0001628280-24-007948 | 10-K | XBRL Viewer

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Leases - Lease Expense (Details) - USD ($) $ in Thousands	12 Months Ended
Leases - Lease Expense (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Leases [Abstract]
Operating lease cost	$ 714	$ 754
Net operating lease cost	$ 714	$ 754

Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Income Statement [Abstract]
Royalty revenues	$ 488	$ 386
Costs and expenses:
Research and development	32,857	27,107
Selling, general and administrative	13,043	13,181
Total operating expenses	45,900	40,288
Loss from operations	(45,412)	(39,902)
Other income (expense), net:
Interest income, net	4,069	1,581
Other expense, net	(98)	(383)
Total other income, net	3,971	1,198
Net loss	(41,441)	(38,704)
Preferred stock dividend payable on Series A Convertible Preferred Stock	(24)	(24)
Net loss attributable to common stockholders	$ (41,465)	$ (38,728)
Net loss per common share - basic (in dollars per share)	$ (0.93)	$ (0.89)
Net loss per common share - diluted (in dollars per share)	$ (0.93)	$ (0.89)
Weighted-average shares outstanding - basic (in shares)	44,677	43,600
Weighted-average shares outstanding - diluted (in shares)	44,677	43,600

Stock-Based Compensation

12 Months Ended

Dec. 31, 2023

Share-Based Payment Arrangement [Abstract]

Stock-Based Compensation

2021 Equity Incentive Plan

In June 2021 the Company's stockholders approved the 2021 Omnibus Equity Incentive Plan ("2021 Plan"). The number of authorized shares in the 2021 plan is equal to the sum of (i) 3,150,000 shares, plus (ii) the number of shares of Common Stock reserved, but unissued under the 2014 Plan; and (iii) the number of shares of Common Stock underlying forfeited awards under the 2014 Plan. On June 9, 2022 the shareholders approved an increase of shares authorized in the 2021 Plan to 5,150,000. As of December 31, 2023, there were 2,013,871 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

In July 2021, the Company began issuing equity awards to certain new employees as inducement grants outside of its 2021 Plan. As of December 31, 2023, an aggregate of 1,435,256 shares were issuable upon the exercise of inducement grant stock options approved by the Company.

Modification of Stock Options

In June 2023 the Company modified stock options for a departing employee. The modification resulted in an incremental stock-based compensation expense of $0.6 million during the year ended December 31, 2023.

In June 2022 one of the Company's directors did not seek another term on the Board of Directors. At the time of departure, the Compensation Committee passed a resolution to extend the expiration date of the vested stock options, and to immediately accelerate the vesting of the unvested options. The Company recorded incremental reduction to stock compensation expense of $0.1 million during the year ended December 31, 2022, related to the modifications.

Stock-based compensation has been recognized in operating results as follows:


(in thousands)	Years ended December 31,
	2023		2022

Research and development expenses	$	1,279	$	1,035

Selling, general and administrative expenses	3,230		3,221

Total stock-based compensation	$	4,509	$	4,256

Stock Options

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 assumptions during the years indicated below:


	Years ended December 31,
	2023	2022
Risk-free interest rate (range)	3.56% - 4.06%	1.62% - 3.75%
Dividend yield	0%	0%
Expected volatility (range)	105% - 110%	98% - 110%
Expected volatility (weighted-average)	109%	106%
Expected term (in years)	5.2 years	6.0 years

Risk-free interest rate — Based on the daily yield curve rates for U.S. Treasury obligations with maturities that correspond to the expected term of the Company’s stock options.

Dividend yield — Cardiff Oncology has not paid any dividends on common stock since its inception and does not anticipate paying dividends on its common stock in the foreseeable future.

Expected volatility — Based on the historical volatility of Cardiff Oncology’s common stock.

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

Forfeitures — The Company estimates forfeitures based on its historical experience.

The weighted-average fair value per share of all options granted during the years ended December 31, 2023 and 2022, estimated as of the grant date using the Black-Scholes option valuation model, was $1.35 and $2.55 per share, respectively.

The unrecognized compensation cost related to non-vested stock options outstanding at December 31, 2023 was $6.6 million. The weighted-average remaining amortization period at December 31, 2023 for non-vested stock options was 2.1 years.

The total fair value of shares vested during the years ended December 31, 2023 and 2022 was $4.8 million and $4.7 million, respectively.

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


	Number of Options	Weighted-Average Exercise Price Per Share		Intrinsic Value		Weighted-Average Remaining Contractual Life














Balance outstanding, December 31, 2022	5,069,458	$	5.92	$	19,322	7.4 years
Granted	2,138,624	$	1.70


Forfeited and expired	(557,128)	$	9.43
Balance Outstanding, December 31, 2023	6,650,954	$	4.27	$	23,926	7.9 years
Vested and exercisable, December 31, 2023	3,124,492	$	5.66	$	22,456	6.9 years
Vested and expected to vest, December 31, 2023	6,462,464	$	4.33	$	23,853	7.8 years

Basis of Presentation and Summary of Significant Accounting Policies - Anti-dilutive Share Equivalents (Details) - shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Net Loss Per Share
Antidilutive securities excluded from computation of earnings per share (in shares)	9,459,779	9,431,303
Options to purchase Common Stock
Net Loss Per Share
Antidilutive securities excluded from computation of earnings per share (in shares)	6,650,954	5,069,458
Warrants to purchase Common Stock
Net Loss Per Share
Antidilutive securities excluded from computation of earnings per share (in shares)	2,807,948	4,360,968
Series A Convertible Preferred Stock
Net Loss Per Share
Antidilutive securities excluded from computation of earnings per share (in shares)	877	877

Stockholders' Equity - Schedule of Series A Preferred Stock (Details) - USD ($)	Dec. 31, 2023	Dec. 31, 2022
Class of Stock [Line Items]
Stated Value per share liquidation	$ 606,000	$ 606,000
Liquidation preference - Series A Convertible Preferred Stock	1,068,000	1,044,000
Series A Convertible Preferred Stock
Class of Stock [Line Items]
Cumulative unpaid preferred stock dividends	$ 462,000	$ 438,000

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

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+ Details

Fair Value Measurements (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Assets:
Total available for sale investments	$ 53,168	$ 88,920
Recurring basis
Assets:
Total included in cash and cash equivalents	21,606	15,722
Total available for sale investments	53,168	88,920
Total assets measured at fair value on a recurring basis	74,774	104,642
Recurring basis \| Certificate of deposit
Assets:
Total available for sale investments	8,333	16,023
Recurring basis \| Corporate debt securities
Assets:
Total available for sale investments	19,373	49,535
Recurring basis \| Commercial paper
Assets:
Total available for sale investments	6,202	13,187
Recurring basis \| U.S. government agencies
Assets:
Total available for sale investments	834	2,288
Recurring basis \| U.S. treasury securities
Assets:
Total available for sale investments	18,426	7,887
Recurring basis \| Money market fund
Assets:
Total included in cash and cash equivalents	21,606	15,722
Recurring basis \| Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1)
Assets:
Total included in cash and cash equivalents	21,606	15,722
Total available for sale investments	18,426	7,887
Total assets measured at fair value on a recurring basis	40,032	23,609
Recurring basis \| Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) \| Certificate of deposit
Assets:
Total available for sale investments	0	0
Recurring basis \| Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) \| Corporate debt securities
Assets:
Total available for sale investments	0	0
Recurring basis \| Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) \| Commercial paper
Assets:
Total available for sale investments	0	0
Recurring basis \| Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) \| U.S. government agencies
Assets:
Total available for sale investments	0	0
Recurring basis \| Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) \| U.S. treasury securities
Assets:
Total available for sale investments	18,426	7,887
Recurring basis \| Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1) \| Money market fund
Assets:
Total included in cash and cash equivalents	21,606	15,722
Recurring basis \| Significant Other Observable Inputs (Level 2)
Assets:
Total included in cash and cash equivalents	0	0
Total available for sale investments	34,742	81,033
Total assets measured at fair value on a recurring basis	34,742	81,033
Recurring basis \| Significant Other Observable Inputs (Level 2) \| Certificate of deposit
Assets:
Total available for sale investments	8,333	16,023
Recurring basis \| Significant Other Observable Inputs (Level 2) \| Corporate debt securities
Assets:
Total available for sale investments	19,373	49,535
Recurring basis \| Significant Other Observable Inputs (Level 2) \| Commercial paper
Assets:
Total available for sale investments	6,202	13,187
Recurring basis \| Significant Other Observable Inputs (Level 2) \| U.S. government agencies
Assets:
Total available for sale investments	834	2,288
Recurring basis \| Significant Other Observable Inputs (Level 2) \| U.S. treasury securities
Assets:
Total available for sale investments	0	0
Recurring basis \| Significant Other Observable Inputs (Level 2) \| Money market fund
Assets:
Total included in cash and cash equivalents	0	0
Recurring basis \| Significant Unobservable Inputs (Level 3)
Assets:
Total included in cash and cash equivalents	0	0
Total available for sale investments	0	0
Total assets measured at fair value on a recurring basis	0	0
Recurring basis \| Significant Unobservable Inputs (Level 3) \| Certificate of deposit
Assets:
Total available for sale investments	0	0
Recurring basis \| Significant Unobservable Inputs (Level 3) \| Corporate debt securities
Assets:
Total available for sale investments	0	0
Recurring basis \| Significant Unobservable Inputs (Level 3) \| Commercial paper
Assets:
Total available for sale investments	0	0
Recurring basis \| Significant Unobservable Inputs (Level 3) \| 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

Commitments and Contingencies - Research and Development and Clinical Trial Agreements (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Milestone or royalty payments	$ 0	$ 0

Supplementary Balance Sheet Information - Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accrued compensation	$ 2,737	$ 1,849
Clinical trials	4,309	2,333
Research agreements and services	530	509
Other accrued liabilities	207	486
Total accrued liabilities	$ 7,783	$ 5,177

Income Taxes - Significant Components of Company's Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Tax computed at the federal statutory rate	$ (8,703)	$ (8,128)
State tax, net of federal tax benefit	(645)	(518)
Permanent items	(2)	32,369
Stock based compensation	902	553
Research and development credits	(515)	(319)
Other	(126)	(1)
Valuation allowance increase (decrease)	9,089	(23,956)
Provision for income taxes	$ 0	$ 0
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Tax computed at the federal statutory rate	21.00%	21.00%
State tax, net of federal tax benefit	2.00%	1.00%
Permanent items	0.00%	(84.00%)
Stock based compensation	(2.00%)	(1.00%)
Research and development credits	1.00%	1.00%
Other	0.00%	0.00%
Valuation allowance increase (decrease)	(22.00%)	62.00%
Provision for income taxes	0.00%	0.00%

Derivative Financial Instruments - Warrants

12 Months Ended

Dec. 31, 2023

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Derivative Financial Instruments - Warrants

Derivative Financial Instruments — Warrants

Certain warrants issued in connection with the Company’s equity financings are accounted for as derivative liabilities. Accordingly, the warrants are remeasured at each balance sheet date based on their estimated fair value using the Black-Scholes option pricing model. These warrants expired during the first quarter of 2023. Changes in fair value are recorded within Company’s statements of operations.

