Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Cash flows from operating activities:
Net loss	$ (26,914)	$ (22,986)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Stock-based compensation expense	3,244	1,888
Depreciation and amortization expense	811	772
Noncash lease expense	1,114	1,062
Noncash interest expense	0	85
Amortization (accretion) of premium/discount on marketable securities	38	(13)
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	184	(295)
Collaboration receivable	300,000	0
Accounts payable	1,271	(754)
Accrued expenses and other liabilities	(2,542)	(2,609)
Operating lease liabilities	(1,752)	(11)
Deferred revenue	(3,920)	(286)
Net cash provided by (used in) operating activities	271,534	(23,147)
Cash flows from investing activities:
Purchases of property and equipment	(247)	(1,794)
Purchases of marketable securities	(212,294)	(26,467)
Proceeds from maturities of marketable securities	53,132	25,000
Net cash used in investing activities	(159,409)	(3,261)
Cash flows from financing activities:
Proceeds from issuance of common stock upon exercise of stock options and employee stock purchase plan	384	62
Net cash provided by financing activities	384	62
Net increase (decrease) in cash, cash equivalents and restricted cash	112,509	(26,346)
Cash, cash equivalents and restricted cash at beginning of period	102,869	94,528
Cash, cash equivalents and restricted cash at end of period	215,378	68,182
Supplemental cash flow information:
Cash paid for interest	0	400
Supplemental disclosure of noncash investing and financing information:
Purchases of property and equipment included in accounts payable and accrued expenses	239	959
Reconciliation of cash, cash equivalents and restricted cash:
Cash and cash equivalents	213,645	66,449
Restricted cash	1,733	1,733
Total cash, cash equivalents and restricted cash shown in the statement of cash flows	$ 215,378	$ 68,182