0000950170-24-123349 | 10-Q | XBRL Viewer

Investment Securities

9 Months Ended

Sep. 30, 2024

Investments, Debt and Equity Securities [Abstract]

5. Investment Securities

The Company’s investment policy defines allowable investment securities and establishes guidelines relating to credit quality, diversification, and maturities of its investments to preserve principal and maintain liquidity. The Company’s investment securities consisted of the following at September 30, 2024 and December 31, 2023 (in thousands):


		As of September 30, 2024
											Estimated
									Allowance		Fair
		Amortized		Unrealized		Unrealized			for Credit		Market
	Maturity	Cost		Gains		Losses			Losses		Value
Certificates of deposits	Within 1 year	$	4,889	$	20	$	(1	)	$	—	$	4,908
U.S. Treasury securities	Within 1 year		164,693		494		(4	)		—		165,183
U.S. Government agency securities	Within 1 year		10,000		4		(2	)		—		10,002
Certificates of deposits	1 year to 2 years		199		3		—			—		202
U.S. Treasury securities	1 year to 2 years		35,551		402		—			—		35,953
U.S. Government agency securities	1 year to 2 years		7,500		—		(2	)		—		7,498
Total		$	222,832	$	923	$	(9	)	$	—	$	223,746

		As of December 31, 2023
											Estimated
									Allowance		Fair
		Amortized		Unrealized		Unrealized			for Credit		Market
	Maturity	Cost		Gains		Losses			Losses		Value
Certificates of deposits	Within 1 year	$	10,488	$	2	$	(23	)	$	—	$	10,467
U.S. Treasury securities	Within 1 year		162,746		70		(349	)		—		162,467
U.S. Government agency securities	Within 1 year		12,499		—		(29	)		—		12,470
Certificates of deposits	1 year to 2 years		3,862		12		(5	)		—		3,869
U.S. Treasury securities	1 year to 2 years		58,441		412		(16	)		—		58,837
U.S. Government agency securities	1 year to 2 years		12,500		2		(14	)		—		12,488
Total		$	260,536	$	498	$	(436	)	$	—	$	260,598

The Company reviews its investments at each reporting date to identify and evaluate whether a decline in fair value below the amortized cost basis of available-for-sale securities is due to credit-related factors and determines if such unrealized losses are the result of credit losses that require impairment. Factors considered in determining whether an unrealized loss is the result of a credit loss or other factors include the extent to which the fair value is less than the cost basis, any changes to the rating of the security by a rating agency, the financial condition and near-term prospects of the issuer, any historical failure of the issuer to make scheduled interest or principal payments, any adverse legal or regulatory events affecting the issuer or issuer’s industry, any significant deterioration in economic condition and the Company’s intent and ability to hold the investment for a period of time sufficient to allow for any anticipated recovery in market value.

There were 12 and 71 securities in an unrealized loss position at September 30, 2024 and December 31, 2023, respectively. The Company determined that unrealized losses on its available-for-sale investment securities were primarily attributable to changes in interest rates. Each security remained at a high credit quality rating. Further, there had been no adverse conditions noted for any of the issuers and the Company does not intend to sell any of the securities prior to maturity. As such, an allowance for credit losses has not been recognized as of September 30, 2024 or December 31, 2023.

The following tables present available-for-sale investments that were in an unrealized loss position as of September 30, 2024 and December 31, 2023, aggregated by security type and length of time in a continuous unrealized loss position (in thousands):


	As of September 30, 2024
	Less than 12 Months					12 Months or Greater					Total
	Estimated					Estimated					Estimated
	Fair					Fair					Fair
	Market		Unrealized			Market		Unrealized			Market		Unrealized
	Value		Losses			Value		Losses			Value		Losses
Certificates of deposits	$	490	$	—		$	734	$	(1	)	$	1,224	$	(1	)
U.S. Treasury securities		—		—			7,493		(4	)		7,493		(4	)
U.S. Government agency securities		12,496		(4	)		—		—			12,496		(4	)
Total	$	12,986	$	(4	)	$	8,227	$	(5	)	$	21,213	$	(9	)

	As of December 31, 2023
	Less than 12 Months					12 Months or Greater					Total
	Estimated					Estimated					Estimated
	Fair					Fair					Fair
	Market		Unrealized			Market		Unrealized			Market		Unrealized
	Value		Losses			Value		Losses			Value		Losses
Certificates of deposits	$	8,514	$	(14	)	$	1,456	$	(14	)	$	9,970	$	(28	)
U.S. Treasury securities		44,346		(102	)		51,979		(263	)		96,325		(365	)
U.S. Government agency securities		12,484		(16	)		7,473		(27	)		19,957		(43	)
Total	$	65,344	$	(132	)	$	60,908	$	(304	)	$	126,252	$	(436	)

As of September 30, 2024, the Company held 21 domestic certificates of deposit with amortized costs below the Federal Deposit Insurance Corporation insured limit. Accrued interest receivable on available-for-sale investment securities, included in prepaid expenses and other current assets on the Company’s balance sheets, was $1.2 million and $1.4 million at September 30, 2024 and December 31, 2023, respectively.

Net Loss Per Share (Tables)

9 Months Ended

Sep. 30, 2024

Earnings Per Share [Abstract]

Schedule of Antidilutive Securities Excluded in Calculation of Diluted Net Loss Per Share

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


	September 30, 2024		September 30, 2023
Stock options		10,634,334		9,106,844
Shares subject to repurchase		—		1,705
Employee stock purchase plan		133,358		79,498
Total		10,767,692		9,188,047

Condensed Statements of Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Statement of Comprehensive Income [Abstract]
Net loss	$ (13,039)	$ (15,789)	$ (35,937)	$ (55,020)
Other comprehensive loss:
Unrealized (loss) gain on available-for-sale securities	1,131	717	852	2,073
Comprehensive loss	$ (11,908)	$ (15,072)	$ (35,085)	$ (52,947)

- Definition

Amount after tax of increase (decrease) in equity from transactions and other events and circumstances from net income and other comprehensive income, attributable to parent entity. Excludes changes in equity resulting from investments by owners and distributions to owners.

+ References + Details

- 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

Stock-Based Compensation

9 Months Ended

Sep. 30, 2024

Share-Based Payment Arrangement [Abstract]

Stock-Based Compensation

11. Stock-Based Compensation

Equity Incentive Award Plans

The number of shares of common stock available for issuance under the Company's 2021 Equity Incentive Plan will automatically increase on January 1 of each calendar year through January 1, 2031, in an amount equal to 5% of the total number of shares of the Company’s common stock on the last day of the calendar month before the date of each automatic increase, or a lesser number of shares determined by the Company’s board of directors. As of September 30, 2024, the total number of shares available for future issuance was 5,825,742.

The following table summarizes stock option activity for the nine months ended September 30, 2024:


	Options			Weighted-Average Exercise Price
Outstanding at December 31, 2023		8,561,753		$	8.67
Granted		2,618,950		$	2.61
Exercised		(28,088	)	$	0.95
Forfeited		(518,281	)	$	12.41
Balance at September 30, 2024		10,634,334		$	7.02

Stock-based compensation expense has been reported in the Company's condensed statements of operations as follows (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2024		2023		2024		2023
Research and development	$	1,524	$	1,666	$	4,679	$	4,767
General and administrative		1,594		1,553		4,922		5,597
Total	$	3,118	$	3,219	$	9,601	$	10,364

In August 2023, the Company granted two stock options, each to purchase up to 525,000 shares of the Company's common stock, which contained both time-based and performance-based conditions. Stock-based compensation expense for awards with performance conditions is recognized ratably over the expected performance period when the achievement of such performance conditions is determined to be probable. The Company assessed the probability of achieving the performance-based conditions and recorded approximately $0.1 million and $0.2 million in general and administrative stock-based compensation expense during the three and nine months ended September 30, 2024, respectfully.