The assumptions used to determine the fair value of the warrants using the Black-Scholes option pricing model were:


	As of December 31, 2022
Fair value of Cardiff Oncology common stock	$1.40
Expected warrant term	0.1 years
Risk-free interest rate	4.12	%
Expected volatility of Cardiff Oncology common stock	54	%
Dividend yield	0	%

Expected volatility is based on the historical volatility of Cardiff Oncology’s common stock. The warrants have a transferability provision and based on guidance for instruments issued with such a provision, Cardiff Oncology used the remaining contractual term as the expected term of the warrants. The risk-free interest rate is based on the U.S. Treasury security rates consistent with the expected remaining term of the warrants at each balance sheet date.

The following table sets forth the components of changes in the Company’s derivative financial instruments—warrants liability balance, valued using the Black-Scholes option pricing method, for the periods indicated.


(in thousands, except for number of warrants)
Date	Description	Number of Warrants	Derivative Instrument Liability
December 31, 2021	Balance of derivative financial instruments—warrants liability	64,496	$	285

	Change in fair value of derivative financial instruments—warrants during the year recognized as a gain in the statement of operations	—	(285)
December 31, 2022	Balance of derivative financial instruments—warrants liability	64,496	—
	Expiration of Derivative Financial Instruments	(64,496)	—
	Change in fair value of derivative financial instruments—warrants during the year recognized as a loss in the statement of operations	—	—
December 31, 2023	Balance of derivative financial instruments—warrants liability	—	$	—

Stockholders' Equity - Series A Convertible Preferred Stock (Details) - USD ($)		3 Months Ended	12 Months Ended
	Mar. 17, 2006	Sep. 30, 2008	Dec. 31, 2023	Dec. 31, 2022
Accumulated Deficit
Class of Stock [Line Items]
Accrued dividend during the period			$ 24,000	$ 24,000
Series A Convertible Preferred Stock
Class of Stock [Line Items]
Cumulative dividend rate (as a percent)			4.00%
Cumulative unpaid preferred stock dividends			$ 462,000	$ 438,000
Stated value (in dollars per share)			$ 10
Conversion price per share (in dollars per share)	$ 691.20	$ 928.80	691.20
Period during which the conversion price is subject to adjustment for dilutive issuances	12 months
Share price for 20 consecutive trading days for automatic conversion			$ 1,857.6
Number of consecutive trading days in which the closing price of the entity's common stock must equal or exceed a specified price in order for the preferred stock to be automatically converted			20 days
Number of common stock shares traded per day during the 20 trading days for the preferred stock to be automatically converted			116
Number of trading days in which the specified volume of common stock must be traded for the preferred stock to be automatically converted			20 days

Supplementary Balance Sheet Information (Tables)

12 Months Ended

Dec. 31, 2023

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Components of Short-term investments

Short-term investments available-for-sale securities consist of the following:


	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


	As of December 31, 2022
(in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Market Value
Maturity less than 1 year:
Certificate of deposit	$	16,101	$	3	$	(81)	$	16,023
Corporate debt securities	44,806		8		(275)		44,539
Commercial paper	13,203		4		(20)		13,187

U.S. government agencies	2,284		4		—		2,288
U.S. treasury securities	7,905		—		(18)		7,887
Total maturity less than 1 year	84,299		19		(394)		83,924
Maturity 1 to 2 years:
Corporate debt securities	5,016		1		(21)		4,996

Total maturity 1 to 2 years	5,016		1		(21)		4,996

Total short-term investments	$	89,315	$	20	$	(415)	$	88,920

Debt Securities, Available-for-Sale, Unrealized Loss Position, Fair Value

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


	As of December 31, 2023
(in thousands)	Fair Market Value		Gross Unrealized Loss

Corporate debt securities	$	397	$	(3)


Total short-term investments	$	397	$	(3)


	As of December 31, 2022
(in thousands)	Fair Market Value		Gross Unrealized Loss

Corporate debt securities	$	17,084	$	(161)

U.S. treasury securities	3,666		(14)
Total short-term investments	$	20,750	$	(175)

Components of Property and Equipment

The estimated useful lives of the major classes of property and equipment are as follows:


			Estimated Useful Lives
Furniture and office equipment			3 to 5 years
Leasehold improvements			4 to 6 years
Laboratory equipment			5 years

Property and equipment consisted of the following:


	As of December 31,
(in thousands)	2023		2022
Furniture and office equipment	$	1,067	$	1,066
Leasehold improvements	2,568		2,560
Laboratory equipment	1,355		1,056
Property and equipment, gross	4,990		4,682
Less—accumulated depreciation	(3,752)		(3,413)
Property and equipment, net	$	1,238	$	1,269

Components of Accrued Liabilities

Accrued liabilities consisted of the following:


	As of December 31,
(in thousands)	2023		2022
Accrued compensation	$	2,737	$	1,849

Clinical trials	4,309		2,333
Research agreements and services	530		509




Other accrued liabilities	207		486
Total accrued liabilities	$	7,783	$	5,177

- Definition

Tabular disclosure of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 9
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-9

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
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-Section 50
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-3

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
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-Name Accounting Standards Codification
-Section 50
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-2

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
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-URI https://asc.fasb.org//1943274/2147481800/320-10-50-2

Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
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-URI https://asc.fasb.org//1943274/2147481800/320-10-50-2

Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
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-URI https://asc.fasb.org//1943274/2147481800/320-10-50-2

Reference 8: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
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-Section 50
-Paragraph 2
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-2

Reference 9: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)
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-URI https://asc.fasb.org//1943274/2147481800/320-10-50-3

Reference 10: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
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-URI https://asc.fasb.org//1943274/2147481800/320-10-50-3

Reference 11: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
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-Name Accounting Standards Codification
-Section 50
-Paragraph 3
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-3

Reference 12: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-3

+ Details

Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
Statements of Cash Flows - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Operating activities
Net loss	$ (41,441)	$ (38,704)
Adjustments to reconcile net loss to net cash used in operating activities:
Loss on disposal of assets	0	1
Depreciation	398	236
Stock-based compensation expense	4,509	4,256
(Accretion) amortization of (discounts) and premiums on short-term investments, net	(921)	632
Release of clinical trial funding commitment	0	139
Changes in operating assets and liabilities:
Other assets	108	(1,148)
Accounts receivable and unbilled receivable	483	(236)
Prepaid expenses and other current assets	3,169	(443)
Operating lease right-of-use assets	543	545
Accounts payable and accrued expenses	2,831	1,348
Operating lease liabilities	(566)	(404)
Other liabilities	0	(42)
Net cash used in operating activities	(30,887)	(33,820)
Investing activities
Capital expenditures	(582)	(1,006)
Insurance proceeds from casualty loss	0	114
Maturities of short-term investments	86,552	76,445
Purchases of short-term investments	(70,084)	(91,233)
Sales of short-term investments	20,309	53,829
Net cash provided by investing activities	36,195	38,149
Financing activities
Proceeds from exercise of options	0	75
Net cash provided by financing activities	0	75
Net change in cash and cash equivalents	5,308	4,404
Cash and cash equivalents—Beginning of period	16,347	11,943
Cash and cash equivalents—End of period	21,655	16,347
Supplementary disclosure of cash flow activity:
Cash paid for taxes	1	2
Acquisition of property and equipment included in accounts payable and accrued liabilities	16	232
Supplemental disclosure of non-cash investing and financing activities:
Cumulative preferred stock dividend adjustment	$ 0	$ (414)

Income Taxes - Narrative (Details)	12 Months Ended
Income Taxes - Narrative (Details)	Dec. 31, 2023 USD ($)
Operating loss carryforwards (NOLs)
Interest and/or penalties incurred	$ 0
Federal
Operating loss carryforwards (NOLs)
NOLs, subject to expiration	5,100,000
NOLs, not subject to expiration	99,200,000
California Franchise Tax Board
Operating loss carryforwards (NOLs)
NOLs	22,200,000
R&D credits \| Federal
Operating loss carryforwards (NOLs)
Tax credits	1,600,000
R&D credits \| California Franchise Tax Board
Operating loss carryforwards (NOLs)
Tax credits	$ 2,600,000

Supplementary Balance Sheet Information - Investments Available-for-sale in a Continuous Loss Position (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Debt Securities, Available-for-sale [Line Items]
Fair Market Value	$ 397	$ 20,750
Gross Unrealized Loss	(3)	(175)
Corporate debt securities
Debt Securities, Available-for-sale [Line Items]
Fair Market Value	397	17,084
Gross Unrealized Loss	$ (3)	(161)
U.S. treasury securities
Debt Securities, Available-for-sale [Line Items]
Fair Market Value		3,666
Gross Unrealized Loss		$ (14)

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-2

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (aa)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-2

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (aaa)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-2

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-2

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-2

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-2

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-3

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-3

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-3

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-3

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 320
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481800/320-10-50-3

+ Details

Business Overview and Liquidity	12 Months Ended
Business Overview and Liquidity	Dec. 31, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Business Overview and Liquidity	Business Overview and Liquidity Business Organization and Overview Cardiff Oncology, Inc. (“Cardiff Oncology” or the “Company”) headquartered in San Diego, California, is a clinical-stage biotechnology company leveraging Polo-like Kinase 1 (“PLK1”) inhibition to develop novel therapies across a range of cancers. The Company’s lead asset is onvansertib, a PLK1 inhibitor that is being evaluated in combination with standard of care therapies in clinical programs targeting indications such as RAS-mutated metastatic colorectal cancer (“mCRC”), as well as 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 the standard of care alone. The Company's common stock is listed on the Nasdaq Capital Market under the ticker symbol "CRDF". Liquidity The Company has incurred net losses since its inception and has negative operating cash flows. As of December 31, 2023, the Company had $74.8 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.

