Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Cash flows from operating activities:
Net loss	$ (29,487)	$ (27,313)	$ (59,975)	$ (54,227)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Stock-based compensation expense	4,470	3,509	9,041	6,753
Depreciation and amortization expense	800	800	1,735	1,630
Noncash lease expense			2,490	2,251
Accretion of discount on marketable securities			(1,501)	(294)
Changes in operating assets and liabilities:
Prepaid expenses and other current assets			626	(41)
Collaboration receivable			0	300,000
Accounts payable			1,520	(165)
Accrued expenses and other liabilities			(2,819)	(1,455)
Operating lease liabilities			(3,564)	(3,520)
Deferred revenue			(10,908)	(8,410)
Net cash provided by (used in) operating activities			(63,355)	242,522
Cash flows from investing activities:
Purchases of property and equipment			(1,105)	(611)
Purchases of marketable securities			(63,202)	(355,387)
Proceeds from maturities of marketable securities			132,946	72,132
Net cash provided by (used in) investing activities			68,639	(283,866)
Cash flows from financing activities:
Proceeds from issuance of common stock upon exercise of stock options and employee stock purchase plan			205	1,414
Net cash provided by financing activities			205	1,414
Net increase (decrease) in cash, cash equivalents and restricted cash			5,489	(39,930)
Cash, cash equivalents and restricted cash at beginning of period			53,922	102,869
Cash, cash equivalents and restricted cash at end of period	59,411	62,939	59,411	62,939
Supplemental disclosure of noncash investing and financing information:
Cash paid for taxes			1,690	0
Purchases of property and equipment included in accounts payable and accrued expenses			87	210
Reconciliation of cash, cash equivalents and restricted cash:
Cash and cash equivalents	57,703	61,206	57,703	61,206
Restricted cash (current and non-current)	1,708	1,733	1,708	1,733
Total cash, cash equivalents and restricted cash shown in the statement of cash flows	$ 59,411	$ 62,939	$ 59,411	$ 62,939