Cardiff Oncology (CRDF) 10-Q 8 Aug 24 2024 Q2 Quarterly report Financial data

Cover Page

Cover Page - shares	6 Months Ended
	Jun. 30, 2024	Aug. 06, 2024
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 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		46,549,634
Entity Central Index Key	0001213037
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q2

CONDENSED BALANCE SHEETS

CONDENSED BALANCE SHEETS - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 25,501	$ 21,655
Short-term investments	34,818	53,168
Accounts receivable and unbilled receivable	451	288
Prepaid expenses and other current assets	1,476	2,301
Total current assets	62,246	77,412
Property and equipment, net	1,095	1,238
Operating lease right-of-use assets	1,439	1,708
Other assets	1,271	1,279
Total Assets	66,051	81,637
Current liabilities:
Accounts payable	5,108	1,966
Accrued liabilities	6,712	7,783
Operating lease liabilities	702	691
Total current liabilities	12,522	10,440
Operating lease liabilities, net of current portion	1,141	1,458
Total Liabilities	13,663	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 June 30, 2024 and December 31, 2023 with liquidation preference of $1,080 and $1,068 at June 30, 2024 and December 31, 2023, respectively	0	0
Common stock, $0.0001 par value, 150,000 shares authorized; 45,602 and $44,677 shares issued and outstanding at June 30, 2024 and December 31, 2023, respectively	5	4
Additional paid-in capital	413,017	409,343
Accumulated other comprehensive loss	(97)	(67)
Accumulated deficit	(360,537)	(339,541)
Total stockholders’ equity	52,388	69,739
Total liabilities and stockholders’ equity	$ 66,051	$ 81,637

CONDENSED BALANCE SHEETS (Paren

CONDENSED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Preferred stock, shares authorized (in shares)	20,000,000	20,000,000
Temporary equity, shares authorized (in shares)	277,000	277,000
Temporary equity, shares outstanding (in shares)	61,000	61,000
Preferred stock, liquidation preference, value	$ 1,080	$ 1,068
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)	45,602,000	44,677,000
Common stock, shares outstanding (in shares)	45,602,000	44,677,000

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Income Statement [Abstract]
Royalties	$ 163	$ 108	$ 368	$ 191
Costs and expenses:
Research and development	9,493	8,020	17,501	17,072
Selling, general and administrative	3,215	4,296	6,345	7,379
Total operating expenses	12,708	12,316	23,846	24,451
Loss from operations	(12,545)	(12,208)	(23,478)	(24,260)
Interest income, net	805	1,053	1,731	1,993
Other income (expense), net	(38)	5	(42)	(106)
Total other income (expense), net	767	1,058	1,689	1,887
Net loss	(11,778)	(11,150)	(21,789)	(22,373)
Preferred stock dividend payable on Series A Convertible Preferred Stock	(6)	(6)	(12)	(12)
Net loss attributable to common stockholders	$ (11,784)	$ (11,156)	$ (21,801)	$ (22,385)
Net loss per common share - basic (in dollars per share)	$ (0.26)	$ (0.25)	$ (0.49)	$ (0.50)
Net loss per common share - diluted (in dollars per share)	$ (0.26)	$ (0.25)	$ (0.49)	$ (0.50)
Weighted-average shares outstanding - basic (in shares)	44,825	44,677	44,752	44,677
Weighted-average shares outstanding - diluted (in shares)	44,825	44,677	44,752	44,677

CONDENSED STATEMENTS OF COMPREH

CONDENSED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Statement of Comprehensive Income [Abstract]
Net loss	$ (11,778)	$ (11,150)	$ (21,789)	$ (22,373)
Other comprehensive loss:
Unrealized gain (loss) on securities available-for-sale	35	(355)	(30)	(36)
Total comprehensive loss	(11,743)	(11,505)	(21,819)	(22,409)
Preferred stock dividend payable on Series A Convertible Preferred Stock	(6)	(6)	(12)	(12)
Comprehensive loss attributable to common stockholders	$ (11,749)	$ (11,511)	$ (21,831)	$ (22,421)