Supplementary Balance Sheet Information

12 Months Ended

Dec. 31, 2023

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Supplementary Balance Sheet Information

Short-term investments available-for-sale securities consist of the following:


	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


	As of December 31, 2022
(in thousands)	Amortized Cost		Gross Unrealized Gains		Gross Unrealized Losses		Fair Market Value
Maturity less than 1 year:
Certificate of deposit	$	16,101	$	3	$	(81)	$	16,023
Corporate debt securities	44,806		8		(275)		44,539
Commercial paper	13,203		4		(20)		13,187

U.S. government agencies	2,284		4		—		2,288
U.S. treasury securities	7,905		—		(18)		7,887
Total maturity less than 1 year	84,299		19		(394)		83,924
Maturity 1 to 2 years:
Corporate debt securities	5,016		1		(21)		4,996

Total maturity 1 to 2 years	5,016		1		(21)		4,996

Total short-term investments	$	89,315	$	20	$	(415)	$	88,920

For the year ended December 31, 2023 the net realized loss recorded within the Company's statement of operations from the sale of short-term investments was $0.1 million. The amount of gains and losses reclassified out of other comprehensive income for the period related to the sales of short-term investments was not material for the year ended December 31, 2023.

The Company periodically reviews the 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, the Company has 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 December 31, 2023, were substantially due to increases in interest rates, not due to increased credit risks associated with specific securities. Accordingly, the Company has not recorded an allowance for credit losses. It is not more likely than not that the Company will be required to sell the investments before recovery of their amortized cost bases, which may be at maturity.

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


	As of December 31, 2023
(in thousands)	Fair Market Value		Gross Unrealized Loss

Corporate debt securities	$	397	$	(3)


Total short-term investments	$	397	$	(3)


	As of December 31, 2022
(in thousands)	Fair Market Value		Gross Unrealized Loss

Corporate debt securities	$	17,084	$	(161)

U.S. treasury securities	3,666		(14)
Total short-term investments	$	20,750	$	(175)

Accrued Interest from short-term investments

Accrued interest from short-term investments contained within prepaid expenses and other current assets as of December 31, 2023 and 2022 was $0.6 million and $0.5 million, respectively.

Property and Equipment

Fixed assets consist of furniture and office equipment, leasehold improvements and laboratory equipment. Depreciation expense for property and equipment for the years ended December 31, 2023 and 2022 was $0.4 million and $0.2 million, respectively. Property and equipment consisted of the following:


	As of December 31,
(in thousands)	2023		2022
Furniture and office equipment	$	1,067	$	1,066
Leasehold improvements	2,568		2,560
Laboratory equipment	1,355		1,056
Property and equipment, gross	4,990		4,682
Less—accumulated depreciation	(3,752)		(3,413)
Property and equipment, net	$	1,238	$	1,269

Accrued Liabilities

Accrued liabilities consisted of the following:


	As of December 31,
(in thousands)	2023		2022
Accrued compensation	$	2,737	$	1,849

Clinical trials	4,309		2,333
Research agreements and services	530		509




Other accrued liabilities	207		486
Total accrued liabilities	$	7,783	$	5,177

Derivative Financial Instruments - Warrants (Tables)

12 Months Ended

Dec. 31, 2023

Derivative Instruments and Hedging Activities Disclosure [Abstract]

Schedule of Assumptions Used to Determine the Fair Value of Warrants

The assumptions used to determine the fair value of the warrants using the Black-Scholes option pricing model were:


	As of December 31, 2022
Fair value of Cardiff Oncology common stock	$1.40
Expected warrant term	0.1 years
Risk-free interest rate	4.12	%
Expected volatility of Cardiff Oncology common stock	54	%
Dividend yield	0	%

Schedule of Components of Changes in the Company’s Derivative Financial Instruments Liability Balance


(in thousands, except for number of warrants)
Date	Description	Number of Warrants	Derivative Instrument Liability
December 31, 2021	Balance of derivative financial instruments—warrants liability	64,496	$	285

	Change in fair value of derivative financial instruments—warrants during the year recognized as a gain in the statement of operations	—	(285)
December 31, 2022	Balance of derivative financial instruments—warrants liability	64,496	—
	Expiration of Derivative Financial Instruments	(64,496)	—
	Change in fair value of derivative financial instruments—warrants during the year recognized as a loss in the statement of operations	—	—
December 31, 2023	Balance of derivative financial instruments—warrants liability	—	$	—

Supplementary Balance Sheet Information - Short-term Investments (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Maturity less than 1 year:
Amortized Cost	$ 26,293	$ 84,299
Gross Unrealized Gains	33	19
Gross Unrealized Losses	(17)	(394)
Fair Market Value	26,309	83,924
Maturity 1 to 2 years:
Amortized Cost	26,942	5,016
Gross Unrealized Gains	6	1
Gross Unrealized Losses	(89)	(21)
Fair Market Value	26,859	4,996
Amortized Cost	53,235	89,315
Gross Unrealized Gains	39	20
Gross Unrealized Losses	(106)	(415)
Fair Market Value	53,168	88,920
Certificate of deposit
Maturity less than 1 year:
Amortized Cost	8,317	16,101
Gross Unrealized Gains	16	3
Gross Unrealized Losses	0	(81)
Fair Market Value	8,333	16,023
Corporate debt securities
Maturity less than 1 year:
Amortized Cost	10,948	44,806
Gross Unrealized Gains	8	8
Gross Unrealized Losses	(16)	(275)
Fair Market Value	10,940	44,539
Maturity 1 to 2 years:
Amortized Cost	8,437	5,016
Gross Unrealized Gains	6	1
Gross Unrealized Losses	(10)	(21)
Fair Market Value	8,433	4,996
Commercial paper
Maturity less than 1 year:
Amortized Cost	6,193	13,203
Gross Unrealized Gains	9	4
Gross Unrealized Losses	0	(20)
Fair Market Value	6,202	13,187
U.S. government agencies
Maturity less than 1 year:
Amortized Cost	835	2,284
Gross Unrealized Gains	0	4
Gross Unrealized Losses	(1)	0
Fair Market Value	834	2,288
U.S. treasury securities
Maturity less than 1 year:
Amortized Cost		7,905
Gross Unrealized Gains		0
Gross Unrealized Losses		(18)
Fair Market Value		$ 7,887
Maturity 1 to 2 years:
Amortized Cost	18,505
Gross Unrealized Gains	0
Gross Unrealized Losses	(79)
Fair Market Value	$ 18,426

Stockholders' Equity - Schedule of Warrants (Details) - $ / shares	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Number of Warrants
Balance of warrants outstanding at the beginning of the period (in shares)	4,360,968	4,490,159
Expired (in shares)	(1,553,020)	(129,191)
Balance of warrants outstanding at the end of the period (in shares)	2,807,948	4,360,968	4,490,159
Weighted-Average Exercise Price Per Share
Weighted average exercise price of warrants at the beginning of the period (in dollars per share)	$ 5.33	$ 5.80
Expired (in dollars per share)	10.54	21.60
Weighted average exercise price of warrants at the end of the period (in dollars per share)	$ 2.45	$ 5.33	$ 5.80
Weighted-Average Remaining Contractual Term
Weighted-Average Remaining Contractual Term	1 year 10 months 24 days	2 years 1 month 6 days	3 years

Income Taxes

12 Months Ended

Dec. 31, 2022

Income Tax Disclosure [Abstract]

Income Taxes

At December 31, 2023, Cardiff Oncology had federal net operating loss carryforwards (“NOLs”) of approximately $5.1 million which, if not used, will continue to expire through 2037, and federal net operating loss carryforwards of approximately $99.2 million, which do not expire. Cardiff Oncology also has California NOLs of approximately $22.2 million which, if not used, will begin to expire in 2029. Cardiff Oncology also has research and development tax credits available for federal and California purposes of approximately $1.6 million and $2.6 million, respectively. The federal research and development tax credits will begin to expire on January 31, 2025. The California research and development tax credits do not expire.

Pursuant to the Internal Revenue Code of 1986, as amended (the “Code”) Sections 382 and 383, annual use of a company’s NOL and research and development credit carryforwards may be limited if there is a cumulative change in ownership of greater than 50% within a three-year period. The amount of the annual limitation is determined based on the value of the Company immediately prior to the ownership change. Subsequent ownership changes may further affect the limitation in future years. If limited, the related tax asset would be removed from the deferred tax asset schedule with a corresponding reduction in the valuation allowance. The Company has established a valuation allowance as the realization of such deferred tax assets has not met the more likely than not threshold requirement. Due to the existence of the valuation allowance, further changes in the Company’s unrecognized tax benefits will not impact the Company’s effective tax rate.

The provision for income taxes based on losses from continuing operations consists of the following at December 31:


	Years ended December 31,
(in thousands)	2023		2022
Current:

State	$	—	$	—
Total current provision	—		—
Deferred:
Federal	(8,300)		19,054
State	(789)		4,902

Total deferred (benefit) expense	(9,089)		23,956
Valuation allowance	9,089		(23,956)
Total income tax provision	$	—	$	—

Significant components of the Company’s taxes and the rates as of December 31 are shown below:


	Years ended December 31,
(in thousands, except percentages)	2023				2022
Tax computed at the federal statutory rate	$	(8,703)	21	%	$	(8,128)	21	%
State tax, net of federal tax benefit	(645)		2	%	(518)		1	%

Permanent items	(2)		—	%	32,369		(84)	%
Stock based compensation	902		(2)	%	553		(1)	%
Research and development credits	(515)		1	%	(319)		1	%

Other	(126)		—	%	(1)		—	%
Valuation allowance increase (decrease)	9,089		(22)	%	(23,956)		62	%

Provision for income taxes	$	—	—	%	$	—	—	%

Significant components of the Company’s deferred tax assets and liabilities from federal and state income taxes as of December 31 are shown below (in thousands):


	Years ended December 31,
(in thousands)	2023		2022
Deferred tax assets:
Tax loss carryforwards	$	23,441	$	20,289
Research and development credits and other tax credits	3,611		2,743
Stock-based compensation	1,407		1,317
Capitalized research and development	9,687		4,794
Other	1,400		1,431
Total deferred tax assets	39,546		30,574
Deferred tax liabilities:
Operating lease right-of-use assets	(375)		(492)

Total deferred tax liabilities	(375)		(492)
Net deferred tax assets before valuation allowance	39,171		30,082
Valuation allowance	(39,171)		(30,082)
Net deferred tax asset	$	—	$	—

Since inception the Company has incurred continuing losses and expects to continue to incur losses for the foreseeable future. The Company has recorded a full valuation allowance against its net deferred tax assets as it is more likely than not they will not be realized.