2021 Employee Stock Purchase Plan

The number of shares of common stock available for issuance under the Company's ESPP will automatically increase on January 1 of each calendar year through January 1, 2031, in an amount equal to the lesser of (i) 1% of the total number of shares of the Company’s common stock on the last day of the calendar month before the date of each automatic increase and (ii) 1,200,000 shares; or a lesser number of shares determined by the Company’s board of directors. As of September 30, 2024, the Company had issued 252,127 shares of the Company's common stock under the ESPP and had 2,028,858 shares available for future issuance.

Investment Securities - Summary of Amortized Cost, Unrealized Gains and Losses, Allowances for Credit Losses and Fair Value of Available-for-Sale Investments Aggregated by Maturity and Security Type (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2024	Dec. 31, 2023
Schedule Of Available For Sale Securities [Line Items]
Debt securities, Amortized Cost	$ 222,832	$ 260,536
Debt securities, Unrealized Gains	923	498
Debt securities, Unrealized Losses	(9)	(436)
Debt securities, Estimated Fair Value	$ 223,746	$ 260,598
Certificates of Deposit \| Within 1 Year
Schedule Of Available For Sale Securities [Line Items]
Debt securities, Maturity	Within 1 year	Within 1 year
Debt securities, Amortized Cost	$ 4,889	$ 10,488
Debt securities, Unrealized Gains	20	2
Debt securities, Unrealized Losses	(1)	(23)
Debt securities, Estimated Fair Value	$ 4,908	$ 10,467
Certificates of Deposit \| 1 Year to 2 Years
Schedule Of Available For Sale Securities [Line Items]
Debt securities, Maturity	1 year to 2 years	1 year to 2 years
Debt securities, Amortized Cost	$ 199	$ 3,862
Debt securities, Unrealized Gains	3	12
Debt securities, Unrealized Losses		(5)
Debt securities, Estimated Fair Value	$ 202	$ 3,869
U.S. Treasury Securities \| Within 1 Year
Schedule Of Available For Sale Securities [Line Items]
Debt securities, Maturity	Within 1 year	Within 1 year
Debt securities, Amortized Cost	$ 164,693	$ 162,746
Debt securities, Unrealized Gains	494	70
Debt securities, Unrealized Losses	(4)	(349)
Debt securities, Estimated Fair Value	$ 165,183	$ 162,467
U.S. Treasury Securities \| 1 Year to 2 Years
Schedule Of Available For Sale Securities [Line Items]
Debt securities, Maturity	1 year to 2 years	1 year to 2 years
Debt securities, Amortized Cost	$ 35,551	$ 58,441
Debt securities, Unrealized Gains	402	412
Debt securities, Unrealized Losses		(16)
Debt securities, Estimated Fair Value	$ 35,953	$ 58,837
U.S. Government agency securities \| Within 1 Year
Schedule Of Available For Sale Securities [Line Items]
Debt securities, Maturity	Within 1 year	Within 1 year
Debt securities, Amortized Cost	$ 10,000	$ 12,499
Debt securities, Unrealized Gains	4
Debt securities, Unrealized Losses	(2)	(29)
Debt securities, Estimated Fair Value	$ 10,002	$ 12,470
U.S. Government agency securities \| 1 Year to 2 Years
Schedule Of Available For Sale Securities [Line Items]
Debt securities, Maturity	1 year to 2 years	1 year to 2 years
Debt securities, Amortized Cost	$ 7,500	$ 12,500
Debt securities, Unrealized Gains		2
Debt securities, Unrealized Losses	(2)	(14)
Debt securities, Estimated Fair Value	$ 7,498	$ 12,488

Commitments and Contingencies

9 Months Ended

Sep. 30, 2024

Commitments and Contingencies Disclosure [Abstract]

Commitments and Contingencies

8. Commitments and Contingencies

Contingencies

From time to time, the Company may become subject to claims or suits arising in the ordinary course of business. The Company accrues a liability for such matters when it is probable that the future expenditures will be made and such expenditures can be reasonably estimated. The Company had no such contingent liabilities as of September 30, 2024 or December 31, 2023.

Leases - Summary of Maturities of Operating Lease Liabilities (Details) $ in Thousands	Sep. 30, 2024 USD ($)
Lessee, Operating Lease, Liability, to be Paid, Fiscal Year Maturity [Abstract]
2024 (remaining three months)	$ 233
2025	945
2026	973
2027	663
Total future minimum lease payments	2,814
Less: Present value adjustment	(292)
Operating lease liabilities	$ 2,522

Fair Value Measurements

9 Months Ended

Sep. 30, 2024

Fair Value Disclosures [Abstract]

Fair Value Measurements

4. Fair Value Measurements

Accounting guidance defines fair value, establishes a consistent framework for measuring fair value and expands disclosure for each major asset and liability category measured at fair value on either a recurring or non-recurring basis. Fair value is defined as an exit price, representing the amount that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants. As such, fair value is a market-based measurement that should be determined based on assumptions that market participants would use in pricing an asset or liability. As a basis for considering such assumptions, the accounting guidance establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value as follows:

Level 1: Observable inputs such as quoted prices in active markets.

Level 2: Inputs, other than the quoted prices in active markets that are observable either directly or indirectly.

Level 3: Unobservable inputs in which there is little or no market data, which require the reporting entity to develop its own assumptions.

The following table summarizes the Company’s financial instruments measured at fair value on a recurring basis at September 30, 2024 and December 31, 2023 (in thousands):


	Fair Value Measurement at End of Period Using:
			Quoted Prices
			In Active
			Markets		Significant
			For		Other		Significant
			Identical		Observable		Unobservable
			Assets		Inputs		Inputs
	Total		(Level 1)		(Level 2)		(Level 3)
As of September 30, 2024:
Assets:
Money market funds(1)	$	29,363	$	29,363	$	—	$	—
Certificates of deposit		5,110		5,110		—		—
U.S. Treasury securities		201,136		201,136		—		—
U.S. Government agency securities		17,500		—		17,500		—
Total	$	253,109	$	235,609	$	17,500	$	—
As of December 31, 2023:
Assets:
Money market funds(1)	$	19,619	$	19,619	$	—	$	—
Certificates of deposit		14,336		14,336		—		—
U.S. Treasury securities		221,304		221,304		—		—
U.S. Government agency securities		24,958		—		24,958		—
Total	$	280,217	$	255,259	$	24,958	$	—

(1)

Included in cash and cash equivalents on the accompanying balance sheets.

Interest bearing money market accounts and certificates of deposit are valued at amortized cost, which approximates fair value. The carrying value of the Company’s cash, accounts payable and accrued liabilities are considered to be representative of their respective fair values due to the short-term nature of those instruments. The Company’s investment securities, which may include money market accounts, money market funds, certificates of deposits, U.S. Treasury securities, and high quality, marketable debt instruments of corporations and government sponsored enterprises, are measured at fair value in accordance with the fair value hierarchy. The Company obtains the fair value of its available-for-sale debt securities from a professional pricing service. Level II securities are valued using quoted market prices for similar instruments, non-binding market prices that are corroborated by observable market data and include our investments in marketable debt instruments of government sponsored enterprises. None of the Company’s non-financial assets or liabilities are recorded at fair value on a non-recurring basis and no transfers between levels have occurred during the periods presented.