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			$ 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)
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]
Net loss		(22,373)
Balance, ending (in shares) at Jun. 30, 2023					61	44,677
Balance, ending at Jun. 30, 2023		86,579			$ 0	$ 4	407,479			(431)	(320,473)
Balance, beginning (in shares) at Mar. 31, 2023					61	44,677
Balance, beginning at Mar. 31, 2023		96,503			$ 0	$ 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			$ 0	$ 4	407,479			(431)	(320,473)
Balance, beginning (in shares) at Dec. 31, 2023					61	44,677
Balance, beginning at Dec. 31, 2023		69,739	$ 0		$ 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			$ 0	$ 4	409,781			(132)	(348,759)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Accounting Standards Update [Extensible Enumeration]		Accounting Standards Update 2020-06 [Member]
Balance, beginning (in shares) at Dec. 31, 2023					61	44,677
Balance, beginning at Dec. 31, 2023		$ 69,739	$ 0		$ 0	$ 4	409,343	$ (793)		(67)	(339,541)	$ 793
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss		(21,789)
Balance, ending (in shares) at Jun. 30, 2024					61	45,602
Balance, ending at Jun. 30, 2024		52,388			$ 0	$ 5	413,017			(97)	(360,537)
Balance, beginning (in shares) at Mar. 31, 2024					61	44,710
Balance, beginning at Mar. 31, 2024		60,894			$ 0	$ 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			$ 0	$ 5	$ 413,017			$ (97)	$ (360,537)
[1] See Note 2. (2) Net of expenses of $197,000. Net of expenses of $197,000.

CONDENSED STATEMENT OF STOCKH_2

CONDENSED STATEMENT OF STOCKHOLDERS' EQUITY (Parenthetical) - USD ($)	3 Months Ended	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2024	Jun. 30, 2023
Statement of Stockholders' Equity [Abstract]
Stock issuance expenses	$ 197,000	$ 197,000	$ 0

CONDENSED STATEMENTS OF CASH FL

CONDENSED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Operating activities
Net loss	$ (21,789)	$ (22,373)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	207	188
Stock-based compensation expense	2,303	2,645
Accretion of discounts on short-term investments, net	(283)	(405)
Changes in operating assets and liabilities:
Other assets	8	(3)
Accounts receivable and unbilled receivable	(163)	610
Prepaid expenses and other current assets	696	2,260
Operating lease right-of-use assets	269	273
Accounts payable and accrued liabilities	2,088	1,293
Operating lease liabilities	(306)	(279)
Net cash used in operating activities	(16,970)	(15,791)
Investing activities:
Capital expenditures	(80)	(259)
Maturities of short-term investments	12,505	68,265
Purchases of short-term investments	(919)	(50,868)
Sales of short-term investments	7,145	1,675
Net cash provided by investing activities	18,651	18,813
Financing activities:
Proceeds from sales of common stock, net of expenses of $197 and $0, respectively	1,805	0
Proceeds from exercise of options	360	0
Net cash provided by financing activities	2,165	0
Net change in cash and cash equivalents	3,846	3,022
Cash and cash equivalents—Beginning of period	21,655	16,347
Cash and cash equivalents—End of period	25,501	19,369
Supplemental disclosure of non-cash investing and financing activities:
Acquisition of property and equipment included in accounts payable and accrued expenses	$ 0	$ 16

CONDENSED STATEMENTS OF CASH _2

CONDENSED STATEMENTS OF CASH FLOWS (Parenthetical) - USD ($)	3 Months Ended	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2024	Jun. 30, 2023
Statement of Cash Flows [Abstract]
Stock issuance expenses	$ 197,000	$ 197,000	$ 0

Organization and Basis of Prese

Organization and Basis of Presentation	6 Months Ended
	Jun. 30, 2024
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 ("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 June 30, 2024, the Company had $60.3 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.

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2024
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies During the six months ended June 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: June 30, 2024 2023 Options to purchase Common Stock 8,351,122 6,603,661 Warrants to purchase Common Stock 2,807,353 2,807,948 Series A Convertible Preferred Stock 877 877 11,159,352 9,412,486 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	6 Months Ended
	Jun. 30, 2024
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 June 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 $ 24,349 $ — $ — $ 24,349 Total included in cash and cash equivalents 24,349 — — 24,349 Available for sale investments: Certificate of deposit — 5,946 — 5,946 Corporate debt securities — 13,849 — 13,849 Commercial paper — 2,399 — 2,399 U.S. treasury securities 12,624 — — 12,624 Total available for sale investments 12,624 22,194 — 34,818 Total assets measured at fair value on a recurring basis $ 36,973 $ 22,194 $ — $ 59,167 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 Inf