Cardiff Oncology does not have any unrecognized tax benefits. Cardiff Oncology’s practice is to recognize interest and/or penalties related to income tax matters in income tax expense, and none have been incurred to date. The Company does not anticipate a significant change in unrecognized tax benefits over the next 12 months. The Company is subject to taxation in the U.S. and California. Due to net operating losses all tax years since inception remain open to examination.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480990/946-20-50-13

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(h)(2))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org//740/tableOfContent

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-14

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 21
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-21

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 270
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482526/740-270-50-1

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 17
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-17

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
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-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 6.I.5.Q1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479360/740-10-S99-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 11.C)
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-URI https://asc.fasb.org//1943274/2147479360/740-10-S99-2

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
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-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482603/740-30-50-2

+ Details

Leases - Future Minimum Lease Payments (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Operating Leases
2024	$ 691
2025	775
2026	796
2027	136
Thereafter	0
Total future minimum lease payments	2,398
Less imputed interest	(249)
Total	$ 2,149	$ 2,715

Audit Information	12 Months Ended
Audit Information	Dec. 31, 2023
Audit Information [Abstract]
Auditor Firm ID	243
Auditor Name	BDO USA, P.C.
Auditor Location	San Diego, California

Commitments and Contingencies	12 Months Ended
Commitments and Contingencies	Dec. 31, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Executive Agreements Certain executive agreements provide for severance payments in case of terminations without cause or certain change of control scenarios. Research and Development and Clinical Trial 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 years ended December 31, 2023 and 2022, no milestone or royalty payments were made. The Company is a party of various agreements under which it licenses technology on an exclusive basis in the field of oncology therapeutics. These agreements include License fees, Royalties and Milestone payments. The company also has a legacy license agreement in the field of oncology diagnostics under which royalty payments are due. These royalty payments are calculated as a percent of revenue. During the years ended December 31, 2023 and 2022 payments have not been material. Litigation Cardiff Oncology does not believe that it has legal liabilities that are probable or reasonably possible that require either accrual or disclosure. From time to time, the Company may become involved in various lawsuits and legal proceedings that arise in the ordinary course of business. Litigation is subject to inherent uncertainties, and an adverse result in matters may arise from time to time that may harm the Company’s business. As of the date of this report, management believes that there are no claims against the Company, which it believes will result in a material adverse effect on the Company’s business or financial condition.

Stock-Based Compensation (Tables)

12 Months Ended

Dec. 31, 2023

Share-Based Payment Arrangement [Abstract]

Stock-based compensation recognized

Stock-based compensation has been recognized in operating results as follows:


(in thousands)	Years ended December 31,
	2023		2022

Research and development expenses	$	1,279	$	1,035

Selling, general and administrative expenses	3,230		3,221

Total stock-based compensation	$	4,509	$	4,256

Estimated Fair Value of Stock Options - Assumptions

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 assumptions during the years indicated below:


	Years ended December 31,
	2023	2022
Risk-free interest rate (range)	3.56% - 4.06%	1.62% - 3.75%
Dividend yield	0%	0%
Expected volatility (range)	105% - 110%	98% - 110%
Expected volatility (weighted-average)	109%	106%
Expected term (in years)	5.2 years	6.0 years

Summary of Stock Option Activity

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


	Number of Options	Weighted-Average Exercise Price Per Share		Intrinsic Value		Weighted-Average Remaining Contractual Life














Balance outstanding, December 31, 2022	5,069,458	$	5.92	$	19,322	7.4 years
Granted	2,138,624	$	1.70


Forfeited and expired	(557,128)	$	9.43
Balance Outstanding, December 31, 2023	6,650,954	$	4.27	$	23,926	7.9 years
Vested and exercisable, December 31, 2023	3,124,492	$	5.66	$	22,456	6.9 years
Vested and expected to vest, December 31, 2023	6,462,464	$	4.33	$	23,853	7.8 years

Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Statement of Comprehensive Income [Abstract]
Net loss	$ (41,441)	$ (38,704)
Unrealized gain (loss) on securities available-for-sale	328	(253)
Total comprehensive loss	(41,113)	(38,957)
Preferred stock dividend payable on Series A Convertible Preferred Stock	(24)	(24)
Comprehensive loss attributable to common stockholders	$ (41,137)	$ (38,981)

- Definition

The portion of profit or loss for the period, net of income taxes, which is attributable to the parent.

+ References

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+ Details

Balance Sheets (Parenthetical) - USD ($) shares in Thousands, $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	20,000	20,000
Liquidation preference - Series A Convertible Preferred Stock	$ 1,068	$ 1,044
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized (in shares)	150,000	150,000
Common stock, shares issued (in shares)	44,677	44,677
Common stock, shares outstanding (in shares)	44,677	44,677

Supplementary Balance Sheet Information - Property and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Property and equipment	$ 4,990	$ 4,682
Less—accumulated depreciation	(3,752)	(3,413)
Property and equipment, net	1,238	1,269
Furniture and office equipment
Property, Plant and Equipment [Line Items]
Property and equipment	1,067	1,066
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment	2,568	2,560
Laboratory equipment
Property, Plant and Equipment [Line Items]
Property and equipment	$ 1,355	$ 1,056

Basis of Presentation and Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2023

Accounting Policies [Abstract]

Useful Life of Property and Equipment

The estimated useful lives of the major classes of property and equipment are as follows:


			Estimated Useful Lives
Furniture and office equipment			3 to 5 years
Leasehold improvements			4 to 6 years
Laboratory equipment			5 years

Property and equipment consisted of the following:


	As of December 31,
(in thousands)	2023		2022
Furniture and office equipment	$	1,067	$	1,066
Leasehold improvements	2,568		2,560
Laboratory equipment	1,355		1,056
Property and equipment, gross	4,990		4,682
Less—accumulated depreciation	(3,752)		(3,413)
Property and equipment, net	$	1,238	$	1,269

Schedule of Antidilutive Securities Excluded from the Calculation of Basic and Diluted Loss Per Share

Shares used in calculating diluted net loss per common share exclude as anti-dilutive the following share equivalents:


	December 31,
	2023	2022
Options to purchase Common Stock	6,650,954	5,069,458
Warrants to purchase Common Stock	2,807,948	4,360,968


Series A Convertible Preferred Stock	877	877

	9,459,779	9,431,303

Basis of Presentation and Summary of Significant Accounting Policies

12 Months Ended

Dec. 31, 2023

Accounting Policies [Abstract]

Basis of Presentation and Summary of Significant Accounting Policies

The accompanying financial statements of Cardiff Oncology have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”).

Segment Reporting

Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision-maker regarding resource allocation and assessing performance. The Company views its operations and manages its business, as one operating segment in the United States.

Use of Estimates

The preparation of financial statements in conformity with U.S. GAAP requires management to make significant estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. The most significant estimate involves accrued clinical trial expenses.

Accrued Clinical Trial Expenses

The Company expenses research and development expenditures as incurred, which include costs related to clinical trial activities. The Company accrues costs for clinical trial activities based upon estimates of the services received and related expenses incurred that have yet to be invoiced by the Clinical Research Organizations ("CROs"), investigators, professional service providers, and other vendors providing clinical trial services (collectively, the “service providers”). As of December 31, 2023 the Company’s clinical trial accrual balance of $4.3 million is included in accrued liabilities. The Company’s related 2023 clinical trial expenses are included in research and development expense.

Cash and Cash Equivalents

The Company considers all highly liquid investments with original maturities of three months or less from the date of purchase to be cash equivalents. Cash and cash equivalents consist of cash in readily available checking and money market accounts.

Investment Securities

All investments have been classified as “available-for-sale” and are carried at fair value as determined based upon quoted market prices or pricing models for similar securities at period end. Investments with contractual maturities less than 12 months at the balance sheet date are considered short-term investments. Investments with contractual maturities beyond one year are also classified as short-term due to the Company’s ability to liquidate the investment for use in operations within the next 12 months.

Realized gains and losses on investment securities are included in earnings and are derived using the specific identification method for determining the cost of securities sold. The Company has not realized any significant gains or losses on sales of available-for-sale investment securities during any of the periods presented. As all the Company’s investment holdings are in the form of debt securities or certificates of deposit, unrealized gains and losses that are determined to be temporary in nature are reported as a component of accumulated other comprehensive loss. A decline in the fair value of any security below cost that is deemed other than temporary results in a charge to earnings and the establishment of a new cost basis for the security. Interest income is recognized when earned and is included in investment income, as are the amortization of purchase premiums and accretion of purchase discounts on investment securities.

Concentration of Credit Risk

Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash, cash equivalents and short-term investments.

Cash and cash equivalents

The Company maintains deposit accounts at financial institutions that are in excess of federally insured limits. The Company has not experienced any losses in such accounts and believes it is not exposed to significant risk on its cash due to the financial position of the depository institution in which those deposits are held. The Company limits its exposure to credit loss by generally placing its cash in high credit quality financial institutions and investment in non FDIC insured money market funds denominated and payable in U.S. dollars.

Short-term investments

The Company follows an investment policy which requires short-term investments to be diversified across different types of instruments and issuers. The investment policy also requires investments to be in high quality instruments. The diversification and credit quality requirements of the Company's investment policy limits its exposure to credit loss.