- 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

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 107
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482078/820-10-55-107

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 55
-Paragraph 100
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482078/820-10-55-100

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(3)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
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-Paragraph 6A
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-6A

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2E
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2E

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
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-Name Accounting Standards Codification
-Section 50
-Paragraph 6A
-Subparagraph (h)
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-URI https://asc.fasb.org/1943274/2147482106/820-10-50-6A

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6A
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-6A

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6A
-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-6A

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6A
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-6A

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 940
-SubTopic 820
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478119/940-820-50-1

+ Details

Related Party Transactions (Tables)

9 Months Ended

Sep. 30, 2024

Lease Agreement

Summary of Rent and Related Operating Expenses Recognized under Various Agreements

Rent, and related operating expenses recognized by the Company under the Lease and Lease Amendment during the periods presented were as follows (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2024		2023		2024		2023
Research and development	$	213	$	202	$	638	$	629
General and administrative		74		72		225		222
Total expenses	$	287	$	274	$	863	$	851

Consulting Agreements

Summary of Rent and Related Operating Expenses Recognized under Various Agreements

Expenses recognized by the Company under the 2020 Consulting Agreement during the periods presented were as follows (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2024		2023		2024		2023
General and administrative	$	60	$	60	$	180	$	180
Total expenses	$	60	$	60	$	180	$	180

Research Consulting Agreements

Summary of Rent and Related Operating Expenses Recognized under Various Agreements

Expenses recognized by the Company under the Research Consulting Agreement during the periods presented were as follows (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2024		2023		2024		2023
Research and development	$	11	$	45	$	32	$	135
Total expenses	$	11	$	45	$	32	$	135

Balance Sheet Details (Tables)

9 Months Ended

Sep. 30, 2024

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Summary of Prepaid Expenses and Other Current Assets

Prepaid expenses and other current assets consisted of the following (in thousands):


	September 30, 2024		December 31, 2023
Prepaid expenses	$	1,989	$	1,354
Interest receivable		1,179		1,432
Total	$	3,168	$	2,786

Summary of Property and Equipment

Property and equipment consisted of the following (in thousands):


	September 30, 2024			December 31, 2023
Laboratory equipment	$	2,291		$	1,976
Computer equipment and software		102			102
Furniture and fixtures		521			521
Leasehold improvements		151			151
		3,065			2,750
Less accumulated depreciation		(1,506	)		(1,059	)
Total	$	1,559		$	1,691

Summary of Accrued Expenses and Current Liabilities

Accrued expenses and current liabilities consisted of the following (in thousands):


	September 30, 2024		December 31, 2023
Accrued personnel costs	$	2,989	$	4,034
Accrued research and development costs		1,616		2,350
Current portion of operating lease liability, net, related party		778		716
Accrued other		579		582
Total	$	5,962	$	7,682

Pay vs Performance Disclosure - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
Pay vs Performance Disclosure - USD ($) $ in Thousands	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Pay vs Performance Disclosure
Net Income (Loss)	$ (13,039)	$ (15,789)	$ (35,937)	$ (55,020)

- Definition

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

+ References

+ Details

Stock-Based Compensation - Additional Information (Details) $ in Thousands	1 Months Ended	3 Months Ended		9 Months Ended
	Aug. 31, 2023 StockOption shares	Sep. 30, 2024 USD ($) shares	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($) shares	Sep. 30, 2023 USD ($)	Mar. 25, 2021 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Type of stock options granted to purchase common stock \| StockOption	2
Stock-based compensation expense \| $		$ 3,118	$ 3,219	$ 9,601	$ 10,364
General and Administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense \| $		1,594	$ 1,553	4,922	$ 5,597
August 2023 Stock Options \| General and Administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense \| $		$ 100		$ 200
Stock Option One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock options granted to each type of incentive plans to purchase common stock	525,000
Stock Option Two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock options granted to each type of incentive plans to purchase common stock	525,000
2021 Equity Incentive Award Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock issuance, description and terms				The number of shares of common stock available for issuance under the Company's 2021 Equity Incentive Plan will automatically increase on January 1 of each calendar year through January 1, 2031, in an amount equal to 5% of the total number of shares of the Company’s common stock on the last day of the calendar month before the date of each automatic increase, or a lesser number of shares determined by the Company’s board of directors.
Common stock reserved for issuance		5,825,742		5,825,742
2021 Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock issuance, description and terms				The number of shares of common stock available for issuance under the Company's ESPP will automatically increase on January 1 of each calendar year through January 1, 2031, in an amount equal to the lesser of (i) 1% of the total number of shares of the Company’s common stock on the last day of the calendar month before the date of each automatic increase and (ii) 1,200,000 shares; or a lesser number of shares determined by the Company’s board of directors.
Common stock reserved for issuance		2,028,858		2,028,858
Common stock remained available for issuance						1,200,000
Issuance of common stock under employee stock purchase plan, Shares				252,127

Investment Securities - Additional Information (Details) $ in Millions	Sep. 30, 2024 USD ($) Security	Dec. 31, 2023 USD ($) Security
Investments, Debt and Equity Securities [Abstract]
Number of available-for-sale investment securities in continuous unrealized loss position	12	71
Number of domestic certificates of deposit held	21
Accrued interest receivable on available-for-sale investment securities \| $	$ 1.2	$ 1.4

License Agreements - Additional Information (Details) - License Agreement	3 Months Ended	9 Months Ended
	Sep. 30, 2024 USD ($)	Sep. 30, 2024 USD ($)
Schedule Of License Agreement [Line Items]
Milestone payment		$ 100,000
Written notice period to terminated agreement		60 days
Written notice period to terminated license agreement in event of breach of contract		30 days
Uncured period of agreement in event of breach of agreement notice		60 days
Termination period Description		WARF may terminate the License Agreement with 90 days written notice if first commercial sale does not occur before December 31, 2031. Unless terminated earlier by the parties, the term of the License Agreement will continue until the last licensed patent expires in all countries.
Maximum
Schedule Of License Agreement [Line Items]
Potential milestone payments		$ 800,000
Investigation New Drug (IND)
Schedule Of License Agreement [Line Items]
Written notice period for termination of agreement		90 days
Investigation New Drug (IND) \| Maximum
Schedule Of License Agreement [Line Items]
Expected milestone payment on achieving certain regulatory and commercial milestones	$ 17,500,000	$ 17,500,000
Investigation New Drug (IND) \| Minimum
Schedule Of License Agreement [Line Items]
Expected royalty payments upon first commercial product sale	100,000	100,000
Research and Development
Schedule Of License Agreement [Line Items]
Upfront payment upon execution of agreement		300,000
Upfront fee	$ 0	$ 200,000

Leases (Tables)

9 Months Ended

Sep. 30, 2024

Leases [Abstract]

Summary of Maturities of Operating Lease Liabilities

Maturities of operating lease liabilities as of September 30, 2024 are as follows (in thousands):


2024 (remaining three months)	$	233
2025		945
2026		973
2027		663
Thereafter		—
Total future minimum lease payments		2,814
Less: Present value adjustment		(292	)
Operating lease liabilities	$	2,522

Basis of Presentation and Summary of Significant Accounting Policies

9 Months Ended

Sep. 30, 2024

Accounting Policies [Abstract]

Basis of Presentation and Summary of Significant Accounting Policies

2. Basis of Presentation and Summary of Significant Accounting Policies

Basis of Presentation and Use of Estimates

The accompanying unaudited interim condensed financial statements have been prepared in accordance with U.S. generally accepted accounting principles and following the requirements of the United States Securities and Exchange Commission (“SEC”) for interim reporting. The Company's financial statements include all adjustments, consisting of only normal recurring adjustments, which in the opinion of management are necessary to present fairly the Company’s financial position as of the reporting date and results of operations and cash flows for the periods presented.

The preparation of the Company’s financial statements requires it to make estimates and assumptions that impact the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent assets and liabilities in the Company’s financial statements and accompanying notes. The most significant estimates in the Company’s financial statements relate to accruals for research and development expenses. These estimates and assumptions are based on current facts, historical experience and various other factors believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities and the recording of expenses that are not readily apparent from other sources. Actual results may differ materially and adversely from these estimates.

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 in making decisions regarding resource allocation and assessing performance. The Company manages its operations as a single reportable segment for the purposes of assessing performance and making operating decisions.

Recent Accounting Pronouncements

In November 2023, the Financial Accounting Standards Board (FASB) issued Accounting Standard Update (ASU) No. 2023-07, Accounting Standards Codification (ASC) Topic 280, Segment Reporting: Improvements to Reportable Segment Disclosures, which expands annual and interim disclosure requirements for reportable segments, primarily through enhanced disclosures about significant segment expenses. The ASU also requires public entities with a single reportable segment to provide all segment disclosures under ASC 280, including the new disclosures under the ASU. Annual disclosures are required for fiscal years beginning after December 15, 2023 and for interim disclosures within fiscal years beginning after December 15, 2024. Retrospective application is required and early adoption is permitted. The Company is currently evaluating the impact that the updated standard will have on its financial statement disclosures.

