Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Cash flows from operating activities
Net loss	$ (56,163)	$ (47,258)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	319	205
Net amortization of premiums and discounts on marketable securities	(1,411)	0
Stock-based compensation	6,407	5,485
Other non-cash items	152	194
Changes in operating assets and liabilities:
Accounts receivable	30,000	0
Prepaid expenses and other current assets	620	(462)
Accounts payable	4,728	(2,524)
Accrued expenses	(10,327)	(2,159)
Operating lease right-of-use assets	669	889
Operating lease liabilities	(697)	(579)
Deferred revenue	(3,302)	38,254
Net cash used in operating activities	(29,005)	(7,955)
Cash flows from investing activities
Maturities of marketable securities	66,000	0
Purchase of marketable securities	(63,693)	0
Purchase of property and equipment	(911)	(329)
Net cash provided by (used in) investing activities	1,396	(329)
Cash flows from financing activities
Net proceeds from at-the-market facilities	21,730	60,374
Proceeds from exercise of stock options	34	96
Payment of debt issuance costs	(150)	0
Payments under finance lease obligations	(65)	(76)
Net cash provided by financing activities	21,549	60,394
(Decrease) increase in cash, cash equivalents and restricted cash	(6,060)	52,110
Cash, cash equivalents and restricted cash, beginning of period	129,363	178,425
Cash, cash equivalents and restricted cash, end of period	123,303	230,535
Supplemental disclosures of non-cash activities:
Purchases of property and equipment in accounts payable and accrued expenses	169	457
Common stock issuance costs in accounts payable and accrued expenses	66	0
Cash paid for interest	$ 791	$ 531