Revenues

The Company recognizes revenue when control of its products and services are transferred to its customers in an amount that reflects the consideration it expects to receive from its customers in exchange for those products and services. This process involves identifying the contract with a customer, determining the performance obligations in the contract, determining the contract price, allocating the contract price to the distinct performance obligations in the contract, and recognizing revenue when the performance obligations have been satisfied. A performance obligation is considered distinct from other obligations in a contract when it provides a benefit to the customer either on its own or together with other resources that are readily available to the customer and is separately identified in the contract. The Company considers a performance obligation satisfied once it has transferred control of goods or service to the customer, meaning the customer has the ability to use and obtain the benefit of goods or service. The Company recognizes revenue for satisfied performance obligations only when it determines there are no uncertainties regarding payment terms or transfer of control. For sales-based royalties, the Company recognizes revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied).

Royalty and License Revenues

The Company licenses and sublicenses its patent rights to healthcare companies, medical laboratories and biotechnology partners. These patents are from the Company's legacy portfolio and unrelated to onvansertib. Agreements may involve multiple elements such as license fees, minimum royalties, usage-based royalties and milestone payments. Revenue is recognized when the criteria described above have been met as well as the following:

•Up-front nonrefundable license fees pursuant to agreements under which the Company has no continuing performance obligations are recognized as revenues on the effective date of the agreement and when collection is probable.

•Minimum royalties are recognized as earned, and royalties are earned based on the licensee’s use. The Company estimates and records licensee’s sales based on historical usage rate and collectability.

•For sales-based royalties, we recognize revenue at the later of (i) when the related sales occur, or (ii) when the performance obligation to which some or all of the royalty has been allocated has been satisfied (or partially satisfied).

Payment terms and conditions vary by contracts, although terms generally include a requirement of payment within 30 to 45 days after invoice. Royalties are generally due quarterly or annually.

Derivative Financial Instruments—Warrants

The Company has issued common stock warrants in connection with the execution of certain equity financings. Such warrants are classified as derivative liabilities and are recorded at their fair market value as of each reporting period as they do not meet the criteria for equity classification. Changes in fair value of derivative liabilities are recorded in the statement of operations under the caption “Change in fair value of derivative instruments—warrants.”

The fair value of warrants is determined using the Black-Scholes option-pricing model using assumptions regarding the historical volatility of Cardiff Oncology’s common stock price, the remaining life of the warrants, and the risk-free interest rates at each period end. The Company thus uses model-derived valuations where inputs are observable in active markets to determine the

fair value. The use of the Black-Scholes model classifies such warrants as Level 3 (See "Fair Value of Financial Instruments" below). These warrants expired during the first quarter of 2023. At December 31, 2022, the fair value of these warrants was $0.

Stock-Based Compensation

Stock-based compensation expense is measured at the grant date based on the estimated fair value of the award and is recognized straight-line over the requisite service period of the individual grants, which typically equals the vesting period.

Fair Value of Financial Instruments

Financial instruments consist of cash equivalents, accounts receivable, and accounts payable. The Company applies ASC 820 for financial assets and liabilities that are required to be measured at fair value and non-financial assets and liabilities that are not required to be measured at fair value on a recurring basis. These financial instruments are stated at their respective historical carrying amounts, which approximate fair value due to their short-term nature as they reflect current market interest rates.

The authoritative guidance establishes a fair value hierarchy that is based on the extent and level of judgment used to estimate the fair value of assets and liabilities. In general, the authoritative guidance requires us to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. An asset or liability’s categorization within the fair value hierarchy is based upon the lowest level of input that is significant to the measurement of its fair value. The three levels of input defined by the authoritative guidance are as follows:

The Company measures certain assets and liabilities at fair value on a recurring basis using the three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value. The three tiers include:

•Level 1 — Quoted prices for identical instruments in active markets.

•Level 2 — Quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active; and model-derived valuations where inputs are observable or where significant value drivers are observable.

•Level 3 — Instruments where significant value drivers are unobservable to third parties.

Long-Lived Assets

Long-lived assets consist of property, equipment and lease right-of-use assets. The Company records property and equipment at cost. Depreciation on property and equipment is calculated using the straight-line method over the estimated useful life of the asset. Depreciation of leasehold improvements is computed based on the shorter of the life of the asset or the term of the lease. The estimated useful lives of the major classes of property and equipment are as follows:


			Estimated Useful Lives
Furniture and office equipment			3 to 5 years
Leasehold improvements			4 to 6 years
Laboratory equipment			5 years

Impairment losses on long-lived assets used in operations are recorded when indicators of impairment are present and the undiscounted cash flows estimated to be generated by those assets are less than the assets carrying amount. If such assets are considered to be impaired, the impairment to be recognized is measured by the amount by which the carrying amount of the assets exceeds the estimated fair value of the assets.

Leases

The Company determines if an arrangement is a lease at inception. Operating leases are included in operating lease Right-of-Use (“ROU”) assets, current operating lease liabilities and non-current operating lease liabilities in the Company’s balance sheets.

ROU assets represent the Company’s right to use an underlying asset for the lease term and lease liabilities represent its obligation to make lease payments arising from the lease. Operating lease ROU assets and liabilities are recognized at

commencement date based on the present value of lease payments over the lease term. None of the Company’s operating leases provide an implicit rate, therefore the Company uses its incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments. The incremental borrowing rate is the rate of interest that the Company would expect to pay to borrow on a collateralized and fully amortizing basis over a similar term an amount equal to the lease payments in a similar economic environment. The operating lease ROU asset also includes any lease payments made less lease incentives received. The Company’s lease terms may include options to extend or terminate the lease when it is reasonably certain that the Company will exercise that option. Lease expense is recognized on a straight-line basis over the lease term. Our facilities lease agreement contains lease and non-lease components, such as common area maintenance. We have elected to account for these lease and non-lease components of this agreement as a single lease component.

Leases with an initial term of 12 months or less are not recorded on the Company's balance sheets. These short-term leases are expensed on a straight-line basis over the lease term.

Income Taxes

Income taxes are determined using the asset and liability approach of accounting for income taxes. Under this approach, deferred taxes represent the future tax consequences expected to occur when the reported amounts of assets and liabilities are recovered or paid. Deferred taxes result from differences between the financial statement and tax bases of Cardiff Oncology’s assets and liabilities and are adjusted for changes in tax rates and tax laws when changes are enacted. Valuation allowances are recorded to reduce deferred tax assets when it is more likely than not that a tax benefit will not be realized. The assessment of whether or not a valuation allowance is required often requires significant judgment.

Contingencies

In the normal course of business, the Company is subject to loss contingencies, such as legal proceedings and claims arising out of its business, that cover a wide range of matters, including, among others, government investigations, stockholder lawsuits, product and environmental liability, and tax matters. In accordance with FASB ASC Topic 450, Contingencies, the Company records such loss contingencies when it is probable that a liability has been incurred and the amount of loss can be reasonably estimated. The Company, in accordance with this guidance, does not recognize gain contingencies until realized.

Research and Development

Research and development expenses include expenditures in connection with an in-house research and development laboratory, salaries and staff costs, clinical trials, purchased in-process research and development and regulatory and scientific consulting fees, as well as contract research and insurance. Also, patent filing and patent maintenance expenses are considered legal in nature and therefore classified as general and administrative expense, if any.

Non-refundable advance payments for goods or services that will be used or rendered for future research and development activities are deferred and capitalized. As the related goods are delivered or the services are performed, or when the goods or services are no longer expected to be provided, the deferred amounts are recognized as an expense.

Upfront and milestone payments to acquire contractual rights to licensed technology are expensed when incurred if there is uncertainty in the Company receiving future economic benefit from the acquired contractual rights. Certain contractual rights may require the Company to make additional milestone payments based on development and commercial milestones, and royalties based on sales volume. See Note 10 - Commitments and Contingencies, for further details.

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.

Net Loss Per Share

Basic and diluted net loss per common share is determined by dividing net loss attributable to common stockholders by the weighted-average common shares outstanding during the period. The accretion of Series A Convertible Preferred Stock dividends and deemed dividends recognized in connection with certain preferred share issuances are included in net loss attributable to common stockholders in the computation of basic and diluted earnings per share. For all periods presented, there is no difference in the number of shares used to calculate basic and diluted shares outstanding as inclusion of the potentially dilutive securities would be antidilutive. Shares used in calculating diluted net loss per common share exclude as anti-dilutive the following share equivalents:


	December 31,
	2023	2022
Options to purchase Common Stock	6,650,954	5,069,458
Warrants to purchase Common Stock	2,807,948	4,360,968


Series A Convertible Preferred Stock	877	877

	9,459,779	9,431,303

Recently Adopted Accounting Pronouncement

In May 2021, the Financial Accounting Standards Board ("FASB") issued Accounting Standard Update ("ASU") No. 2021-04 ("ASU 2021-04"), Earnings Per Share (Topic 260), Debt—Modifications and Extinguishments (Subtopic 470-50), Compensation—Stock Compensation (Topic 718), and Derivatives and Hedging—Contracts in Entity’s Own Equity (Subtopic 815-40): Issuer’s Accounting for Certain Modifications or Exchanges of Freestanding Equity-Classified Written Call Options (a consensus of the FASB Emerging Issues Task Force). The amendments in this update are effective for all entities for fiscal years beginning after December 15, 2021, including interim periods within those fiscal years. The Company has prospectively adopted this standard as of January 1, 2022 for periods presented after the adoption. The adoption of ASU 2021-04 did not have a material impact on the Company's financial statements.

Recent Accounting Pronouncement Not Yet Adopted

In August 2020, the FASB issued ASU No. 2020-06 ("ASU 2020-06"), Debt – Debt with Conversion and Other Options (Subtopic 470-20) and Derivatives and Hedging – Contracts in Entity’s Own Equity (Subtopic 815-40) (“ASU 2020-06”). ASU 2020-06 eliminates the beneficial conversion and cash conversion accounting models for convertible instruments. It also amends the accounting for certain contracts in an entity’s own equity that are currently accounted for as derivatives because of specific settlement provisions. In addition, ASU 2020-06 modifies how particular convertible instruments and certain contracts that may be settled in cash or shares impact the diluted EPS computation. The amendments in this update are effective for 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 will adopt this standard as of January 1, 2024 using the modified-retrospective method. The Company is currently evaluating the adoption of ASU 2020-06, but does not expect it to have a material impact on the Company's financial statements.