In December 2023, the FASB issued ASU 2023-09, ASC Topic 740, Income Taxes: Improvements to Income Tax Disclosures, which 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 fiscal years beginning after December 15, 2024, with early adoption permitted. The Company is continuing to evaluate the impact of adopting this new guidance but does not expect it to have a material impact on the Company’s financial position or results of operations.

Organization - Additional Information (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Subsidiary, Sale of Stock [Line Items]
Accumulated deficit	$ (213,563)	$ (177,626)
Cash, cash equivalents and investment securities	$ 254,100

- Definition

Amount of accumulated undistributed earnings (deficit).

+ References + Details

Related Party Transactions - Summary of Rent and Related Operating Expenses Recognized under Various Agreements (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Related Party Transaction [Line Items]
Research and development	$ 11,876	$ 13,257	$ 32,193	$ 46,051
General and administrative	4,370	5,565	13,496	17,018
Lease Agreement
Related Party Transaction [Line Items]
Research and development	213	202	638	629
General and administrative	74	72	225	222
Total expenses	287	274	863	851
Research Consulting Agreements
Related Party Transaction [Line Items]
Research and development	11	45	32	135
Total expenses	11	45	32	135
Marlinspike Group, LLC \| Consulting Agreements
Related Party Transaction [Line Items]
General and administrative	60	60	180	180
Total expenses	$ 60	$ 60	$ 180	$ 180

Related Party Transactions

9 Months Ended

Sep. 30, 2024

Related Party Transactions

12. Related Party Transactions

Lease Agreement

In February 2021, the Company entered into the Lease with Crossing Holdings, LLC to rent laboratory and office space. In March 2022, the Company entered into the Lease Amendment with Crossing Holdings, LLC amending the Lease for additional office space in the same building. Dr. Pratik Shah and entities that he controls are the sole members of Crossing Holdings, LLC.

Rent, and related operating expenses recognized by the Company under the Lease and Lease Amendment during the periods presented were as follows (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2024		2023		2024		2023
Research and development	$	213	$	202	$	638	$	629
General and administrative		74		72		225		222
Total expenses	$	287	$	274	$	863	$	851

Consulting Agreements

In January 2019, the Company entered into an agreement with the Marlinspike Group, LLC (“Marlinspike Group”) for research support, management, and business consulting services (the “2019 Consulting Agreement”). Further, Marlinspike Group provides the use of approximately 2,120 square feet of its office space in Carlsbad, California to the Company on an as-available basis from time to time pursuant to the agreement. The Company’s Chief Executive Officer and Chairperson of its board of directors is an executive officer of Marlinspike Group.

The term of the 2019 Consulting Agreement was for a one-year period, subject to automatic one-month renewals unless terminated upon 14 days’ written notice. In March 2020, the Consulting Agreement was terminated and replaced with an amended consulting agreement (the “2020 Consulting Agreement”), which provides for similar services and use of office space for a monthly fee of $20,000. Pursuant to the terms of the 2020 Consulting Agreement, it shall remain in effect until otherwise terminated. Termination may occur at any time upon mutual agreement or unilaterally upon 30 days’ written notice. If the Company unilaterally terminates the 2020 Consulting Agreement for any reason other than cause, it would be subject to a $240,000 termination fee. The Company cannot determine when, or if, such a termination will occur and hence has not recorded a liability for the fee.

Expenses recognized by the Company under the 2020 Consulting Agreement during the periods presented were as follows (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2024		2023		2024		2023
General and administrative	$	60	$	60	$	180	$	180
Total expenses	$	60	$	60	$	180	$	180

In December 2017, the Company entered into a consulting agreement with Aseem Z. Ansari, Ph.D., a co-founder, to provide consulting services and advise on certain research and development activities (the “Research Consulting Agreement”). Pursuant to the Research Consulting Agreement, as amended, Dr. Ansari performed these services for a monthly fee of $15,000. In November 2023, the Company further amended the Research Consulting Agreement to discontinue the monthly fee, effective October 1, 2023, and provide for an option grant to Dr. Ansari to purchase 100,000 shares of the Company's common stock. The option has a grant date fair value of $1.72 per share and is being expensed to research and development over a four-year vesting period. The Company recorded approximately $11,000 and $32,000 in related stock-based compensation expense during the three and nine months ended September 30, 2024, respectively.

Expenses recognized by the Company under the Research Consulting Agreement during the periods presented were as follows (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2024		2023		2024		2023
Research and development	$	11	$	45	$	32	$	135
Total expenses	$	11	$	45	$	32	$	135

- Definition

The entire disclosure for related party transactions. Examples of related party transactions include transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners; and (d) affiliates.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480990/946-20-50-2

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480990/946-20-50-5

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480990/946-20-50-6

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
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-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477968/946-235-50-2

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
-Section 50
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-Subparagraph (e)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477968/946-235-50-2

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 850
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-Paragraph 1
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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-Name Accounting Standards Codification
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
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Reference 10: http://www.xbrl.org/2003/role/disclosureRef
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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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Reference 13: http://www.xbrl.org/2003/role/disclosureRef
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-Section 50
-Paragraph 1
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147483326/850-10-50-1

+ Details

Condensed Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Accrued expenses and other current liabilities, related party amounts	$ 778	$ 716
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	200,000,000	200,000,000
Common stock, shares issued	56,621,037	56,473,598
Common stock, shares outstanding	56,621,037	56,473,598

Condensed Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Operating expenses:
Research and development (including related party amounts of $224, $247, $670 and $764, respectively)	$ 11,876	$ 13,257	$ 32,193	$ 46,051
General and administrative (including related party amounts of $134, $132, $405 and $402, respectively)	4,370	5,565	13,496	17,018
Total operating expenses	16,246	18,822	45,689	63,069
Loss from operations	(16,246)	(18,822)	(45,689)	(63,069)
Other income, net	3,207	3,033	9,752	8,049
Net loss	$ (13,039)	$ (15,789)	$ (35,937)	$ (55,020)
Net loss per share, basic	$ (0.23)	$ (0.28)	$ (0.64)	$ (0.98)
Net loss per share, diluted	$ (0.23)	$ (0.28)	$ (0.64)	$ (0.98)
Weighted-average shares of common stock outstanding, basic	56,620,731	55,988,691	56,555,312	55,948,867
Weighted-average shares of common stock outstanding, diluted	56,620,731	55,988,691	56,555,312	55,948,867

Related Party Transactions - Additional Information (Details)	1 Months Ended				3 Months Ended		9 Months Ended
	Nov. 30, 2023 $ / shares shares	Mar. 31, 2020 USD ($)	Jan. 31, 2019 ft²	Dec. 31, 2017 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)
Related Party Transaction [Line Items]
Stock-based compensation expense					$ 3,118,000	$ 3,219,000	$ 9,601,000	$ 10,364,000
Marlinspike Group, LLC \| 2020 Consulting Agreement
Related Party Transaction [Line Items]
Monthly fee for consultancy services		$ 20,000
Termination fee		$ 240,000
Marlinspike Group, LLC \| Carlsbad, California \| 2019 Consulting Agreement
Related Party Transaction [Line Items]
Area of office space \| ft²			2,120
Aseem Z. Ansari, Ph.D. \| Consulting Agreements
Related Party Transaction [Line Items]
Monthly fee for services				$ 15,000
Option to purchase \| shares	100,000
Grant date fair value \| $ / shares	$ 1.72
Stock-based compensation expense					$ 11,000		$ 32,000

Net Loss Per Share - Schedule of Antidilutive Securities Excluded in Calculation of Diluted Net Loss Per Share (Details) - shares	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of diluted net loss per share	10,767,692	9,188,047
Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of diluted net loss per share	10,634,334	9,106,844
Shares Subject to Repurchase
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of diluted net loss per share	0	1,705
Employee Stock Purchase Plan
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of diluted net loss per share	133,358	79,498

Balance Sheet Details - Summary of Prepaid Expenses and Other Current Assets (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Prepaid Expense and Other Assets, Current [Abstract]
Prepaid expenses	$ 1,989	$ 1,354
Interest receivable	1,179	1,432
Total	$ 3,168	$ 2,786

