sale of Common Stock During the three months ended September 30, 2024 , the Company received net proceeds of $ 7.4 million from the sale of 3.1 million shares of its common stock under the Sales Agreement with Jefferies LLC. During the nine months ended September 30, 2024 , the Company received net proceeds of $ 9.2 million from the sale of 3.9 million shares of its common stock under the Sales Agreement with Jefferies LLC.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2024
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	6. 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 nine months ended September 30, 2024 and 2023 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. For the nine months ended September 30, 2024 and 2023, payments have not been material. The Company also has a legacy license agreement in the field of oncology diagnostics under which royalty payments are due to the Company. These royalty payments are calculated as a percent of revenue. Litigation On May 13, 2024, a purported stockholder of the Company filed a putative class action in the Court of Chancery of the State of Delaware captioned Vrana v. James O. Armitage et al. , C.A. No. 2024-0507-MTZ (Del. Ch.) (“Action”). The Action was mooted on June 20, 2024 when the Company’s stockholders voted: (i) to elect all 7 nominees for director to serve until the 2025 Annual Meeting of Stockholders; and (ii) to approve an amendment to the Company’s 2021 Equity Incentive Plan to increase the number of shares issuable thereunder to 8,150,000 shares. On June 26, 2024, the Court entered an order dismissing the Action but retained jurisdiction solely for the purpose of resolving the plaintiff’s counsel’s anticipated motion for an award of attorneys’ fees and expenses. Without admitting any fault or wrongdoing, the Company agreed to pay $ 400,000 in attorneys’ fees and expenses to the plaintiff’s counsel in connection with the mooted claims. In entering the order, the Court did not review, and did not pass judgment on, the payment of the attorneys’ fees and expenses. The Company paid the plaintiff’s counsel fees and expenses during September 2024, which was recorded within selling general and administrative expense. 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 could result in a material adverse effect on the Company’s business or financial condition.

Subsequent Events

Subsequent Events	9 Months Ended
	Sep. 30, 2024
Subsequent Events [Abstract]
Subsequent Events	7. Subsequent Events Sale of Common Stock From October 1, 2024 through November 4, 2024, the Company sold 2.4 million shares of its common stock under the Sales Agreement with Jefferies LLC. Gross proceeds from these sales was $ 7.0 million .

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2024
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	Recently Adopted Accounting Pronouncement 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. This update was effective for the Company on January 1, 2024. The amendment is to be adopted through either a fully retrospective or modified retrospective method of transition. Early adoption is permitted. The Company adopted this standard as of January 1, 2024 using the modified-retrospective method. As a result of the adoption the Company reversed the accretion of preferred stock dividends originally recorded in 2005 related to the Series A Convertible Preferred Stock of $ 793,000 .

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	9 Months Ended
	Sep. 30, 2024
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: September 30, 2024 2023 Options to purchase Common Stock 8,348,344 6,652,427 Warrants to purchase Common Stock 2,807,353 2,807,948 Series A Convertible Preferred Stock 877 877 11,156,574 9,461,252

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2024
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 September 30, 2024, and December 31, 2023: Fair Value Measurements at (in thousands) Quoted Prices in Active Markets for Identical Assets and Liabilities Significant Other Observable Inputs Significant Unobservable Inputs Total Assets: Money market fund $ 12,591 $ — $ — $ 12,591 U.S. treasury securities 298 — — 298 Total included in cash and cash equivalents 12,889 — — 12,889 Available for sale investments: Certificate of deposit — 334 — 334 Corporate debt securities — 25,091 — 25,091 Commercial paper — 310 — 310 U.S. treasury securities 18,894 — — 18,894 Total available for sale investments 18,894 25,735 — 44,629 Total assets measured at fair value on a recurring basis $ 31,783 $ 25,735 $ — $ 57,518 Fair Value Measurements at (in thousands) Quoted Prices in Active Markets for Identical Assets and Liabilities Significant Other Observable Inputs Significant Unobservable Inputs Total Assets: Money market fund $ 21,606 $ — $ — $ 21,606 Total included in cash and cash equivalents 21,606 — — 21,606 Available for sale investments: Certificate of deposit — 8,333 — 8,333 Corporate debt securities — 19,373 — 19,373 Commercial paper — 6,202 — 6,202 U.S. government agencies — 834 — 834 U.S. treasury securities 18,426 — — 18,426 Total available for sale investments 18,426 34,742 — 53,168 Total assets measured at fair value on a recurring basis $ 40,032 $ 34,742 $ — $ 74,774