In December 2023, the FASB issued ASU No. 2023-09 ("ASU 2023-09"), “Improvements to Income Tax Disclosures.” ASU 2023-09 requires disaggregated information about a reporting entity’s effective tax rate reconciliation as well as information on income taxes paid. ASU 2023-09 is effective for public entities with annual periods beginning after December 15, 2024 and for private businesses for annual periods beginning after December 15, 2025, with early adoption permitted. The Company is currently evaluating the impact of this guidance on its financial statement disclosures.

Employee Benefit Plan	12 Months Ended
Employee Benefit Plan	Dec. 31, 2023
Retirement Benefits [Abstract]
Employee Benefit Plan	Employee Benefit Plan The Company has a defined contribution retirement plan under Section 401(k) of the Internal Revenue Service ("IRS") Code covering its employees. The plan allows employees to defer, up to the maximum allowed, a percentage of their income through contributions to the plan as allowed by IRS Code. The Company does not currently make matching contributions.

- Definition

The entire disclosure for retirement benefits.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

Stockholders' Equity (Tables)

12 Months Ended

Dec. 31, 2023

Stockholders' Equity Note [Abstract]

Summary of Warrant Activity and Changes in Warrants Outstanding

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


	Number of Warrants	Weighted-Average Exercise Price Per Share		Weighted-Average Remaining Contractual Term












Balance outstanding, December 31, 2021	4,490,159	$	5.80	3.0 years


Expired	(129,191)	$	21.60
Balance outstanding, December 31, 2022	4,360,968	$	5.33	2.1 years
Expired	(1,553,020)	$	10.54
Balance outstanding, December 31, 2023	2,807,948	$	2.45	1.9 years

Schedule of Preferred Stock

The components of the liquidation preference for the Series A Convertible Preferred Stock were as follows:


	As of December 31,
(in thousands)	2023		2022
Stated Value per share liquidation	$	606	$	606
Cumulative unpaid preferred stock dividends	462		438
Liquidation preference - Series A Convertible Preferred Stock	$	1,068	$	1,044

- Definition

Tabular disclosure of an entity's stock, including par or stated value per share, number and dollar amount of share subscriptions, shares authorized, shares issued, shares outstanding, number and dollar amount of shares held in an employee trust, dividend per share, total dividends, share conversion features, par value plus additional paid in capital, the value of treasury stock and other information necessary to a fair presentation, and EPS information. Stock by class includes common, convertible, and preferred stocks which are not redeemable or redeemable solely at the option of the issuer. Includes preferred stock with redemption features that are solely within the control of the issuer and mandatorily redeemable stock if redemption is required to occur only upon liquidation or termination of the reporting entity. If more than one issue is outstanding, state the title of each issue and the corresponding dollar amount; dollar amount of any shares subscribed but unissued and the deduction of subscriptions receivable there from; number of shares authorized, issued, and outstanding.

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+ Details

Stock-Based Compensation - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Jun. 09, 2022	Jun. 30, 2021
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)			5,150,000	3,150,000
Share-based payment arrangement, plan modification, incremental cost	$ 0.6
Incremental stock compensation	0.1
Fair value of shares vested	$ 4.8	$ 4.7
Inducement Grant Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	1,435,256
Options to purchase Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	2,138,624
Weighted average grant date fair value (in dollars per share)	$ 1.35	$ 2.55
Unrecognized compensation cost for non-vested options	$ 6.6
Period for recognition	2 years 1 month 6 days
Equity Incentive Plan 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares available for issuance (in shares)	2,013,871

Fair Value Measurements

12 Months Ended

Dec. 31, 2023

Fair Value Disclosures [Abstract]

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 December 31, 2023 and 2022:


	Fair Value Measurements at December 31, 2023
(in thousands)	Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Assets:
Money market fund	$	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


	Fair Value Measurements at December 31, 2022
(in thousands)	Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Assets:
Money market fund	$	15,722	$	—	$	—	$	15,722

Total included in cash and cash equivalents	$	15,722	$	—	$	—	$	15,722

Available for sale investments:
Certificate of deposit	$	—	$	16,023	$	—	$	16,023
Corporate debt securities	—		49,535		—		49,535
Commercial paper	—		13,187		—		13,187

U.S. government agencies	—		2,288		—		2,288
U.S. treasury securities	7,887		—		—		7,887
Total available for sale investments	$	7,887	$	81,033	$	—	$	88,920

Total assets measured at fair value on a recurring basis	$	23,609	$	81,033	$	—	$	104,642

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 years ended December 31, 2023 and 2022.

- Definition

The entire disclosure for the fair value of financial instruments (as defined), including financial assets and financial liabilities (collectively, as defined), and the measurements of those instruments as well as disclosures related to the fair value of non-financial assets and liabilities. Such disclosures about the financial instruments, assets, and liabilities would include: (1) the fair value of the required items together with their carrying amounts (as appropriate); (2) for items for which it is not practicable to estimate fair value, disclosure would include: (a) information pertinent to estimating fair value (including, carrying amount, effective interest rate, and maturity, and (b) the reasons why it is not practicable to estimate fair value; (3) significant concentrations of credit risk including: (a) information about the activity, region, or economic characteristics identifying a concentration, (b) the maximum amount of loss the entity is exposed to based on the gross fair value of the related item, (c) policy for requiring collateral or other security and information as to accessing such collateral or security, and (d) the nature and brief description of such collateral or security; (4) quantitative information about market risks and how such risks are managed; (5) for items measured on both a recurring and nonrecurring basis information regarding the inputs used to develop the fair value measurement; and (6) for items presented in the financial statement for which fair value measurement is elected: (a) information necessary to understand the reasons for the election, (b) discussion of the effect of fair value changes on earnings, (c) a description of [similar groups] items for which the election is made and the relation thereof to the balance sheet, the aggregate carrying value of items included in the balance sheet that are not eligible for the election; (7) all other required (as defined) and desired information.

+ References + Details

Supplementary Balance Sheet Information - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Realized loss	$ 0.1
Interest receivable, current	0.6	$ 0.5
Depreciation and amortization	$ 0.4	$ 0.2

Income Taxes - Significant Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Deferred tax assets:
Tax loss carryforwards	$ 23,441	$ 20,289
Research and development credits and other tax credits	3,611	2,743
Stock-based compensation	1,407	1,317
Capitalized research and development	9,687	4,794
Other	1,400	1,431
Total deferred tax assets	39,546	30,574
Deferred tax liabilities:
Operating lease right-of-use assets	(375)	(492)
Total deferred tax liabilities	(375)	(492)
Net deferred tax assets before valuation allowance	39,171	30,082
Valuation allowance	(39,171)	(30,082)
Net deferred tax asset	$ 0	$ 0

Leases (Tables)

12 Months Ended

Dec. 31, 2023

Leases [Abstract]

Summary of Lease Expense and Supplemental Cash Flow Information

The components of lease expense were as follows:


(in thousands)	Twelve Months Ended December 31, 2023		Twelve Months Ended December 31, 2022
Operating lease cost	$	714	$	754

Net operating lease cost	$	714	$	754

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


(in thousands)	Twelve Months Ended December 31, 2023		Twelve Months Ended December 31, 2022
Cash paid for amounts included in the measurement of lease liabilities:
Cash paid included in operating cash flows	$	737	$	612

Supplemental Balance Sheet Information

Supplemental balance sheet information related to leases was as follows:


(in thousands)	As of December 31, 2023			As of December 31, 2022
Operating lease ROU assets	$	1,708		$	2,251

Current operating lease liabilities	$	691		$	675
Non-current operating lease liabilities	1,458			2,040
Total operating lease liabilities	$	2,149		$	2,715

Weighted-average remaining lease term–operating leases	3.2 years			4.2 years
Weighted-average discount rate–operating leases	7		%	7		%

Summary of Future Minimum Lease Payments

Total remaining annual commitments under non-cancelable operating lease agreements as of December 31, 2023, are summarized are as follows:


(in thousands)
Year Ending December 31,	Operating Leases




2024	$	691
2025	775
2026	796
2027	136
Thereafter	—
Total future minimum lease payments	$	2,398
Less imputed interest	(249)
Total	$	2,149

Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Current assets:
Cash and cash equivalents	$ 21,655	$ 16,347
Short-term investments	53,168	88,920
Accounts receivable and unbilled receivable	288	771
Prepaid expenses and other current assets	2,301	5,246
Total current assets	77,412	111,284
Property and equipment, net	1,238	1,269
Operating lease right-of-use assets	1,708	2,251
Other assets	1,279	1,387
Total Assets	81,637	116,191
Current liabilities:
Accounts payable	1,966	1,956
Accrued liabilities	7,783	5,177
Operating lease liabilities	691	675
Total current liabilities	10,440	7,808
Operating lease liabilities, net of current portion	1,458	2,040
Total liabilities	11,898	9,848
Commitments and contingencies
Stockholders’ equity
Preferred stock, $0.001 par value, 20,000 shares authorized; Series A Convertible Preferred Stock liquidation preference $1,068 and $1,044 at December 31, 2023 and December 31, 2022, respectively; (Note 5)	0	0
Common stock, $0.0001 par value, 150,000 shares authorized; 44,677 shares issued and outstanding at December 31, 2023 and December 31, 2022	4	4
Additional paid-in capital	409,343	404,834
Accumulated other comprehensive loss	(67)	(395)
Accumulated deficit	(339,541)	(298,100)
Total stockholders’ equity	69,739	106,343
Total Liabilities and Stockholders’ Equity	$ 81,637	$ 116,191

Document and Entity Information - USD ($)	12 Months Ended
Document and Entity Information - USD ($)	Dec. 31, 2023	Feb. 22, 2024	Jun. 30, 2023
Document and Entity Information
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2023
Current Fiscal Year End Date	--12-31
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, State or Province	CA
Entity Address, City or Town	San Diego
Entity Address, Address Line One	11055 Flintkote Avenue
Entity Address, Postal Zip Code	92121
City Area Code	858
Local Phone Number	952-7570
Title of 12(b) Security	Common Stock, $0.0001 par value
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	true
ICFR Auditor Attestation Flag	false
Document Financial Statement Error Correction [Flag]	false
Entity Shell Company	false
Entity Public Float			$ 64,335,342
Entity Common Stock, Shares Outstanding (shares)		44,677,169
Documents Incorporated by Reference	DOCUMENTS INCORPORATED BY REFERENCE Specified portions of the registrant's proxy statement, which will be filed with the Securities and Exchange Commission pursuant to Regulation 14 A in connection with the registrant's 2023 Annual Meeting of Stockholders (the "Proxy Statement"), are incorporated by reference into Part III of this Annual Report on Form 10-K. Except with respect to information specifically incorporated by reference in this Annual Report, the Proxy Statement is not deemed to be filed as part hereof.
Entity Central Index Key	0001213037
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	FY
Amendment Flag	false