Document and Entity Information - shares	9 Months Ended
Document and Entity Information - shares	Sep. 30, 2024	Nov. 04, 2024
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2024
Document Fiscal Year Focus	2024
Document Fiscal Period Focus	Q3
Trading Symbol	DSGN
Entity Registrant Name	Design Therapeutics, Inc.
Entity Central Index Key	0001807120
Current Fiscal Year End Date	--12-31
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Shell Company	false
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	true
Entity Common Stock, Shares Outstanding		56,621,037
Title of 12(b) Security	Common Stock, $0.0001 par value per share
Entity File Number	001-40288
Security Exchange Name	NASDAQ
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	82-3929248
Entity Address, Address Line One	6005 Hidden Valley Road
Entity Address, Address Line Two	Suite 110
Entity Address, City or Town	Carlsbad
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	92011
City Area Code	858
Local Phone Number	293-4900
Document Transition Report	false
Document Quarterly Report	true

Stockholders' Deficit

9 Months Ended

Sep. 30, 2024

Equity [Abstract]

Stockholders' Deficit

10. Stockholders’ Deficit

Shelf Registration Statement

In April 2022, the Company filed a shelf registration statement on Form S-3 (the “2022 Shelf Registration Statement”), which became effective in May 2022. The 2022 Shelf Registration Statement permits: (i) the offering, issuance and sale by the Company of

up to a maximum aggregate offering price of $300.0 million of common stock, preferred stock, debt securities and warrants in one or more offerings and in any combination; and (ii) the offering, issuance and sale by the Company of up to a maximum aggregate offering price of $100.0 million of our common stock that may be issued and sold under an “at-the-market” sales agreement (the “ATM Program”). The $100.0 million of common stock that may be issued and sold under the ATM Program is included in the $300.0 million of securities that may be issued and sold under the 2022 Shelf Registration Statement. As of September 30, 2024, the Company has not sold any shares of its common stock under the ATM Program.

- Definition

The entire disclosure for equity.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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+ Details

Balance Sheet Details

9 Months Ended

Sep. 30, 2024

Balance Sheet Component [Abstract]

Balance Sheet Details

6. Balance Sheet Details

Prepaid expenses and other current assets consisted of the following (in thousands):


	September 30, 2024		December 31, 2023
Prepaid expenses	$	1,989	$	1,354
Interest receivable		1,179		1,432
Total	$	3,168	$	2,786

Property and equipment consisted of the following (in thousands):


	September 30, 2024			December 31, 2023
Laboratory equipment	$	2,291		$	1,976
Computer equipment and software		102			102
Furniture and fixtures		521			521
Leasehold improvements		151			151
		3,065			2,750
Less accumulated depreciation		(1,506	)		(1,059	)
Total	$	1,559		$	1,691

Accrued expenses and current liabilities consisted of the following (in thousands):


	September 30, 2024		December 31, 2023
Accrued personnel costs	$	2,989	$	4,034
Accrued research and development costs		1,616		2,350
Current portion of operating lease liability, net, related party		778		716
Accrued other		579		582
Total	$	5,962	$	7,682

Basis of Presentation and Summary of Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2024
Accounting Policies [Abstract]
Basis of Presentation and Use of Estimates	Basis of Presentation and Use of Estimates The accompanying unaudited interim condensed financial statements have been prepared in accordance with U.S. generally accepted accounting principles and following the requirements of the United States Securities and Exchange Commission (“SEC”) for interim reporting. The Company's financial statements include all adjustments, consisting of only normal recurring adjustments, which in the opinion of management are necessary to present fairly the Company’s financial position as of the reporting date and results of operations and cash flows for the periods presented. The preparation of the Company’s financial statements requires it to make estimates and assumptions that impact the reported amounts of assets, liabilities, revenues and expenses and the disclosure of contingent assets and liabilities in the Company’s financial statements and accompanying notes. The most significant estimates in the Company’s financial statements relate to accruals for research and development expenses. These estimates and assumptions are based on current facts, historical experience and various other factors believed to be reasonable under the circumstances, the results of which form the basis for making judgments about the carrying values of assets and liabilities and the recording of expenses that are not readily apparent from other sources. Actual results may differ materially and adversely from these estimates.
Segment Reporting	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 in making decisions regarding resource allocation and assessing performance. The Company manages its operations as a single reportable segment for the purposes of assessing performance and making operating decisions.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In November 2023, the Financial Accounting Standards Board (FASB) issued Accounting Standard Update (ASU) No. 2023-07, Accounting Standards Codification (ASC) Topic 280, Segment Reporting: Improvements to Reportable Segment Disclosures, which expands annual and interim disclosure requirements for reportable segments, primarily through enhanced disclosures about significant segment expenses. The ASU also requires public entities with a single reportable segment to provide all segment disclosures under ASC 280, including the new disclosures under the ASU. Annual disclosures are required for fiscal years beginning after December 15, 2023 and for interim disclosures within fiscal years beginning after December 15, 2024. Retrospective application is required and early adoption is permitted. The Company is currently evaluating the impact that the updated standard will have on its financial statement disclosures. In December 2023, the FASB issued ASU 2023-09, ASC Topic 740, Income Taxes: Improvements to Income Tax Disclosures, which 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 fiscal years beginning after December 15, 2024, with early adoption permitted. The Company is continuing to evaluate the impact of adopting this new guidance but does not expect it to have a material impact on the Company’s financial position or results of operations.

- Definition

Disclosure of accounting policy for segment reporting.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
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-Name Accounting Standards Codification
-Section 50
-Paragraph 41
-Subparagraph (a)
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
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-URI https://asc.fasb.org/1943274/2147482810/280-10-50-29

+ Details

Condensed Statements of Stockholders' Equity (Unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive (Loss) Income	Accumulated Deficit
Beginning Balance at Dec. 31, 2022	$ 327,310	$ 6	$ 441,424	$ (3,356)	$ (110,764)
Beginning Balance, Shares at Dec. 31, 2022		55,895,596
Exercises of stock options and vesting of restricted stock	24		24
Exercises of stock options and vesting of restricted stock, Shares		66,844
Issuance of common stock under employee stock purchase plan	206		206
Issuance of common stock under employee stock purchase plan, Shares		35,547
Stock-based compensation	10,364		10,364
Unrealized gain on investments	2,073			2,073
Net loss	(55,020)				(55,020)
Ending Balance at Sep. 30, 2023	284,957	$ 6	452,018	(1,283)	(165,784)
Ending Balance, Shares at Sep. 30, 2023		55,997,987
Beginning Balance at Jun. 30, 2023	296,795	$ 6	448,784	(2,000)	(149,995)
Beginning Balance, Shares at Jun. 30, 2023		55,979,199
Exercises of stock options and vesting of restricted stock	15		15
Exercises of stock options and vesting of restricted stock, Shares		18,788
Stock-based compensation	3,219		3,219
Unrealized gain on investments	717			717
Net loss	(15,789)				(15,789)
Ending Balance at Sep. 30, 2023	284,957	$ 6	452,018	(1,283)	(165,784)
Ending Balance, Shares at Sep. 30, 2023		55,997,987
Beginning Balance at Dec. 31, 2023	277,687	$ 6	455,245	62	(177,626)
Beginning Balance, Shares at Dec. 31, 2023		56,473,598
Exercises of stock options	$ 27		27
Exercises of stock options, Shares	28,088	28,088
Issuance of common stock under employee stock purchase plan	$ 223		223
Issuance of common stock under employee stock purchase plan, Shares		119,351
Stock-based compensation	9,601		9,601
Unrealized gain on investments	852			852
Net loss	(35,937)				(35,937)
Ending Balance at Sep. 30, 2024	252,453	$ 6	465,096	914	(213,563)
Ending Balance, Shares at Sep. 30, 2024		56,621,037
Beginning Balance at Jun. 30, 2024	261,242	$ 6	461,977	(217)	(200,524)
Beginning Balance, Shares at Jun. 30, 2024		56,620,014
Exercises of stock options	1		1
Exercises of stock options, Shares		1,023
Stock-based compensation	3,118		3,118
Unrealized gain on investments	1,131			1,131
Net loss	(13,039)				(13,039)
Ending Balance at Sep. 30, 2024	$ 252,453	$ 6	$ 465,096	$ 914	$ (213,563)
Ending Balance, Shares at Sep. 30, 2024		56,621,037

