Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022
Operating activities
Net loss	$ (97,335)	$ (109,872)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation expense	2,172	2,414
Stock-based compensation expense	14,802	13,350
Net (accretion of discounts) amortization of premiums on marketable securities	(5,991)	152
Changes in operating assets and liabilities:
Accounts receivable	0	2,500
Unbilled accounts receivable	(308)	908
Prepaid expenses and other current assets	(1,072)	(170)
Operating lease assets and liabilities	(715)	(372)
Other assets	94	(1,562)
Accounts payable	(853)	(1,176)
Accrued expenses and other liabilities	(825)	555
Deferred revenue	(934)	(3,777)
Net cash used in operating activities	(90,965)	(97,050)
Investing activities
Purchases of marketable securities	(194,892)	(151,153)
Maturities of marketable securities	158,708	165,529
Purchases of property and equipment	(508)	(1,963)
Net cash (used in) provided by investing activities	(36,692)	12,413
Financing activities
Proceeds from issuance of common stock in connection with public offerings, net of issuance costs	117,345	80,804
Proceeds from issuance of common stock under benefit plans, net	777	3,519
Net cash provided by financing activities	118,122	84,323
Net (decrease) increase in cash, cash equivalents and restricted cash	(9,535)	(314)
Cash, cash equivalents, and restricted cash, beginning of period	36,190	36,504
Cash, cash equivalents, and restricted cash, end of period	26,655	36,190
Supplemental cash flow information
Cash paid for operating lease liabilities	3,333	2,219
Non-cash investing and financing activities:
Property and equipment purchases unpaid at end of period		26
Cash and cash equivalents	25,563	35,098
Restricted cash	$ 1,092	$ 1,092