Organization and Summary of Significant Accounting Policies (Tables)

3 Months Ended

Mar. 31, 2024

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Summary of Financial Instruments Measured at Fair Value on Recurring Basis

The following tables summarize the Company’s financial instruments measured at fair value on a recurring basis (in thousands):

			Fair Value Measurements at Reporting Date Using
	Total		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
As of March 31, 2024:
Assets:
Cash equivalents:
Money market funds	$	211,890	$	211,890	$	—	$	—
Total cash equivalents		211,890		211,890		—		—
Short-term investments:
U.S. Treasury securities		74,519		74,519		—		—
U.S. agency bonds		191,460		—		191,460		—
Asset-backed securities		5,114		—		5,114		—
Corporate debt securities		120,741		—		120,741		—
Commercial paper		47,126		—		47,126		—
Total short-term investments		438,960		74,519		364,441		—
Restricted cash:
Money market account		816		816		—		—
Total restricted cash		816		816		—		—
Total assets measured at fair value on a recurring basis	$	651,666	$	287,225	$	364,441	$	—

			Fair Value Measurements at Reporting Date Using
	Total		Quoted Prices in Active Markets for Identical Assets (Level 1)		Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
As of December 31, 2023:
Assets:
Cash equivalents:
Money market funds	$	14,751	$	14,751	$	—	$	—
Total cash equivalents		14,751		14,751		—		—
Short-term investments:
U.S. Treasury securities		71,300		71,300		—		—
U.S. agency bonds		167,103		—		167,103		—
Asset-backed securities		5,055		—		5,055		—
Corporate debt securities		1,999		—		1,999		—
Commercial paper		79,366		—		79,366		—
Total short-term investments		324,823		71,300		253,523		—
Restricted cash:
Money market account		816		816		—		—
Total restricted cash		816		816		—		—
Total assets measured at fair value on a recurring basis	$	340,390	$	86,867	$	253,523	$	—

Reconciliation of Cash and Cash Equivalents and Restricted Cash

The following table provides a reconciliation of cash and cash equivalents and restricted cash reported within the accompanying balance sheets that sum to the amounts shown in the statements of cash flows (in thousands):

	March 31, 2024		December 31, 2023
Cash and cash equivalents	$	212,803	$	19,205
Restricted cash		816		816
Total cash and cash equivalents and restricted cash	$	213,619	$	20,021

Summary of Short-Term Investments

The following tables summarize short-term investments (in thousands):

	As of March 31, 2024
	Amortized		Unrealized					Estimated
	Cost		Gains		Losses			Fair Value
U.S. Treasury securities	$	74,555	$	1	$	(37	)	$	74,519
U.S. agency bonds		191,844		127		(511	)		191,460
Asset-backed securities		5,130		—		(16	)		5,114
Corporate debt securities		120,839		47		(145	)		120,741
Commercial paper		47,116		10		—			47,126
Total	$	439,484	$	185	$	(709	)	$	438,960

	As of December 31, 2023
	Amortized		Unrealized					Estimated
	Cost		Gains		Losses			Fair Value
U.S. Treasury securities	$	71,072	$	242	$	(14	)	$	71,300
U.S. agency bonds		166,699		591		(187	)		167,103
Asset-backed securities		5,078		—		(23	)		5,055
Corporate debt securities		1,999		—		—			1,999
Commercial paper		79,310		56		—			79,366
Total	$	324,158	$	889	$	(224	)	$	324,823

The amortized cost and estimated fair value in the tables above exclude $3.9 million and $2.2 million of accrued interest receivable as of March 31, 2024 and December 31, 2023, respectively. Accrued interest receivable is included in prepaid expenses and other current assets in the accompanying balance sheets.

Schedule of Contractual Maturities of Available-for-sale Debt Securities

Contractual maturities of available-for-sale debt securities are as follows (in thousands):

	As of March 31, 2024
	Due in 1 Year or Less		Due Between 1 and 3 Years
U.S. Treasury securities	$	52,037	$	22,482
U.S. agency bonds		70,515		120,945
Asset-backed securities		5,114		—
Corporate debt securities		—		120,741
Commercial paper		47,126		—
Total	$	174,792	$	264,168

	As of December 31, 2023
	Due in 1 Year or Less		Due Between 1 and 3 Years
U.S. Treasury securities	$	34,426	$	36,874
U.S. agency bonds		89,801		77,302
Asset-backed securities		5,055		—
Corporate debt securities		1,999		—
Commercial paper		79,366		—
Total	$	210,647	$	114,176

Schedule of Available-for-Sale Debt Securities in an Unrealized Loss Position

The following tables summarize our available-for-sale debt securities in an unrealized loss position for which an allowance for credit losses has not been recorded, aggregated by major security type and length of time in a continuous unrealized loss position (in thousands):

	As of March 31, 2024
	Less Than 12 Months					12 Months or Longer					Total
	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
U.S. Treasury securities	$	55,943	$	(37	)	$	—	$	—		$	55,943	$	(37	)
U.S. agency bonds		124,677		(511	)		—		—			124,677		(511	)
Asset-backed securities		—		—			5,114		(16	)		5,114		(16	)
Corporate debt securities		83,338		(145	)		—		—			83,338		(145	)
Total	$	263,958	$	(693	)	$	5,114	$	(16	)	$	269,072	$	(709	)

	As of December 31, 2023
	Less Than 12 Months					12 Months or Longer					Total
	Fair Value		Unrealized Losses			Fair Value		Unrealized Losses			Fair Value		Unrealized Losses
U.S. Treasury securities	$	5,892	$	(14	)	$	—	$	—		$	5,892	$	(14	)
U.S. agency bonds		63,583		(169	)		9,970		(18	)		73,553		(187	)
Asset-backed securities		5,055		(23	)		—		—			5,055		(23	)
Total	$	74,530	$	(206	)	$	9,970	$	(18	)	$	84,500	$	(224	)

Summary of Potentially Dilutive Shares Not Included in the Calculation of Net Loss Per Share

Potentially dilutive securities not included in the calculation of diluted net loss per share, because to do so would be anti-dilutive, are as follows (in common stock equivalent shares):

	March 31,
	2024		2023
Common stock options		9,850,776		8,889,905
Unvested common stock		5,771		30,508
Employee stock purchase plan shares		55,251		44,231
Total potentially dilutive shares		9,911,798		8,964,644