CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Cash flows from operating activities:
Net loss	$ (22,955)	$ (35,615)
Adjustments to reconcile net loss to net cash used in operating activities:
Accretion of discount on investments	(267)	9
Amortization of right of use assets	390	307
Depreciation expense	454	676
Stock-based compensation including ESPP	3,664	3,786
Changes in operating assets and liabilities:
Other assets	2,086	3,620
Right of use assets		(278)
Accounts payable	(1,915)	740
Accrued liabilities	(937)	(6,071)
Operating lease liabilities	(584)	(47)
Other liabilities	0	1
Deferred revenue from collaborations	(2,323)	12,438
Net cash and cash equivalents used in operating activities	(22,387)	(20,434)
Activities in available-for-sale investments:
Maturities of investments	20,000
Purchase of short-term investments	0	(59,889)
Purchases of property and equipment	(7)	(515)
Net cash and cash equivalents provided by (used in) investing activities	19,993	(60,404)
Cash flows from financing activities:
Payments on finance lease	(24)	(31)
Proceeds from the exercise of common stock option	23	10
Net cash and cash equivalents used in financing activities	(1)	(21)
Net decrease in cash, cash equivalents, and restricted cash	(2,395)	(80,859)
Cash, cash equivalents, and restricted cash, beginning of period	81,463	186,980
Cash, cash equivalents, and restricted cash, end of period	79,068	106,121
Reconciliation to amounts on the consolidated balance sheet:
Cash and cash equivalents	78,671	104,562
Restricted cash	397	1,559
Cash, cash equivalents, and restricted cash, end of period	79,068	106,121
Supplemental disclosures of noncash financing and investing activities:
Mark to market adjustment for available-for-sale investments	98	(248)
Vesting of early exercised options	$ 21	$ 84