Supplementary Balance Sheet I_2

Supplementary Balance Sheet Information (Tables)	9 Months Ended
	Sep. 30, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Investments Available-for-sale	Investments available for sale consisted of the following: As of September 30, 2024 (in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Market Value Maturity less than 1 year: Certificate of deposit $ 334 $ — $ — $ 334 Corporate debt securities 16,213 36 ( 2 ) 16,247 Commercial paper 308 2 — 310 U.S. treasury securities 18,896 8 ( 10 ) 18,894 Total maturity less than 1 year 35,751 46 ( 12 ) 35,785 Maturity 1 to 2 years: Corporate debt securities 8,796 49 ( 1 ) 8,844 Total maturity 1 to 2 years 8,796 49 ( 1 ) 8,844 Total short-term investments $ 44,547 $ 95 $ ( 13 ) $ 44,629 As of December 31, 2023 (in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Market Value Maturity less than 1 year: Certificate of deposit $ 8,317 $ 16 $ — $ 8,333 Corporate debt securities 10,948 8 ( 16 ) 10,940 Commercial paper 6,193 9 — 6,202 U.S. government agencies 835 — ( 1 ) 834 Total maturity less than 1 year 26,293 33 ( 17 ) 26,309 Maturity 1 to 2 years: Corporate debt securities 8,437 6 ( 10 ) 8,433 U.S. treasury securities 18,505 — ( 79 ) 18,426 Total maturity 1 to 2 years 26,942 6 ( 89 ) 26,859 Total short-term investments $ 53,235 $ 39 $ ( 106 ) $ 53,168
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 consisted of the following: As of September 30, 2024 (in thousands) Fair Market Value Gross Unrealized Loss Total $ — $ — As of December 31, 2023 (in thousands) Fair Market Value Gross Unrealized Loss Corporate debt securities $ 397 $ ( 3 )
Schedule of Components of Property and Equipment	Property and equipment consisted of the following: (in thousands) As of September 30, As of December 31, Furniture and office equipment $ 1,067 $ 1,067 Leasehold improvements 2,568 2,568 Laboratory equipment 1,414 1,355 Property and equipment, gross 5,049 4,990 Less—accumulated depreciation and amortization ( 4,056 ) ( 3,752 ) Property and equipment, net $ 993 $ 1,238
Schedule of Accrued Liabilities	Accrued liabilities consisted of the following: (in thousands) As of September 30, As of December 31, Clinical trials $ 4,271 $ 4,309 Accrued compensation 1,993 2,737 Research agreements and services 637 530 Other accrued liabilities 274 207 Total accrued liabilities $ 7,175 $ 7,783

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	9 Months Ended
	Sep. 30, 2024
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 September 30, Nine Months Ended September 30, (in thousands) 2024 2023 2024 2023 Included in research and development expense $ 436 $ 294 $ 1,223 $ 985 Included in selling, general and administrative expense 817 661 2,333 2,615 Total stock-based compensation expense $ 1,253 $ 955 $ 3,556 $ 3,600
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: Nine Months Ended September 30, 2024 2023 Risk-free interest rate 4.06 % 3.62 % Dividend yield 0 % 0 % Expected volatility of Cardiff Oncology common stock 106 % 109 % Expected term 5.8 years 5.3 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 Intrinsic Balance outstanding, December 31, 2023 6,650,954 $ 4.27 $ 23,926 Granted 1,899,096 $ 3.40 Exercised ( 133,614 ) $ 2.69 Forfeited and expired ( 68,092 ) $ 23.06 Balance outstanding, September 30, 2024 8,348,344 $ 3.94 $ 2,542,885 Exercisable at September 30, 2024 4,431,853 $ 4.64 $ 1,235,936 Vested and expected to vest at September 30, 2024 8,132,900 $ 3.97 $ 2,451,731
Summary of Warrant Activity and Changes in Warrants Outstanding	A summary of warrant activity and changes in warrants outstanding, classified as equity is presented below: Total Warrants Weighted-Average Weighted-Average Balance outstanding, December 31, 2023 2,807,948 $ 2.45 1.9 years Expired ( 595 ) $ 252.72 Balance outstanding, September 30, 2024 2,807,353 $ 2.40 1.2 years