Leases - Narrative (Details) - USD ($)	12 Months Ended	62 Months Ended
Leases - Narrative (Details) - USD ($)	Dec. 31, 2022	Feb. 28, 2027
Lessee, Lease, Description [Line Items]
Monthly rent payments	$ 63,000
Forecast
Lessee, Lease, Description [Line Items]
Annual rent increase, percentage		3.00%

Stockholders' Equity

12 Months Ended

Dec. 31, 2023

Stockholders' Equity Note [Abstract]

Stockholders' Equity

Stockholders’ Equity

Warrants

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


	Number of Warrants	Weighted-Average Exercise Price Per Share		Weighted-Average Remaining Contractual Term












Balance outstanding, December 31, 2021	4,490,159	$	5.80	3.0 years


Expired	(129,191)	$	21.60
Balance outstanding, December 31, 2022	4,360,968	$	5.33	2.1 years
Expired	(1,553,020)	$	10.54
Balance outstanding, December 31, 2023	2,807,948	$	2.45	1.9 years

Series A Convertible Preferred Stock

The material terms of the Series A Convertible Preferred Stock consist of:

1)Dividends. Holders of the Company’s Series A Convertible Preferred Stock are entitled to receive cumulative dividends at the rate per share of 4% per annum, payable quarterly on March 31, June 30, September 30 and December 31, beginning with September 30, 2005. Dividends are payable, at the Company’s sole election, in cash or shares of common stock. As of December 31, 2023 and 2022, the Company had $462,000 and $438,000, respectively in cumulative unpaid preferred stock dividends, included in the liquidation preference of the Series A Convertible Preferred Stock, and $24,000 and $24,000 of cumulative dividends were added to the liquidation preference of the Series A Convertible Preferred Stock during the years ended December 31, 2023 and 2022, respectively.

2)Voting Rights. Shares of the Series A Convertible Preferred Stock have no voting rights. However, so long as any shares of Series A Convertible Preferred Stock are outstanding, the Company may not, without the affirmative vote of the holders of the shares of Series A Convertible Preferred Stock then outstanding, (a) adversely change the powers, preferences or rights given to the Series A Convertible Preferred Stock, (b) authorize or create any class of stock senior or equal to the Series A Convertible Preferred Stock, (c) amend its certificate of incorporation or other charter documents, so as to affect adversely any rights of the holders of Series A Convertible Preferred Stock or (d) increase the authorized number of shares of Series A Convertible Preferred Stock.

3)Liquidation. Upon any liquidation, dissolution or winding-up of the Company, the holders of the Series A Convertible Preferred Stock are entitled to receive an amount equal to the Stated Value per share, which is currently $10 per share plus any accrued and unpaid dividends.

4)Conversion Rights. Each share of Series A Convertible Preferred Stock is convertible at the option of the holder into that number of shares of common stock determined by dividing the Stated Value, currently $10 per share, by the conversion price, which at the time of issuance was $928.80 per share, and subsequently adjusted to $691.20 per share.

5)Subsequent Equity Sales. The conversion price is subject to adjustment for dilutive issuances for a period of 12 months beginning March 17, 2006 and the conversion price was adjusted to $691.20 per share.

6) Automatic Conversion. If the price of the Company’s common stock equals $1,857.60 per share for 20 consecutive trading days, and an average of 116 shares of common stock per day are traded during the 20 trading days, the Company will have the right to deliver a notice to the holders of the Series A Convertible Preferred Stock, requesting the holders to convert any portion of the shares of Series A Convertible Preferred Stock into shares of common stock at the applicable conversion price. As of the date of these financial statements, such conditions have not been met.

The components of the liquidation preference for the Series A Convertible Preferred Stock were as follows:


	As of December 31,
(in thousands)	2023		2022
Stated Value per share liquidation	$	606	$	606
Cumulative unpaid preferred stock dividends	462		438
Liquidation preference - Series A Convertible Preferred Stock	$	1,068	$	1,044

- Definition

The entire disclosure for equity.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Name Accounting Standards Codification
-Section 50
-Paragraph 13
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Name Accounting Standards Codification
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-Paragraph 14
-Subparagraph (b)
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Reference 4: http://www.xbrl.org/2003/role/disclosureRef
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 235
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (d)
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-URI https://asc.fasb.org//1943274/2147481062/946-235-50-2

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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-SubTopic 40
-Name Accounting Standards Codification
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-Paragraph 6
-Subparagraph (a)
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480008/505-10-S99-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(e)(1))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

Reference 10: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 505
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org//505/tableOfContent

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
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Reference 12: http://www.xbrl.org/2003/role/disclosureRef
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-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Name Accounting Standards Codification
-Section 50
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-Subparagraph (i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-13

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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-URI https://asc.fasb.org//1943274/2147481112/505-10-50-14

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
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Reference 16: http://www.xbrl.org/2003/role/disclosureRef
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Reference 17: http://www.xbrl.org/2003/role/disclosureRef
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Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 505
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-18

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
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-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-18

+ Details

Income Taxes - Provision for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Current:
State	$ 0	$ 0
Total current provision	0	0
Deferred:
Federal	(8,300)	19,054
State	(789)	4,902
Total deferred (benefit) expense	(9,089)	23,956
Valuation allowance	9,089	(23,956)
Provision for income taxes	$ 0	$ 0

- Definition

Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

+ References + Details

Income Taxes (Tables)

12 Months Ended

Dec. 31, 2023

Income Tax Disclosure [Abstract]

Provision for Income Taxes Based on Losses from Continuing Operations

The provision for income taxes based on losses from continuing operations consists of the following at December 31:


	Years ended December 31,
(in thousands)	2023		2022
Current:

State	$	—	$	—
Total current provision	—		—
Deferred:
Federal	(8,300)		19,054
State	(789)		4,902

Total deferred (benefit) expense	(9,089)		23,956
Valuation allowance	9,089		(23,956)
Total income tax provision	$	—	$	—

Schedule of Significant Components of the Company’s Taxes and the Rates

Significant components of the Company’s taxes and the rates as of December 31 are shown below:


	Years ended December 31,
(in thousands, except percentages)	2023				2022
Tax computed at the federal statutory rate	$	(8,703)	21	%	$	(8,128)	21	%
State tax, net of federal tax benefit	(645)		2	%	(518)		1	%

Permanent items	(2)		—	%	32,369		(84)	%
Stock based compensation	902		(2)	%	553		(1)	%
Research and development credits	(515)		1	%	(319)		1	%

Other	(126)		—	%	(1)		—	%
Valuation allowance increase (decrease)	9,089		(22)	%	(23,956)		62	%

Provision for income taxes	$	—	—	%	$	—	—	%

Schedule of Significant Components of the Company’s Deferred Tax Assets

Significant components of the Company’s deferred tax assets and liabilities from federal and state income taxes as of December 31 are shown below (in thousands):


	Years ended December 31,
(in thousands)	2023		2022
Deferred tax assets:
Tax loss carryforwards	$	23,441	$	20,289
Research and development credits and other tax credits	3,611		2,743
Stock-based compensation	1,407		1,317
Capitalized research and development	9,687		4,794
Other	1,400		1,431
Total deferred tax assets	39,546		30,574
Deferred tax liabilities:
Operating lease right-of-use assets	(375)		(492)

Total deferred tax liabilities	(375)		(492)
Net deferred tax assets before valuation allowance	39,171		30,082
Valuation allowance	(39,171)		(30,082)
Net deferred tax asset	$	—	$	—

Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Preferred Stock	Common Stock	Additional Paid-In Capital	Service Receivable	Accumulated other comprehensive loss	Accumulated Deficit
Balance (in shares) at Dec. 31, 2021		716	41,964
Balance at Dec. 31, 2021	$ 140,417	$ 1	$ 4	$ 400,503	$ (139)	$ (142)	$ (259,810)
Increase (Decrease) in Stockholders' Equity
Stock-based compensation	4,256			4,256
Issuance of common stock upon exercise of warrants (in shares)			29
Issuance of common stock upon exercise of warrants	75			75
Issuance of common stock upon conversion of Convertible Preferred Stock (in shares)		(655)	2,684
Issuance of common stock upon conversion of Series E Convertible Preferred Stock	(1)	$ (1)
Unrealized gain (loss) on securities available-for-sale	(253)					(253)
Release of clinical trial funding commitment	139				139
Cumulative preferred stock dividend adjustment	414						414
Net loss	(38,704)						(38,704)
Balance (in shares) at Dec. 31, 2022		61	44,677
Balance at Dec. 31, 2022	106,343	$ 0	$ 4	404,834	0	(395)	(298,100)
Increase (Decrease) in Stockholders' Equity
Stock-based compensation	4,509			4,509
Unrealized gain (loss) on securities available-for-sale	328					328
Net loss	(41,441)						(41,441)
Balance (in shares) at Dec. 31, 2023		61	44,677
Balance at Dec. 31, 2023	$ 69,739	$ 0	$ 4	$ 409,343	$ 0	$ (67)	$ (339,541)

Leases

12 Months Ended

Dec. 31, 2023

Leases [Abstract]

Leases

As a lessee, the Company’s current lease includes its master facility lease which is considered an operating lease.

Master Facility Lease

The Company currently leases office and lab space in San Diego that expires on February 28, 2027. The lease currently requires monthly payments of approximately $63,000 per month with 3% annual escalation.

