STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Cash flows from operating activities:
Net loss	$ (20,287)	$ (21,009)	$ (43,446)	$ (37,518)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation			498	451
Stock-based compensation expense			8,037	5,957
Loss on fixed asset disposals			0	3
(Accretion of discount) amortization of premium on investments, net			(52)	870
Changes in operating assets and liabilities:
Prepaid expenses and other assets			(2,112)	307
Accounts payable and accrued other liabilities			(3,419)	(1,185)
Net cash used in operating activities			(40,494)	(31,115)
Cash flows from investing activities:
Acquisitions of property and equipment			(1,390)	(317)
Purchases of investments			(145,473)	(25,171)
Maturities of investments			10,000	148,500
Net cash (used in) provided by investing activities			(136,863)	123,012
Cash flows from financing activities:
Issuance costs associated with financings			0	(339)
Proceeds from issuance of common stock under the Employee Stock Purchase Plan			354	0
Proceeds from stock option exercises			77	74
Net cash provided by (used in) financing activities			431	(265)
Net (decrease) increase in cash, cash equivalents and restricted cash			(176,926)	91,632
Cash, cash equivalents and restricted cash at beginning of period			226,474	78,446
Cash, cash equivalents and restricted cash at end of period	49,548	170,078	49,548	170,078
Cash and cash equivalents	49,080	170,078	49,080	170,078
Restricted cash included in other assets	468	0	468	0
Total cash, cash equivalents and restricted cash	$ 49,548	$ 170,078	$ 49,548	$ 170,078