Stock-Based Compensation - Summary of Stock Option Activity (Details)	9 Months Ended
	Sep. 30, 2024 $ / shares shares
Share-Based Payment Arrangement [Abstract]
Options Outstanding, Beginning Balance \| shares	8,561,753
Options, Granted \| shares	2,618,950
Options, Exercised \| shares	(28,088)
Options, Forfeited \| shares	(518,281)
Options Outstanding, Ending Balance \| shares	10,634,334
Weighted-Average Exercise Price, Beginning Balance \| $ / shares	$ 8.67
Weighted-Average Exercise Price, Granted \| $ / shares	2.61
Weighted-Average Exercise Price, Exercised \| $ / shares	0.95
Weighted-Average Exercise Price, Forfeited \| $ / shares	12.41
Weighted-Average Exercise Price, Ending Balance \| $ / shares	$ 7.02

Investment Securities - Summary of Available-for-Sale Investments in an Unrealized Loss Position (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Debt Securities, Available-for-Sale [Line Items]
Estimated Fair Market Value, Less than 12 Months	$ 12,986	$ 65,344
Unrealized Losses, Less than 12 Months	(4)	(132)
Estimated Fair Market Value, 12 Months or Greater	8,227	60,908
Unrealized Losses, 12 Months or Greater	(5)	(304)
Estimated Fair Market Value	21,213	126,252
Unrealized Losses	(9)	(436)
Certificates of deposit
Debt Securities, Available-for-Sale [Line Items]
Estimated Fair Market Value, Less than 12 Months	490	8,514
Unrealized Losses, Less than 12 Months		(14)
Estimated Fair Market Value, 12 Months or Greater	734	1,456
Unrealized Losses, 12 Months or Greater	(1)	(14)
Estimated Fair Market Value	1,224	9,970
Unrealized Losses	(1)	(28)
U.S. Treasury securities
Debt Securities, Available-for-Sale [Line Items]
Estimated Fair Market Value, Less than 12 Months		44,346
Unrealized Losses, Less than 12 Months		(102)
Estimated Fair Market Value, 12 Months or Greater	7,493	51,979
Unrealized Losses, 12 Months or Greater	(4)	(263)
Estimated Fair Market Value	7,493	96,325
Unrealized Losses	(4)	(365)
U.S. Government agency securities
Debt Securities, Available-for-Sale [Line Items]
Estimated Fair Market Value, Less than 12 Months	12,496	12,484
Unrealized Losses, Less than 12 Months	(4)	(16)
Estimated Fair Market Value, 12 Months or Greater		7,473
Unrealized Losses, 12 Months or Greater		(27)
Estimated Fair Market Value	12,496	19,957
Unrealized Losses	$ (4)	$ (43)

Fair Value Measurements - Summary of Financial Instruments Measured at Fair Value on Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, fair value disclosure	$ 253,109	$ 280,217
Money market funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, fair value disclosure	29,363	19,619
Certificates of deposit
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, fair value disclosure	5,110	14,336
U.S. Treasury securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, fair value disclosure	201,136	221,304
U.S. Government agency securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, fair value disclosure	17,500	24,958
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, fair value disclosure	235,609	255,259
Quoted Prices in Active Markets for Identical Assets (Level 1) \| Money market funds
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, fair value disclosure	29,363	19,619
Quoted Prices in Active Markets for Identical Assets (Level 1) \| Certificates of deposit
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, fair value disclosure	5,110	14,336
Quoted Prices in Active Markets for Identical Assets (Level 1) \| U.S. Treasury securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, fair value disclosure	201,136	221,304
Significant Other Observable Inputs (Level 2)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, fair value disclosure	17,500	24,958
Significant Other Observable Inputs (Level 2) \| U.S. Government agency securities
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Investments, fair value disclosure	$ 17,500	$ 24,958

Condensed Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Current assets:
Cash and cash equivalents	$ 30,328	$ 21,200
Investment securities	223,746	260,598
Prepaid expenses and other current assets	3,168	2,786
Total current assets	257,242	284,584
Property and equipment, net	1,559	1,691
Right-of-use asset, related party	2,401	2,938
Other assets	427	430
Total assets	261,629	289,643
Current liabilities:
Accounts payable	1,470	1,940
Accrued expenses and other current liabilities (including related party amounts of $778 and $716 respectively)	5,962	7,682
Total current liabilities	7,432	9,622
Operating lease liability, net, related party	1,744	2,334
Total liabilities	9,176	11,956
Commitments and contingencies (See Note 8)
Stockholders' equity:
Common stock, $0.0001 par value; 200,000,000 shares authorized at September 30, 2024 and December 31, 2023; 56,621,037 and 56,473,598 shares issued and outstanding at June 30, 2024 and December 31, 2023, respectively	6	6
Additional paid-in capital	465,096	455,245
Accumulated deficit	(213,563)	(177,626)
Accumulated other comprehensive income	914	62
Total stockholders' equity	252,453	277,687
Total liabilities and stockholders' equity	$ 261,629	$ 289,643

Stockholders' Deficit - Additional Information (Details) - USD ($) $ in Millions	1 Months Ended	9 Months Ended
	Apr. 30, 2022	Sep. 30, 2024
Maximum
Stockholders Deficit [Line Items]
Aggregate offering price	$ 300.0
ATM Program
Stockholders Deficit [Line Items]
Number of shares sold		0
ATM Program \| Maximum
Stockholders Deficit [Line Items]
Aggregate offering price	$ 100.0

Balance Sheet Details - Summary of Property and Equipment (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Property Plant And Equipment [Line Items]
Property and equipment	$ 3,065	$ 2,750
Less accumulated depreciation	(1,506)	(1,059)
Total	1,559	1,691
Laboratory Equipment
Property Plant And Equipment [Line Items]
Property and equipment	2,291	1,976
Computer Equipment and Software
Property Plant And Equipment [Line Items]
Property and equipment	102	102
Furniture and Fixtures
Property Plant And Equipment [Line Items]
Property and equipment	521	521
Leasehold Improvements
Property Plant And Equipment [Line Items]
Property and equipment	$ 151	$ 151

Stock-Based Compensation - Stock-Based Compensation Expense Reported in Condensed Statements of Operations (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 3,118	$ 3,219	$ 9,601	$ 10,364
Research and Development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	1,524	1,666	4,679	4,767
General and Administrative
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock-based compensation expense	$ 1,594	$ 1,553	$ 4,922	$ 5,597

- 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 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 35
-Paragraph 1D
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480483/718-10-35-1D

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
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-Name Accounting Standards Codification
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480483/718-10-35-3

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-Topic 718
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-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

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-Subparagraph (a)(2)
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Reference 5: http://www.xbrl.org/2003/role/disclosureRef
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-Paragraph 2
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Reference 6: http://www.xbrl.org/2003/role/disclosureRef
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-Paragraph 2
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
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-Section 50
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Reference 10: http://www.xbrl.org/2003/role/disclosureRef
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-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(01)
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-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

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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Reference 13: http://www.xbrl.org/2003/role/disclosureRef
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-Subparagraph (c)(1)(iv)(04)
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-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
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-Section 50
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-Subparagraph (c)(2)(i)
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Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
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-Name Accounting Standards Codification
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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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-Paragraph 2
-Subparagraph (c)(2)(iii)(01)
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-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
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Reference 19: http://www.xbrl.org/2003/role/disclosureRef
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Reference 20: http://www.xbrl.org/2003/role/disclosureRef
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Reference 21: http://www.xbrl.org/2003/role/disclosureRef
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Reference 22: http://www.xbrl.org/2003/role/disclosureRef
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Reference 24: http://www.xbrl.org/2003/role/disclosureRef
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Reference 25: http://www.xbrl.org/2003/role/disclosureRef
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Reference 26: http://www.xbrl.org/2003/role/disclosureRef
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-Topic 718
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-Section 50
-Paragraph 2
-Subparagraph (f)(2)(v)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480429/718-10-50-2

+ Details

Net Loss Per Share

9 Months Ended

Sep. 30, 2024

Earnings Per Share [Abstract]

Net Loss Per Share

3. Net Loss Per Share

Basic net loss per share is computed by dividing the net loss by the weighted-average number of common shares outstanding for the period, without consideration for potentially dilutive securities. Diluted net loss per share is computed by dividing the net loss by the weighted average number of common shares and dilutive common stock equivalents outstanding for the period determined using the treasury-stock and if-converted methods. Dilutive common stock equivalents are comprised of stock options outstanding under the Company’s equity incentive plans, restricted common stock subject to repurchase, and employee stock purchase rights under the Company’s 2021 Employee Stock Purchase Plan (the “ESPP”), as applicable. For all periods presented, there is no difference in the number of shares used to calculate basic and diluted shares outstanding due to the Company's net loss position.