Organization and Basis of Pre_2

Organization and Basis of Presentation - Narrative (Details) $ in Millions	Sep. 30, 2024 USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Cash, cash equivalents and short-term investments	$ 57.7

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Antidilutive Securities (Details) - shares	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Net Loss Per Share
Antidilutive securities excluded from the calculation of basic and diluted loss per share (in shares)	11,156,574	9,461,252
Options to purchase Common Stock
Net Loss Per Share
Antidilutive securities excluded from the calculation of basic and diluted loss per share (in shares)	8,348,344	6,652,427
Warrants to purchase Common Stock
Net Loss Per Share
Antidilutive securities excluded from the calculation of basic and diluted loss per share (in shares)	2,807,353	2,807,948
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

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Narrative (Details)	1 Months Ended
	Aug. 06, 2024 USD ($)
Cumulative Effect, Period of Adoption, Adjustment | Series A Convertible Preferred Stock
Conversion of Stock [Line Items]
Temporary equity, dividends, adjustment	$ 793,000

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value of Assets and Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Assets:
Total available for sale investments	$ 44,629	$ 53,168
Recurring basis
Assets:
Total included in cash and cash equivalents	12,889	21,606
Total available for sale investments	44,629	53,168
Total assets measured at fair value on a recurring basis	57,518	74,774
Recurring basis | Certificate of deposit
Assets:
Total available for sale investments	334	8,333
Recurring basis | Corporate debt securities
Assets:
Total available for sale investments	25,091	19,373
Recurring basis | Commercial paper
Assets:
Total available for sale investments	310	6,202
Recurring basis | U.S. government agencies
Assets:
Total available for sale investments		834
Recurring basis | U.S. treasury securities
Assets:
Total included in cash and cash equivalents	298
Total available for sale investments	18,894	18,426
Recurring basis | Money market fund
Assets:
Total included in cash and cash equivalents	12,591	21,606
Recurring basis | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1)
Assets:
Total included in cash and cash equivalents	12,889	21,606
Total available for sale investments	18,894	18,426
Total assets measured at fair value on a recurring basis	31,783	40,032
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) | U.S. government agencies
Assets:
Total available for sale investments		0
Recurring basis | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) | U.S. treasury securities
Assets:
Total included in cash and cash equivalents	298
Total available for sale investments	18,894	18,426
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	12,591	21,606
Recurring basis | Significant Other Observable Inputs (Level 2)
Assets:
Total included in cash and cash equivalents	0	0
Total available for sale investments	25,735	34,742
Total assets measured at fair value on a recurring basis	25,735	34,742
Recurring basis | Significant Other Observable Inputs (Level 2) | Certificate of deposit
Assets:
Total available for sale investments	334	8,333
Recurring basis | Significant Other Observable Inputs (Level 2) | Corporate debt securities
Assets:
Total available for sale investments	25,091	19,373
Recurring basis | Significant Other Observable Inputs (Level 2) | Commercial paper
Assets:
Total available for sale investments	310	6,202
Recurring basis | Significant Other Observable Inputs (Level 2) | U.S. government agencies
Assets:
Total available for sale investments		834
Recurring basis | Significant Other Observable Inputs (Level 2) | U.S. treasury securities
Assets:
Total included in cash and cash equivalents	0
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) | U.S. government agencies
Assets:
Total available for sale investments		0
Recurring basis | Significant Unobservable Inputs (Level 3) | U.S. treasury securities
Assets:
Total included in cash and cash equivalents	0
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