The components of lease expense were as follows:


(in thousands)	Twelve Months Ended December 31, 2023		Twelve Months Ended December 31, 2022
Operating lease cost	$	714	$	754

Net operating lease cost	$	714	$	754

Supplemental balance sheet information related to leases was as follows:


(in thousands)	As of December 31, 2023			As of December 31, 2022
Operating lease ROU assets	$	1,708		$	2,251

Current operating lease liabilities	$	691		$	675
Non-current operating lease liabilities	1,458			2,040
Total operating lease liabilities	$	2,149		$	2,715

Weighted-average remaining lease term–operating leases	3.2 years			4.2 years
Weighted-average discount rate–operating leases	7		%	7		%

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


(in thousands)	Twelve Months Ended December 31, 2023		Twelve Months Ended December 31, 2022
Cash paid for amounts included in the measurement of lease liabilities:
Cash paid included in operating cash flows	$	737	$	612

Total remaining annual commitments under non-cancelable operating lease agreements as of December 31, 2023, are summarized are as follows:


(in thousands)
Year Ending December 31,	Operating Leases




2024	$	691
2025	775
2026	796
2027	136
Thereafter	—
Total future minimum lease payments	$	2,398
Less imputed interest	(249)
Total	$	2,149

Leases

As a lessee, the Company’s current lease includes its master facility lease which is considered an operating lease.

Master Facility Lease

The components of lease expense were as follows:


(in thousands)	Twelve Months Ended December 31, 2023		Twelve Months Ended December 31, 2022
Operating lease cost	$	714	$	754

Net operating lease cost	$	714	$	754

Supplemental balance sheet information related to leases was as follows:


(in thousands)	As of December 31, 2023			As of December 31, 2022
Operating lease ROU assets	$	1,708		$	2,251

Current operating lease liabilities	$	691		$	675
Non-current operating lease liabilities	1,458			2,040
Total operating lease liabilities	$	2,149		$	2,715

Weighted-average remaining lease term–operating leases	3.2 years			4.2 years
Weighted-average discount rate–operating leases	7		%	7		%

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


(in thousands)	Twelve Months Ended December 31, 2023		Twelve Months Ended December 31, 2022
Cash paid for amounts included in the measurement of lease liabilities:
Cash paid included in operating cash flows	$	737	$	612

Total remaining annual commitments under non-cancelable operating lease agreements as of December 31, 2023, are summarized are as follows:


(in thousands)
Year Ending December 31,	Operating Leases




2024	$	691
2025	775
2026	796
2027	136
Thereafter	—
Total future minimum lease payments	$	2,398
Less imputed interest	(249)
Total	$	2,149

Fair Value Measurements (Tables)

12 Months Ended

Dec. 31, 2023

Fair Value Disclosures [Abstract]

Schedule of 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


	Fair Value Measurements at December 31, 2023
(in thousands)	Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Assets:
Money market fund	$	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


	Fair Value Measurements at December 31, 2022
(in thousands)	Quoted Prices in Active Markets for Identical Assets and Liabilities (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)		Total
Assets:
Money market fund	$	15,722	$	—	$	—	$	15,722

Total included in cash and cash equivalents	$	15,722	$	—	$	—	$	15,722

Available for sale investments:
Certificate of deposit	$	—	$	16,023	$	—	$	16,023
Corporate debt securities	—		49,535		—		49,535
Commercial paper	—		13,187		—		13,187

U.S. government agencies	—		2,288		—		2,288
U.S. treasury securities	7,887		—		—		7,887
Total available for sale investments	$	7,887	$	81,033	$	—	$	88,920

Total assets measured at fair value on a recurring basis	$	23,609	$	81,033	$	—	$	104,642

Stock-Based Compensation - Stock-Based Compensation (Details) - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	$ 4,509,000	$ 4,256,000
Research and development expenses
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	1,279,000	1,035,000
Selling, general and administrative expenses
Share-based Payment Arrangement, Expensed and Capitalized, Amount [Line Items]
Total stock-based compensation	$ 3,230,000	$ 3,221,000

Business Overview and Liquidity (Details) $ in Millions	Dec. 31, 2023 USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Cash, cash equivalents and short-term investments	$ 74.8

Basis of Presentation and Summary of Significant Accounting Policies (Policies)

12 Months Ended

Dec. 31, 2023

Accounting Policies [Abstract]

Segment Reporting

Use of Estimates

Accrued Clinical Trial Expenses

Cash and Cash Equivalents

Cash and cash equivalents

Investment Securities and Short-term investments

Investment Securities

Short-term investments

Concentration of Credit Risk

Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash, cash equivalents and short-term investments.

Revenues

Royalty and License Revenues

Payment terms and conditions vary by contracts, although terms generally include a requirement of payment within 30 to 45 days after invoice. Royalties are generally due quarterly or annually.

Derivative Financial Instruments—Warrants

fair value. The use of the Black-Scholes model classifies such warrants as Level 3 (See "Fair Value of Financial Instruments" below).

Stock-Based Compensation

Fair Value of Financial Instruments

•Level 1 — Quoted prices for identical instruments in active markets.

•Level 3 — Instruments where significant value drivers are unobservable to third parties.

Long-Lived Assets


			Estimated Useful Lives
Furniture and office equipment			3 to 5 years
Leasehold improvements			4 to 6 years
Laboratory equipment			5 years

Impairment Losses on Long-Lived Assets

Leases

Leases with an initial term of 12 months or less are not recorded on the Company's balance sheets. These short-term leases are expensed on a straight-line basis over the lease term.

Income Taxes

Contingencies

Research and Development

Net Loss Per Share

Recently Adopted Accounting Pronouncement and Recent Accounting Pronouncement Not Yet Adopted

Recently Adopted Accounting Pronouncement

Recent Accounting Pronouncement Not Yet Adopted

Stock-Based Compensation - Assumptions Using Black-Scholes for Estimated Fair Value of Stock Options (Details) - Options to purchase Common Stock	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Dividend yield	0.00%	0.00%
Expected volatility (weighted-average)	109.00%	106.00%
Expected term (in years)	5 years 2 months 12 days	6 years
Minimum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Risk-free interest rate (range)	3.56%	1.62%
Expected volatility (range)	105.00%	98.00%
Maximum
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Risk-free interest rate (range)	4.06%	3.75%
Expected volatility (range)	110.00%	110.00%

Derivative Financial Instruments - Warrants (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($) shares	Dec. 31, 2022 USD ($) $ / shares shares
Changes in the Company's derivative financial instruments liability balance
Balance of warrants outstanding at the beginning of the period (in shares)	4,360,968	4,490,159
Balance of warrants outstanding at the end of the period (in shares)	2,807,948	4,360,968
Warrants to purchase Common Stock
Range of assumptions used to determine the fair value of warrants
Estimated fair value of Trovagene common stock (in dollars per share) \| $ / shares		$ 1.40
Warrants to purchase Common Stock \| Black Scholes Option Pricing Method
Changes in the Company's derivative financial instruments liability balance
Balance of warrants outstanding at the beginning of the period (in shares)	64,496	64,496
Expiration of Derivative Financial Instruments (in shares)		(64,496)
Balance of warrants outstanding at the end of the period (in shares)	0	64,496
Balance of derivative financial instruments liability at the beginning of the period \| $	$ 0	$ 285
Change in fair value of derivative financial instruments—warrants during the year recognized as a loss in the statement of operations \| $	0	(285)
Expiration of Derivative Financial Instruments \| $		0
Balance of derivative financial instruments liability at the end of the period \| $	$ 0	$ 0
Expected term \| Warrants to purchase Common Stock
Range of assumptions used to determine the fair value of warrants
Expected warrant term		1 month 6 days
Risk-free interest rate \| Warrants to purchase Common Stock
Range of assumptions used to determine the fair value of warrants
Measurement input		0.0412
Expected volatility \| Warrants to purchase Common Stock
Range of assumptions used to determine the fair value of warrants
Measurement input		0.54
Dividend yield \| Warrants to purchase Common Stock
Range of assumptions used to determine the fair value of warrants
Measurement input		0

Basis of Presentation and Summary of Significant Accounting Policies - Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2023 USD ($) segment	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)
Derivative financial instruments
Number of operating segments \| segment	1
Accrued clinical trial expenses	$ 4,300
Payment terms	Payment terms and conditions vary by contracts, although terms generally include a requirement of payment within 30 to 45 days after invoice.
Warrants to purchase Common Stock \| Black Scholes Option Pricing Method
Derivative financial instruments
Derivative financial instruments—warrants	$ 0	$ 0	$ 285

Leases - Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Leases [Abstract]
Cash paid included in operating cash flows	$ 737	$ 612

Basis of Presentation and Summary of Significant Accounting Policies - Long-Lived Assets (Details)	Dec. 31, 2023
Furniture and office equipment \| Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives	3 years
Furniture and office equipment \| Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives	5 years
Leasehold improvements \| Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives	4 years
Leasehold improvements \| Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives	6 years
Laboratory equipment
Property, Plant and Equipment [Line Items]
Estimated useful lives	5 years

Stock-Based Compensation - Summary of Stock Options Activity (Details) - Options to purchase Common Stock - USD ($)	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Number of Options
Beginning balance (in shares)	5,069,458
Granted (in shares)	2,138,624
Forfeited and expired (in shares)	(557,128)
Ending balance (in shares)	6,650,954	5,069,458
Vested and exercisable (in shares)	3,124,492
Vested and expected to vest (in shares)	6,462,464
Weighted-Average Exercise Price Per Share
Outstanding (in dollars per share)	$ 5.92
Granted (in dollars per share)	1.70
Forfeited and expired (in dollars per share)	9.43
Outstanding (in dollars per share)	4.27	$ 5.92
Vested and exercisable (in dollars per share)	5.66
Vested and expected to vest (in dollars per share)	$ 4.33
Intrinsic value, outstanding	$ 23,926	$ 19,322
Intrinsic value, vested and exercisable	22,456
Intrinsic value, vested and expected to vest	$ 23,853
Weighted average remaining contract term, outstanding	7 years 10 months 24 days	7 years 4 months 24 days
Weighted average remaining contractual term, exercisable	6 years 10 months 24 days
Weighted average remaining contractual term, vested and expected to vest	7 years 9 months 18 days

Leases - Supplemental Balance Sheet Information (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Leases [Abstract]
Operating lease right-of-use assets	$ 1,708	$ 2,251
Current operating lease liabilities	691	675
Non-current operating lease liabilities	1,458	2,040
Total operating lease liabilities	$ 2,149	$ 2,715
Weighted-average remaining lease term–operating leases	3 years 2 months 12 days	4 years 2 months 12 days
Weighted-average discount rate–operating leases	7.00%	7.00%