Supplementary Balance Sheet Information	6 Months Ended
	Jun. 30, 2024
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Supplementary Balance Sheet Information	Supplementary Balance Sheet Information Investments available for sale Investments available for sale consisted of the following: As of June 30, 2024 (in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Market Value Maturity less than 1 year: Certificate of deposit $ 5,943 $ 3 $ — $ 5,946 Corporate debt securities 12,175 7 (28) 12,154 Commercial paper 2,399 — — 2,399 U.S. treasury securities 12,707 — (83) 12,624 Total maturity less than 1 year 33,224 10 (111) 33,123 Maturity 1 to 2 years: Corporate debt securities 1,690 5 — 1,695 U.S. treasury securities — — — — Total maturity 1 to 2 years 1,690 5 — 1,695 Total short-term investments $ 34,914 $ 15 $ (111) $ 34,818 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 U.S. treasury securities — — — — 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 June 30, 2024, 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 consisted of the following: As of June 30, 2024 (in thousands) Fair Market Value Gross Unrealized Loss Corporate debt securities $ 4,333 $ (19) U.S. treasury securities 9,794 (72) Total $ 14,127 $ (91) 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 June 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 (3,954) (3,752) Property and equipment, net $ 1,095 $ 1,238 Accrued Liabilities Accrued liabilities consisted of the following: (in thousands) As of June 30, As of December 31, Clinical trials $ 3,832 $ 4,309 Accrued compensation 1,790 2,737 Research agreements and services 867 530 Other accrued liabilities 223 207 Total accrued liabilities $ 6,712 $ 7,783

Stockholders' Equity

Stockholders' Equity	6 Months Ended
	Jun. 30, 2024
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 June 30, Six Months Ended June 30, (in thousands) 2024 2023 2024 2023 Included in research and development expense $ 397 $ 297 $ 786 $ 691 Included in selling, general and administrative expense 782 1,284 1,517 1,954 Total stock-based compensation expense $ 1,179 $ 1,581 $ 2,303 $ 2,645 The unrecognized compensation cost related to non-vested stock options outstanding at June 30, 2024, net of estimated forfeitures, was $9.4 million, which is expected to be recognized over a weighted-average remaining vesting period of 2.5 years. The weighted-average remaining contractual term of outstanding options as of June 30, 2024, was approximately 8.0 years. The total fair value of stock options vested during the six months ended June 30, 2024 and 2023, were $2.7 million and $3.2 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: Six Months Ended June 30, 2024 2023 Risk-free interest rate 4.06 % 3.61 % 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 (65,314) $ 13.96 Balance outstanding, June 30, 2024 8,351,122 $ 4.02 $ 1,169,885 Exercisable at June 30, 2024 4,124,114 $ 4.85 $ 468,750 Vested and expected to vest at June 30, 2024 8,121,830 $ 4.05 $ 1,118,569 2021 Equity Incentive Plan In June 2021 the Company's stockholders approved the 2021 Omnibus Equity Incentive Plan ("2021 Plan"). As of June 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 June 30, 2024, there were 3,153,005 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 June 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, June 30, 2024 2,807,353 $ 2.40 1.4 years Sale of Common Stock During June 2024, the Company received net proceeds of $1.8 million from the sale of 0.8 million shares of its common stock under the Sales Agreement with Jefferies LLC.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2024
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 six months ended June 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. 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. For the six months ended June 30, 2024 and 2023, payments have not been material. Litigation As previously disclosed in the Supplement to the Company’s Proxy Statement for its Annual Meeting held on June 20, 2024 (the “2024 Annual Meeting”) as filed with the SEC on June 3, 2024, a purported stockholder of the Company filed a class action and derivative complaint in the Court of Chancery of the State of Delaware against the Company, and against James Armitage, Mark Erlander, Rodney Markin, Mani Mohindru, Gary Pace, Renee Tannenbaum, Lale White, Tod Smeal, Fairooz Kabbinavar and James Levine. The complaint alleges, among other things, that the By-Laws of the Company (the “By-Laws”), in effect as of May 13, 2024, require directors to be elected, and other business to be transacted, using a voting standard that treats broker non-votes as votes “against” these actions. This purported stockholder also claims that directors Renee Tannenbaum and Mani Mohindru were not validly elected in 2022 and 2023, respectively, and that the Company did not validly amend its 2021 Equity Incentive Plan at the annual meeting of stockholders held in 2022, in each case because the voting standard urged by the purported stockholder was not satisfied. The Board of Directors adopted amendments to the By-Laws to confirm and clarify the applicable voting standards that applied to the business transacted at the 2024 Annual Meeting. The Board of Directors also adopted resolutions to rescind equity grants that were made in reliance on the 2022 amendment to the 2021 Equity Incentive Plan and approved replacement grants with terms identical to the equity grants rescinded. The replacement grants were approved by the stockholders at the 2024 Annual Meeting. On June 26, 2024, the plaintiff dismissed the complaint with prejudice as to the plaintiff, with the court retaining jurisdiction to determine plaintiff’s counsel’s application for an award of attorneys’ fees. Currently, the fees cannot be estimated, and no fees have been accrued. The Company does not believe these fees will be material. 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	6 Months Ended
	Jun. 30, 2024
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events Sale of Common Stock From July 1, 2024 through August 6, 2024, the Company sold 0.9 million shares of its common stock under the Sales Agreement with Jefferies LLC. Gross proceeds from these sales was $2.3 million.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2024
Accounting Policies [Abstract]
Net Loss Per Share	Net Loss 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)	6 Months Ended
	Jun. 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: June 30, 2024 2023 Options to purchase Common Stock 8,351,122 6,603,661 Warrants to purchase Common Stock 2,807,353 2,807,948 Series A Convertible Preferred Stock 877 877 11,159,352 9,412,486

