CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Cash flows used in operating activities:
Net loss	$ (39,397)	$ (23,840)
Adjustments to reconcile net loss to net cash used in operating activities
Non cash lease expense	2,831	1,775
Change in fair value of short-term investment — related party	1,701	4,485
Stock-based compensation expense	1,681	1,123
Depreciation expense	1,052	293
Amortization of premiums and discount on short-term investments	(611)	193
Deferred income taxes	(202)	(532)
Non cash other income (expense)	0	0
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(1,285)	292
Accounts payable	(504)	1,047
Accrued expenses and other current liabilities	(4,046)	(33,321)
Lease liabilities	(2,781)	(2,308)
Net cash used in operating activities	(41,561)	(50,793)
Cash flows (used in) provided by investing activities:
Purchases of property and equipment	(1,999)	(1,688)
Purchases of investments	(45,666)	0
Maturities of investments	35,000	32,500
Payments of security deposits	0	81
Net cash (used in) provided by investing activities	(12,665)	30,893
Cash flows provided by (used in) financing activities:
Payments of deferred offering costs	0	(1,272)
Net proceeds from stock option exercises	68	0
Net cash provided by (used in) financing activities	68	(1,272)
Net change in cash, cash equivalents, and restricted cash	(54,158)	(21,172)
Cash, cash equivalents, and restricted cash at beginning of period	201,116	198,545
Cash, cash equivalents, and restricted cash at end of period	146,958	177,373
Reconciliation of cash, cash equivalents and restricted cash:
Total cash, and cash equivalents	146,958	177,373
Less: restricted cash	13,496	13,125
Cash and cash equivalents	133,462	164,248
Supplemental disclosure of non-cash investing and financing activities:
Purchases of property and equipment included in accounts payable and accrued expenses	2,603	1,144
Settlement of forward contract — related party	0	12,020
Deferred offering costs included in accounts payable and accrued expenses	$ 0	$ 547