Supplementary Balance Sheet I_3

Supplementary Balance Sheet Information - Investments Available-for-sale (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Maturity less than 1 year:
Amortized Cost	$ 35,751	$ 26,293
Gross Unrealized Gains	46	33
Gross Unrealized Losses	(12)	(17)
Fair Market Value	35,785	26,309
Maturity 1 to 2 years:
Amortized Cost	8,796	26,942
Gross Unrealized Gains	49	6
Gross Unrealized Losses	(1)	(89)
Fair Market Value	8,844	26,859
Amortized Cost	44,547	53,235
Gross Unrealized Gains	95	39
Gross Unrealized Losses	(13)	(106)
Fair Market Value	44,629	53,168
Certificate of deposit
Maturity less than 1 year:
Amortized Cost	334	8,317
Gross Unrealized Gains	0	16
Gross Unrealized Losses	0	0
Fair Market Value	334	8,333
Corporate debt securities
Maturity less than 1 year:
Amortized Cost	16,213	10,948
Gross Unrealized Gains	36	8
Gross Unrealized Losses	(2)	(16)
Fair Market Value	16,247	10,940
Maturity 1 to 2 years:
Amortized Cost	8,796	8,437
Gross Unrealized Gains	49	6
Gross Unrealized Losses	(1)	(10)
Fair Market Value	8,844	8,433
Commercial paper
Maturity less than 1 year:
Amortized Cost	308	6,193
Gross Unrealized Gains	2	9
Gross Unrealized Losses	0	0
Fair Market Value	310	6,202
U.S. government agencies
Maturity less than 1 year:
Amortized Cost		835
Gross Unrealized Gains		0
Gross Unrealized Losses		(1)
Fair Market Value		834
U.S. treasury securities
Maturity less than 1 year:
Amortized Cost	18,896
Gross Unrealized Gains	8
Gross Unrealized Losses	(10)
Fair Market Value	$ 18,894
Maturity 1 to 2 years:
Amortized Cost		18,505
Gross Unrealized Gains		0
Gross Unrealized Losses		(79)
Fair Market Value		$ 18,426

Supplementary Balance Sheet I_4

Supplementary Balance Sheet Information - Investments Available-for-sale in a Continuous Loss Position (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Debt Securities, Available-for-sale [Line Items]
Fair Market Value	$ 0
Gross Unrealized Loss	$ 0
Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Fair Market Value		$ 397
Gross Unrealized Loss		$ (3)

Supplementary Balance Sheet I_5

Supplementary Balance Sheet Information - Property and Equipment (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Property, equipment and depreciation and amortization
Property and equipment, gross	$ 5,049	$ 4,990
Less—accumulated depreciation and amortization	(4,056)	(3,752)
Property and equipment, net	993	1,238
Furniture and office equipment
Property, equipment and depreciation and amortization
Property and equipment, gross	1,067	1,067
Leasehold improvements
Property, equipment and depreciation and amortization
Property and equipment, gross	2,568	2,568
Laboratory equipment
Property, equipment and depreciation and amortization
Property and equipment, gross	$ 1,414	$ 1,355

Supplementary Balance Sheet I_6

Supplementary Balance Sheet Information - Accrued Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Clinical trials	$ 4,271	$ 4,309
Accrued compensation	1,993	2,737
Research agreements and services	637	530
Other accrued liabilities	274	207
Total accrued liabilities	$ 7,175	$ 7,783

Stockholders' Equity - Stock-ba

Stockholders' Equity - Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Stock-based compensation expense
Total stock-based compensation expense	$ 1,253	$ 955	$ 3,556	$ 3,600
Research and Development Expense
Stock-based compensation expense
Total stock-based compensation expense	436	294	1,223	985
Selling, general and administrative expense
Stock-based compensation expense
Total stock-based compensation expense	$ 817	$ 661	$ 2,333	$ 2,615