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 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 June 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 $ 24,349 $ — $ — $ 24,349 Total included in cash and cash equivalents 24,349 — — 24,349 Available for sale investments: Certificate of deposit — 5,946 — 5,946 Corporate debt securities — 13,849 — 13,849 Commercial paper — 2,399 — 2,399 U.S. treasury securities 12,624 — — 12,624 Total available for sale investments 12,624 22,194 — 34,818 Total assets measured at fair value on a recurring basis $ 36,973 $ 22,194 $ — $ 59,167 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)	6 Months Ended
	Jun. 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 June 30, 2024 (in thousands) Amortized Cost Gross Unrealized Gains Gross Unrealized Losses Fair Market Value Maturity less than 1 year: Certificate of deposit $ 5,943 $ 3 $ — $ 5,946 Corporate debt securities 12,175 7 (28) 12,154 Commercial paper 2,399 — — 2,399 U.S. treasury securities 12,707 — (83) 12,624 Total maturity less than 1 year 33,224 10 (111) 33,123 Maturity 1 to 2 years: Corporate debt securities 1,690 5 — 1,695 U.S. treasury securities — — — — Total maturity 1 to 2 years 1,690 5 — 1,695 Total short-term investments $ 34,914 $ 15 $ (111) $ 34,818 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 U.S. treasury securities — — — — 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 June 30, 2024 (in thousands) Fair Market Value Gross Unrealized Loss Corporate debt securities $ 4,333 $ (19) U.S. treasury securities 9,794 (72) Total $ 14,127 $ (91) 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 June 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 (3,954) (3,752) Property and equipment, net $ 1,095 $ 1,238
Schedule of Accrued Liabilities	Accrued liabilities consisted of the following: (in thousands) As of June 30, As of December 31, Clinical trials $ 3,832 $ 4,309 Accrued compensation 1,790 2,737 Research agreements and services 867 530 Other accrued liabilities 223 207 Total accrued liabilities $ 6,712 $ 7,783

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	6 Months Ended
	Jun. 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 June 30, Six Months Ended June 30, (in thousands) 2024 2023 2024 2023 Included in research and development expense $ 397 $ 297 $ 786 $ 691 Included in selling, general and administrative expense 782 1,284 1,517 1,954 Total stock-based compensation expense $ 1,179 $ 1,581 $ 2,303 $ 2,645
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: Six Months Ended June 30, 2024 2023 Risk-free interest rate 4.06 % 3.61 % 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 (65,314) $ 13.96 Balance outstanding, June 30, 2024 8,351,122 $ 4.02 $ 1,169,885 Exercisable at June 30, 2024 4,124,114 $ 4.85 $ 468,750 Vested and expected to vest at June 30, 2024 8,121,830 $ 4.05 $ 1,118,569
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, June 30, 2024 2,807,353 $ 2.40 1.4 years

