CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Cash flows used in operating activities:
Net loss	$ (81,782)	$ (53,188)
Adjustments to reconcile net loss to net cash used in operating activities
Non cash lease expense	6,304	4,222
Stock-based compensation expense	5,264	2,468
Depreciation expense	2,170	723
Change in fair value of short-term investment — related party	1,438	8,208
Amortization of premiums and discount on short-term investments	(1,403)	249
Deferred income taxes	(171)	(974)
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	(5,299)	(43)
Accounts payable	1,104	2,428
Accrued expenses and other current liabilities	(3,438)	(30,851)
Lease liabilities	(6,569)	(4,258)
Net cash used in operating activities	(82,382)	(71,016)
Cash flows provided by (used in) investing activities:
Maturities of investments	65,000	62,000
Purchases of investments	(45,659)	(74,744)
Purchases of property and equipment	(3,975)	(6,490)
Payments of security deposits	(170)	(664)
Net cash provided by (used in) investing activities	15,196	(19,898)
Cash flows provided by (used in) financing activities:
Payments of deferred offering costs	0	(1,896)
Net proceeds from stock option exercises	143	0
Net cash provided by (used in) financing activities	143	(1,896)
Net change in cash, cash equivalents, and restricted cash	(67,043)	(92,810)
Cash, cash equivalents, and restricted cash at beginning of period	201,116	198,545
Cash, cash equivalents, and restricted cash at end of period	134,073	105,735
Reconciliation of cash, cash equivalents and restricted cash:
Total cash, and cash equivalents	134,073	105,735
Less: restricted cash	13,496	13,496
Cash and cash equivalents	120,577	92,239
Supplemental cash flow information:
Right-of-use assets obtained in exchange for new operating lease liabilities	3,265	28,573
Supplemental disclosure of non-cash investing and financing activities:
Purchases of property and equipment included in accounts payable and accrued expenses	712	2,583
Settlement of forward contract — related party	0	12,020
Deferred offering costs included in accounts payable and accrued expenses	$ 0	$ 244