	September 30, 2024		September 30, 2023
Stock options		10,634,334		9,106,844
Shares subject to repurchase		—		1,705
Employee stock purchase plan		133,358		79,498
Total		10,767,692		9,188,047

Investment Securities (Tables)

9 Months Ended

Sep. 30, 2024

Investments, Debt and Equity Securities [Abstract]

Summary of Amortized Cost, Unrealized Gains and Losses, Allowances for Credit Losses and Fair Value of Available-for-Sale Investments Aggregated by Maturity and Security Type

The Company’s investment securities consisted of the following at September 30, 2024 and December 31, 2023 (in thousands):


		As of September 30, 2024
											Estimated
									Allowance		Fair
		Amortized		Unrealized		Unrealized			for Credit		Market
	Maturity	Cost		Gains		Losses			Losses		Value
Certificates of deposits	Within 1 year	$	4,889	$	20	$	(1	)	$	—	$	4,908
U.S. Treasury securities	Within 1 year		164,693		494		(4	)		—		165,183
U.S. Government agency securities	Within 1 year		10,000		4		(2	)		—		10,002
Certificates of deposits	1 year to 2 years		199		3		—			—		202
U.S. Treasury securities	1 year to 2 years		35,551		402		—			—		35,953
U.S. Government agency securities	1 year to 2 years		7,500		—		(2	)		—		7,498
Total		$	222,832	$	923	$	(9	)	$	—	$	223,746

		As of December 31, 2023
											Estimated
									Allowance		Fair
		Amortized		Unrealized		Unrealized			for Credit		Market
	Maturity	Cost		Gains		Losses			Losses		Value
Certificates of deposits	Within 1 year	$	10,488	$	2	$	(23	)	$	—	$	10,467
U.S. Treasury securities	Within 1 year		162,746		70		(349	)		—		162,467
U.S. Government agency securities	Within 1 year		12,499		—		(29	)		—		12,470
Certificates of deposits	1 year to 2 years		3,862		12		(5	)		—		3,869
U.S. Treasury securities	1 year to 2 years		58,441		412		(16	)		—		58,837
U.S. Government agency securities	1 year to 2 years		12,500		2		(14	)		—		12,488
Total		$	260,536	$	498	$	(436	)	$	—	$	260,598

Summary of Available-for-Sale Investments in an Unrealized Loss Position


	As of September 30, 2024
	Less than 12 Months					12 Months or Greater					Total
	Estimated					Estimated					Estimated
	Fair					Fair					Fair
	Market		Unrealized			Market		Unrealized			Market		Unrealized
	Value		Losses			Value		Losses			Value		Losses
Certificates of deposits	$	490	$	—		$	734	$	(1	)	$	1,224	$	(1	)
U.S. Treasury securities		—		—			7,493		(4	)		7,493		(4	)
U.S. Government agency securities		12,496		(4	)		—		—			12,496		(4	)
Total	$	12,986	$	(4	)	$	8,227	$	(5	)	$	21,213	$	(9	)

	As of December 31, 2023
	Less than 12 Months					12 Months or Greater					Total
	Estimated					Estimated					Estimated
	Fair					Fair					Fair
	Market		Unrealized			Market		Unrealized			Market		Unrealized
	Value		Losses			Value		Losses			Value		Losses
Certificates of deposits	$	8,514	$	(14	)	$	1,456	$	(14	)	$	9,970	$	(28	)
U.S. Treasury securities		44,346		(102	)		51,979		(263	)		96,325		(365	)
U.S. Government agency securities		12,484		(16	)		7,473		(27	)		19,957		(43	)
Total	$	65,344	$	(132	)	$	60,908	$	(304	)	$	126,252	$	(436	)

Balance Sheet Details - Summary of Accrued Expenses and Current Liabilities (Details) - USD ($) $ in Thousands	Sep. 30, 2024	Dec. 31, 2023
Accrued Liabilities, Current [Abstract]
Accrued personnel costs	$ 2,989	$ 4,034
Accrued research and development costs	1,616	2,350
Current portion of operating lease liability, net, related party	$ 778	$ 716
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Accounts Payable and Other Accrued Liabilities, Current	Accounts Payable and Other Accrued Liabilities, Current
Accrued other	$ 579	$ 582
Total	$ 5,962	$ 7,682

Leases - Additional Information (Details) $ in Millions	1 Months Ended		3 Months Ended		9 Months Ended
Leases - Additional Information (Details) $ in Millions	Mar. 31, 2022 ft²	Feb. 28, 2021 ft²	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($)	Sep. 30, 2023 USD ($)
Lessee, Lease, Description [Line Items]
Rent expense \| $			$ 0.2	$ 0.2	$ 0.7	$ 0.7
Crossing Holdings, LLC
Lessee, Lease, Description [Line Items]
Area of lease space \| ft²	4,900	12,370
Lease commencement date		2021-09
Lease term		72 months
Option to renew lease term ends, year	2027	2027
Lessee, Operating Lease, Existence of Option to Extend [true false]		true
Lease term, option to extend period		three years
Percentage of annual increase in lease payments		3.00%
Weighted average operating lease remaining lease term			2 years 10 months 24 days		2 years 10 months 24 days
Weighted average operating lease right-of-use asset discount rate			7.37%		7.37%

Condensed Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Cash flows from operating activities
Net loss	$ (35,937)	$ (55,020)
Reconciliation of net loss to net cash used in operating activities:
Depreciation	447	399
Stock-based compensation	9,601	10,364
Amortization of premiums on investment securities, net	(4,760)	(4,248)
Non-cash lease expense	9	28
Change in operating assets and liabilities:
Prepaid expense and other assets	(379)	1,151
Accounts payable and other liabilities	(2,226)	1,564
Net cash used in operating activities	(33,245)	(45,762)
Cash flows from investing activities
Purchases of investment securities	(165,802)	(150,550)
Proceeds from maturities of investment securities	208,265	197,760
Purchases of property and equipment	(340)	(229)
Net cash provided by investing activities	42,123	46,981
Cash flows from financing activities
Issuance of common stock through employee stock purchase plan	223	206
Proceeds from the exercise of stock options	27	17
Net cash provided by financing activities	250	223
Net increase in cash and cash equivalents	9,128	1,442
Cash and cash equivalents at beginning of period	21,200	26,500
Cash and cash equivalents at end of period	$ 30,328	$ 27,942

Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2024

Fair Value Disclosures [Abstract]

Summary of Company's Financial Instruments Measured at Fair Value on a Recurring Basis

The following table summarizes the Company’s financial instruments measured at fair value on a recurring basis at September 30, 2024 and December 31, 2023 (in thousands):


	Fair Value Measurement at End of Period Using:
			Quoted Prices
			In Active
			Markets		Significant
			For		Other		Significant
			Identical		Observable		Unobservable
			Assets		Inputs		Inputs
	Total		(Level 1)		(Level 2)		(Level 3)
As of September 30, 2024:
Assets:
Money market funds(1)	$	29,363	$	29,363	$	—	$	—
Certificates of deposit		5,110		5,110		—		—
U.S. Treasury securities		201,136		201,136		—		—
U.S. Government agency securities		17,500		—		17,500		—
Total	$	253,109	$	235,609	$	17,500	$	—
As of December 31, 2023:
Assets:
Money market funds(1)	$	19,619	$	19,619	$	—	$	—
Certificates of deposit		14,336		14,336		—		—
U.S. Treasury securities		221,304		221,304		—		—
U.S. Government agency securities		24,958		—		24,958		—
Total	$	280,217	$	255,259	$	24,958	$	—

(1)

Included in cash and cash equivalents on the accompanying balance sheets.