Organization and Basis of Pre_2

Organization and Basis of Presentation (Details) $ in Millions	Jun. 30, 2024 USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Cash, cash equivalents and short-term investments	$ 60.3

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Antidilutive Securities (Details) - shares	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Net Loss Per Share
Antidilutive securities excluded from the calculation of basic and diluted loss per share (in shares)	11,159,352	9,412,486
Options to purchase Common Stock
Net Loss Per Share
Antidilutive securities excluded from the calculation of basic and diluted loss per share (in shares)	8,351,122	6,603,661
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)	Jan. 01, 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	Jun. 30, 2024	Dec. 31, 2023
Assets:
Total available for sale investments	$ 34,818	$ 53,168
Recurring basis
Assets:
Total included in cash and cash equivalents	24,349	21,606
Total available for sale investments	34,818	53,168
Total assets measured at fair value on a recurring basis	59,167	74,774
Recurring basis | Certificate of deposit
Assets:
Total available for sale investments	5,946	8,333
Recurring basis | Corporate debt securities
Assets:
Total available for sale investments	13,849	19,373
Recurring basis | Commercial paper
Assets:
Total available for sale investments	2,399	6,202
Recurring basis | U.S. government agencies
Assets:
Total available for sale investments		834
Recurring basis | U.S. treasury securities
Assets:
Total available for sale investments	12,624	18,426
Recurring basis | Money market fund
Assets:
Total included in cash and cash equivalents	24,349	21,606
Recurring basis | Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1)
Assets:
Total included in cash and cash equivalents	24,349	21,606
Total available for sale investments	12,624	18,426
Total assets measured at fair value on a recurring basis	36,973	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 available for sale investments	12,624	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	24,349	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	22,194	34,742
Total assets measured at fair value on a recurring basis	22,194	34,742
Recurring basis | Significant Other Observable Inputs (Level 2) | Certificate of deposit
Assets:
Total available for sale investments	5,946	8,333
Recurring basis | Significant Other Observable Inputs (Level 2) | Corporate debt securities
Assets:
Total available for sale investments	13,849	19,373
Recurring basis | Significant Other Observable Inputs (Level 2) | Commercial paper
Assets:
Total available for sale investments	2,399	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 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 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	Jun. 30, 2024	Dec. 31, 2023
Maturity less than 1 year:
Amortized Cost	$ 33,224	$ 26,293
Gross Unrealized Gains	10	33
Gross Unrealized Losses	(111)	(17)
Fair Market Value	33,123	26,309
Maturity 1 to 2 years:
Amortized Cost	1,690	26,942
Gross Unrealized Gains	5	6
Gross Unrealized Losses	0	(89)
Fair Market Value	1,695	26,859
Amortized Cost	34,914	53,235
Gross Unrealized Gains	15	39
Gross Unrealized Losses	(111)	(106)
Fair Market Value	34,818	53,168
Certificate of deposit
Maturity less than 1 year:
Amortized Cost	5,943	8,317
Gross Unrealized Gains	3	16
Gross Unrealized Losses	0	0
Fair Market Value	5,946	8,333
Corporate debt securities
Maturity less than 1 year:
Amortized Cost	12,175	10,948
Gross Unrealized Gains	7	8
Gross Unrealized Losses	(28)	(16)
Fair Market Value	12,154	10,940
Maturity 1 to 2 years:
Amortized Cost	1,690	8,437
Gross Unrealized Gains	5	6
Gross Unrealized Losses	0	(10)
Fair Market Value	1,695	8,433
Commercial paper
Maturity less than 1 year:
Amortized Cost	2,399	6,193
Gross Unrealized Gains	0	9
Gross Unrealized Losses	0	0
Fair Market Value	2,399	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	12,707	0
Gross Unrealized Gains	0	0
Gross Unrealized Losses	(83)	0
Fair Market Value	12,624	0
Maturity 1 to 2 years:
Amortized Cost	0	18,505
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	(79)
Fair Market Value	$ 0	$ 18,426

Supplementary Balance Sheet I_4

Supplementary Balance Sheet Information - Investments Available-for-sale in a Continuous Loss Position (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Debt Securities, Available-for-sale [Line Items]
Fair Market Value	$ 14,127
Gross Unrealized Loss	(91)
Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Fair Market Value	4,333	$ 397
Gross Unrealized Loss	(19)	$ (3)
U.S. treasury securities
Debt Securities, Available-for-sale [Line Items]
Fair Market Value	9,794
Gross Unrealized Loss	$ (72)

