Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Cash flows from operating activities
Net loss	$ (19,306)	$ (56,163)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	423	319
Net amortization of premiums and discounts on marketable securities	(1,117)	(1,411)
Stock-based compensation	4,660	6,407
Non-cash operating lease expense	745	669
Other non-cash items	70	152
Changes in operating assets and liabilities:
Accounts receivable	0	30,000
Prepaid expenses and other current assets	580	620
Accounts payable	(4,166)	4,728
Accrued expenses	(6,042)	(10,327)
Operating lease liabilities	(630)	(697)
Deferred revenue	(7,874)	(3,302)
Net cash used in operating activities	(32,657)	(29,005)
Cash flows from investing activities
Maturities of marketable securities	15,000	66,000
Purchase of marketable securities	(87,415)	(63,693)
Purchase of property and equipment	(132)	(911)
Net cash (used in) provided by investing activities	(72,547)	1,396
Cash flows from financing activities
Net proceeds from at-the-market facilities	5,846	21,730
Proceeds from exercise of stock options	48	34
Payment of debt issuance costs	0	(150)
Payments under finance lease obligations	(65)	(65)
Net cash provided by financing activities	5,829	21,549
Decrease in cash, cash equivalents and restricted cash	(99,375)	(6,060)
Cash, cash equivalents and restricted cash, beginning of period	175,039	129,363
Cash, cash equivalents and restricted cash, end of period	75,664	123,303
Supplemental cash flow information:
Purchases of property and equipment in accounts payable and accrued expenses	0	169
Common stock issuance costs in accounts payable and accrued expenses	65	66
Cash paid for interest	$ 871	$ 791