License Agreements

9 Months Ended

Sep. 30, 2024

License Agreement [Abstract]

License Agreements

9. License Agreements

In May 2024, the Company entered into a license agreement pursuant to which it received exclusive, worldwide, royalty-bearing, sublicensable rights to certain patents and technology to be used in the development and commercialization of certain products. The Company paid $0.2 million in upfront license fees during the nine months ended September 30, 2024, and zero license fees during the three months ended September 30, 2024. The upfront license fee was expensed to research and development as there is no alternative future use for the license.

The Company may be obligated to make aggregate regulatory milestone payments of up to $0.8 million for each product incorporating licensed patent rights and pay a royalty on worldwide net sales on a product-by-product basis.

The Company may terminate the license agreement with 60 days’ written notice and each party may terminate the license agreement upon 30 days’ written notice for certain breaches of the agreement that remain uncured following 60 days’ notice to the other party of such breach. Unless terminated earlier by the parties, the term of the license agreement will continue until the last valid patent claim expires.

Wisconsin Alumni Research Foundation

In February 2019, the Company entered into a Human Therapeutics Exclusive License Agreement (the “License Agreement”) with the Wisconsin Alumni Research Foundation (“WARF”). Under the License Agreement, the Company licensed the exclusive, worldwide, royalty-bearing, sublicensable rights to certain WARF patents and the nonexclusive worldwide rights to certain know-how to develop and commercialize products for the prevention, diagnosis and treatment of disease. As consideration for the license, the Company agreed to pay an upfront fee of $0.3 million, which the Company immediately expensed as research and development expense in its statements of operations as there was no alternative future use for the license.

In 2022, pursuant to the License Agreement, the Company paid $0.1 million upon the acceptance of an Investigational New Drug Application in the U.S. The Company will be required to make further aggregate milestone payments of up to $17.5 million upon achievement of certain other regulatory and commercial milestones. The Company may also be required to pay royalties based on annual net product sales in the low single digits on its or its sublicensees’ net product sales on a country-by-country and product-by-product basis, and is subject to a minimum royalty of $0.1 million per calendar year upon first commercial product sale. Further, the Company may be required to pay sublicense fees in the mid-single digits percentage for fees, royalties or other payments earned from the granting of sublicenses to the WARF patents and know-how.

The Company is responsible for reimbursing WARF for costs incurred in connection with prosecuting and maintaining patent rights that are specific to the License Agreement. Expenses recognized in connection with legal patent fees under this License Agreement were immaterial for the three and nine months ended September 30, 2024 and 2023, respectively.

The Company may terminate the License Agreement with 90 days written notice or for certain breaches of the agreement. WARF may terminate the License Agreement with 90 days written notice if first commercial sale does not occur before December 31, 2031. Unless terminated earlier by the parties, the term of the License Agreement will continue until the last licensed patent expires in all countries.

Stock-Based Compensation (Tables)

9 Months Ended

Sep. 30, 2024

Share-Based Payment Arrangement [Abstract]

Summary of Stock Option Activity

The following table summarizes stock option activity for the nine months ended September 30, 2024:


	Options			Weighted-Average Exercise Price
Outstanding at December 31, 2023		8,561,753		$	8.67
Granted		2,618,950		$	2.61
Exercised		(28,088	)	$	0.95
Forfeited		(518,281	)	$	12.41
Balance at September 30, 2024		10,634,334		$	7.02

Stock-Based Compensation Expense Reported in Condensed Statements of Operations

Stock-based compensation expense has been reported in the Company's condensed statements of operations as follows (in thousands):


	Three Months Ended September 30,				Nine Months Ended September 30,
	2024		2023		2024		2023
Research and development	$	1,524	$	1,666	$	4,679	$	4,767
General and administrative		1,594		1,553		4,922		5,597
Total	$	3,118	$	3,219	$	9,601	$	10,364

Condensed Statements of Operations (Unaudited) (Parenthetical) - Related Party - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Research and development expenses related party amount	$ 224	$ 247	$ 670	$ 764
General and administrative expenses related party amount	$ 134	$ 132	$ 405	$ 402

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

Leases

9 Months Ended

Sep. 30, 2024

Leases [Abstract]

Leases

7. Leases

In February 2021, the Company entered into a lease agreement with Crossing Holdings, LLC to rent approximately 12,370 square feet of laboratory and office space (the “Lease”). Dr. Pratik Shah and entities that he controls are the sole members of Crossing Holdings, LLC. The Lease commenced in September 2021 with a term of 72 months and an option to extend the lease term for a period of three years; however, it is not reasonably certain the Company will exercise the option to renew when the lease term ends in 2027, and thus, the incremental term was excluded from the calculation of the right-of-use asset or lease liability. Lease payments are subject to annual increases of 3% and the Company is responsible for its share of operating expenses and taxes, which are expensed as incurred. In March 2022, the Company entered into an amendment (the “Lease Amendment”) to its Lease with Crossing Holdings, LLC to rent approximately 4,900 square feet of additional office space in the same building. The Lease Amendment commenced in June 2022 and the term of the additional premises under the Lease Amendment coincides with the term of the Lease and ends in 2027. As of September 30, 2024, the weighted-average remaining lease term for the Company's leases was 2.9 years and the weighted-average discount rate used to determine the right-of-use asset and corresponding operating lease liability was 7.37%.

Maturities of operating lease liabilities as of September 30, 2024 are as follows (in thousands):


2024 (remaining three months)	$	233
2025		945
2026		973
2027		663
Thereafter		—
Total future minimum lease payments		2,814
Less: Present value adjustment		(292	)
Operating lease liabilities	$	2,522

Rent expense for each of the three months ended September 30, 2024 and 2023 was $0.2 million. Rent expense for each of the nine months ended September 30, 2024 and 2023 was $0.7 million.

Organization

9 Months Ended

Sep. 30, 2024

Accounting Policies [Abstract]

Organization

1. Organization

Design Therapeutics, Inc. (the “Company”) was incorporated in Delaware in December 2017 and is based in Carlsbad, California. The Company is a clinical-stage biopharmaceutical company pioneering the research and development of GeneTACTM molecules, which are a novel class of small-molecule gene targeted chimera therapeutic candidates designed to be disease-modifying by addressing the underlying cause of diseases caused by inherited nucleotide repeat expansion mutations. The Company’s lead product candidate is in Friedreich ataxia (“FA”), its second product candidate is in Fuchs endothelial corneal dystrophy (“FECD”), and it is also advancing GeneTACTM programs to address other diseases.

Liquidity and Capital Resources

The accompanying financial statements have been prepared assuming that the Company will continue as a going concern, which contemplates the realization of assets and the satisfaction of liabilities in the normal course of business. The Company has incurred net operating losses since inception and had an accumulated deficit of $213.6 million as of September 30, 2024. The Company had cash, cash equivalents and investment securities of $254.1 million as of September 30, 2024, and has not generated positive cash flow from operations.

Management expects to incur net losses for the foreseeable future. There can be no assurance that the Company will ever earn revenues or achieve profitability, or if achieved, that they will be sustained on a continuing basis. In addition, the research, product development and clinical development activities as well as the commercialization of the Company's products, if approved, will require significant additional financing. The Company may be unable to secure such financing when needed, or if available, such financings may be under terms that are unfavorable to the Company or the current stockholders. If the Company is unable to raise additional funds when needed, it may be required to delay, reduce the scope of, or eliminate development programs, which may adversely affect its business and operations. The Company's currently available cash, cash equivalents and investment securities as of September 30, 2024 are sufficient to meet its anticipated cash requirements for more than 12 months following the date the financial statements are issued.