Supplementary Balance Sheet I_5

Supplementary Balance Sheet Information - Property and Equipment (Details) - USD ($) $ in Thousands	Jun. 30, 2024	Dec. 31, 2023
Property, equipment and depreciation and amortization
Property and equipment, gross	$ 5,049	$ 4,990
Less—accumulated depreciation and amortization	(3,954)	(3,752)
Property and equipment, net	1,095	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	Jun. 30, 2024	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accrued compensation	$ 1,790	$ 2,737
Clinical trials	3,832	4,309
Research agreements and services	867	530
Other accrued liabilities	223	207
Total accrued liabilities	$ 6,712	$ 7,783

Stockholders' Equity - Stock-ba

Stockholders' Equity - Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Stock-based compensation expense
Total stock based compensation expense	$ 1,179	$ 1,581	$ 2,303	$ 2,645
Options vested, fair value			2,700	3,200
Research and Development Expense
Stock-based compensation expense
Total stock based compensation expense	397	297	786	691
Selling, general and administrative expense
Stock-based compensation expense
Total stock based compensation expense	782	$ 1,284	1,517	$ 1,954
Options to purchase Common Stock
Stock-based compensation expense
Unrecognized compensation cost	$ 9,400		$ 9,400
Weighted-average remaining vesting period for recognition			2 years 6 months
Options outstanding, weighted average contractual life			8 years

Stockholders' Equity - Stock Op

Stockholders' Equity - Stock Option Activity (Details) - USD ($)		3 Months Ended	6 Months Ended
	May 30, 2024	Jun. 30, 2024	Jun. 30, 2024	Jun. 30, 2023	Dec. 31, 2023
Number of Options
Granted (in shares)	1,697,712
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures
Authorized shares under the plan (in shares)		8,150,000	8,150,000
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
Options to purchase Common Stock
Weighted-average assumptions
Risk-free interest rate			4.06%	3.61%
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)			(65,314)
Balance outstanding at the end of the period (in shares)		8,351,122	8,351,122
Exercisable at the end of the period (in shares)		4,124,114	4,124,114
Vested and expected to vest (in shares)		8,121,830	8,121,830
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)			3.40
Exercised (in USD per share)			2.69
Forfeited and expired (in USD per share)			13.96
Balance outstanding at the end of the period (in USD per share)		$ 4.02	4.02
Exercisable at the end of the period (in USD per share)		4.85	4.85
Vested and expected to vest (in USD per share)		$ 4.05	$ 4.05
Share-based Compensation Arrangement by Share-based Payment Award, Options, Additional Disclosures
Options outstanding, intrinsic value		$ 1,169,885	$ 1,169,885		$ 23,926
Exercisable at the end of the period, intrinsic value		468,750	468,750
Vested and expected to vest, intrinsic value		$ 1,118,569	$ 1,118,569
Inducement Grant Stock Options
Number of Options
Granted (in shares)		1,380,248
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)		3,153,005	3,153,005

Stockholders' Equity - Warrants

Stockholders' Equity - Warrants (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Jun. 30, 2024	Jun. 30, 2023
Number of Warrants
Balance of warrants outstanding at the end of the period (in shares)	2,807,353	2,807,353		2,807,353
Expired (in shares)		(595)
Balance of warrants outstanding at the beginning of the period (in shares)			2,807,948	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	$ 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)	$ 2.40	$ 2.40		$ 2.40
Term
Weighted-Average Remaining Contractual Term			1 year 10 months 24 days	1 year 4 months 24 days
Proceeds from sale of common stock and warrants, net	$ 1,800			$ 1,805	$ 0
Sale of stock, number of shares issued (in shares)	800,000

Commitments and Contingencies (

Commitments and Contingencies (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
Milestone and royalty payments made	$ 0	$ 0

Subsequent Events (Details)

Subsequent Events (Details) - USD ($) shares in Millions, $ in Millions	1 Months Ended
	Aug. 06, 2024	Jun. 30, 2024
Subsequent Event [Line Items]
Sale of stock, number of shares issued (in shares)		0.8
Subsequent Event | Jefferies LLC Sales Agreement
Subsequent Event [Line Items]
Sale of stock, number of shares issued (in shares)	0.9
Proceeds from sale of stock	$ 2.3