Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
Cash flows from operating activities:
Net loss	$ (105,958)	$ (71,112)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	2,464	1,162
Non-cash lease expense	3,321	999
Net amortization of premium (accretion of discount) on marketable securities	(7,551)	1,231
Stock-based compensation	17,037	9,853
Change in fair value of success payments liabilities	(76)	(2,615)
Changes in operating assets and liabilities:
Prepaid expenses and other assets	(2,955)	(2,894)
Accounts payable	1,471	(1,017)
Accrued expenses and other liabilities	(549)	5,176
Operating lease liabilities	(4,262)	(1,048)
Net cash used in operating activities	(97,058)	(60,265)
Cash flows from investing activities:
Purchases of property and equipment	(6,037)	(5,627)
Purchases of marketable securities	(246,877)	(74,249)
Maturities of marketable securities	301,331	147,750
Net cash provided by investing activities	48,417	67,874
Cash flows from financing activities:
Proceeds from issuance of common stock, net of issuance costs	1,922	0
Proceeds from exercise of stock options	664	625
Issuance of common stock under employee stock purchase plan	685	325
Net cash provided by financing activities	3,271	950
Increase (decrease) in cash, cash equivalents and restricted cash	(45,370)	8,559
Cash, cash equivalents and restricted cash—beginning of period	120,236	69,567
Cash, cash equivalents and restricted cash—end of period	74,866	78,126
Supplemental disclosure of noncash investing and financing activities:
Property and equipment additions included in accounts payable and accrued expenses	$ 532	$ 1,169