STATEMENTS OF CASH FLOWS (UNAUDITED) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Cash flows used in operating activities:
Net loss	$ (31,431)	$ (27,718)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	426	278
Noncash lease expense	414	432
Stock-based compensation	5,547	6,256
Amortization of premium and discount on marketable securities, net	(1,541)	(446)
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(788)	(355)
Accounts payable	631	374
Accrued expenses and other liabilities	(5,692)	(1,903)
Long-term prepaid expenses and other long-term assets		(6,610)
Operating lease liabilities	643	(442)
Net cash used in operating activities	(31,791)	(30,134)
Cash flows provided by investing activities:
Purchases of marketable securities	(5,490)	(7,191)
Proceeds from maturities of marketable securities	37,000	26,000
Purchases of property and equipment	(289)	(810)
Net cash provided by investing activities	31,221	17,999
Cash flows used in financing activities:
Payment of offering costs		(297)
Proceeds from the issuance of common stock in connection with the exercise of stock options	2	28
Payment of withholding taxes related to stock-based compensation to employees	(16)
Net cash used in financing activities	(14)	(269)
Net decrease in cash, cash equivalents and restricted cash	(584)	(12,404)
Cash, cash equivalents, and restricted cash at beginning of period	29,335	34,649
Cash, cash equivalents, and restricted cash at end of period	28,751	22,245
Supplemental disclosures:
Operating lease right-of-use assets obtained in exchange for operating lease liabilities	109
Property and equipment in accounts payable and accrued expenses and other current liabilities	269	21
Unrealized (loss) gain on marketable securities	$ (458)	$ 1,294