Stockholders' Equity (Additiona

Stockholders' Equity (Additional Information) (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended	9 Months Ended
	May 30, 2024	Sep. 30, 2024	Sep. 30, 2024	Sep. 30, 2023	Jun. 20, 2024
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Options vested, fair value			$ 3,600	$ 4,000
Authorized shares under the plan (in shares)		8,150,000	8,150,000		8,150,000
Granted (in shares)	1,697,712
Stock repurchased and retired during period, shares (in shares)	1,697,712
Shares acquired, average cost per share (in dollars per share)	$ 3.51
Share-based compensation arrangement by share-based payment award, options, grants in period, weighted average grant date fair value (in dollars per share)	$ 3.51
Proceeds from sale of common stock and warrants, net		$ 7,400	$ 9,232
Sale of Stock, Number of Shares Issued in Transaction		3,100,000	3,900,000
Equity Incentive Plan 2021
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Number of remaining shares available for issuance (in shares)		3,155,783	3,155,783
Options to purchase Common Stock
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Unrecognized compensation cost		$ 8,100	$ 8,100
Weighted-average remaining vesting period for recognition			2 years 4 months 24 days
Options outstanding, weighted average contractual life			7 years 8 months 12 days
Granted (in shares)			1,899,096
Inducement Grant Stock Options
Share-Based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Granted (in shares)			1,380,248

Stockholders' Equity - Stock Op

Stockholders' Equity - Stock Option Activity (Details) - USD ($)		9 Months Ended
	May 30, 2024	Sep. 30, 2024	Sep. 30, 2023	Dec. 31, 2023
Number of Options
Granted (in shares)	1,697,712
Options to purchase Common Stock
Weighted-average assumptions
Risk-free interest rate		4.06%	3.62%
Dividend yield (as a percent)		0%	0%
Expected volatility (as a percent)		106%	109%
Expected term		5 years 9 months 18 days	5 years 3 months 18 days
Number of Options
Balance outstanding at the beginning of the period (in shares)		6,650,954
Granted (in shares)		1,899,096
Exercised (in shares)		(133,614)
Forfeited and expired (in shares)		(68,092)
Balance outstanding at the end of the period (in shares)		8,348,344
Exercisable at the end of the period (in shares)		4,431,853
Vested and expected to vest (in shares)		8,132,900
Weighted Average Exercise Price Per Share
Balance outstanding at the beginning of the period (in USD per share)		$ 4.27
Granted (in USD per share)		3.4
Exercised (in USD per share)		2.69
Forfeited and expired (in USD per share)		23.06
Balance outstanding at the end of the period (in USD per share)		3.94
Exercisable at the end of the period (in USD per share)		4.64
Vested and expected to vest (in USD per share)		$ 3.97
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures
Options outstanding, intrinsic value		$ 2,542,885		$ 23,926
Exercisable at the end of the period, intrinsic value		1,235,936
Vested and expected to vest, intrinsic value		$ 2,451,731
Inducement Grant Stock Options
Number of Options
Granted (in shares)		1,380,248

Stockholders' Equity - Warrants

Stockholders' Equity - Warrants (Details) - $ / shares	9 Months Ended	12 Months Ended
	Sep. 30, 2024	Dec. 31, 2023
Number of Warrants
Balance of warrants outstanding at the beginning of the period (in shares)	2,807,948
Expired (in shares)	(595)
Balance of warrants outstanding at the end of the period (in shares)	2,807,353	2,807,948
Weighted Average Exercise Price Per Share
Weighted average exercise price of warrants at the beginning of the period (in USD per share)	$ 2.45
Expired (in USD per share)	252.72
Weighted average exercise price of warrants at the end of the period (in USD per share)	$ 2.4	$ 2.45
Term
Weighted-Average Remaining Contractual Term	1 year 2 months 12 days	1 year 10 months 24 days

Commitments and Contingencies (

Commitments and Contingencies (Details) - USD ($)	1 Months Ended	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2024	Sep. 30, 2023	Jun. 20, 2024
Commitments and Contingencies Disclosure [Abstract]
Milestone and royalty payments made		$ 0	$ 0
Authorized shares under the plan	8,150,000	8,150,000		8,150,000
Payment for attorney fees and expenses	$ 400,000

Subsequent Events (Details)

Subsequent Events (Details) - USD ($) shares in Millions, $ in Millions	1 Months Ended	3 Months Ended	9 Months Ended
	Nov. 04, 2024	Sep. 30, 2024	Sep. 30, 2024
Subsequent Event [Line Items]
Sale of stock, number of shares issued (in shares)		3.1	3.9
Subsequent Event | Jefferies LLC Sales Agreement
Subsequent Event [Line Items]
Sale of stock, number of shares issued (in shares)	2.4
Proceeds from sale of stock	$ 7