CONDENSED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Cash flows from operating activities:
Net loss	$ (38,522)	$ (34,520)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	2,096	1,394
Amortization of premiums and discounts on marketable securities	1,906	1,603
Stock-based compensation	4,870	5,295
Changes in operating assets and liabilities:
Prepaid expenses and other assets	540	(4,577)
Accounts payable	330	(2,550)
Accrued liabilities	(1,124)	717
Deferred rent	(32)	1,505
Net cash used in operating activities	(29,936)	(31,133)
Cash flows from investing activities:
Maturities of marketable securities	54,231	136,425
Purchases of marketable securities	(7,889)	(102,258)
Purchases of property and equipment	(719)	(979)
Net cash provided by investing activities	45,623	33,188
Cash flows from financing activities:
Proceeds from exercise of stock options	66	76
Proceeds from shares issued under ESPP	73
Payments of the term loan		(834)
Net cash provided by (used in) financing activities	139	(758)
Net increase in cash, cash equivalents and restricted cash	15,826	1,297
Cash, cash equivalents and restricted cash - beginning of period	12,376	36,284
Cash, cash equivalents and restricted cash - end of period	28,202	37,581
Supplemental disclosures of cash flow information:
Cash paid for interest	$ 46	$ 67