CONDENSED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Cash flows from operating activities:
Net loss	$ (20,724)	$ (24,528)
Adjustments to reconcile net loss to net cash used in operations:
Stock-based compensation	1,683	1,513
Depreciation	1,014	472
Non-cash operating lease expense	85	65
Net amortization (accretion) of investments	(213)	981
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	1,462	3,699
Other assets	30	25
Accounts payable	(2,197)	(7,738)
Accrued expenses and other current liabilities	(7,356)	(601)
Non-current operating lease liabilities	(188)	(165)
Deferred revenue	(57)	0
Net cash used in operating activities	(26,461)	(26,277)
Cash flows from investing activities:
Purchases of property and equipment	(75)	(2,488)
Net change in investments	45,200	(12,894)
Net cash provided by (used in) investing activities	45,125	(15,382)
Cash flows from financing activities:
Proceeds from the exercises of stock options and purchases pursuant to employee stock purchase plan	39	134
Taxes paid related to net share settlement of equity awards	(39)	0
Net cash provided by financing activities	0	134
Net increase (decrease) in cash and cash equivalents	18,664	(41,525)
Cash and cash equivalents, beginning of period	47,379	92,268
Cash and cash equivalents, end of period	66,043	50,743
Supplemental disclosures of non-cash financial activities:
Operating lease liabilities recognized for operating right-of-use assets	0	5,447
Operating right-of-use assets exchanged for operating lease liabilities	0	2,945
Deferred revenue billed but not received	500	0
Unpaid amounts related to purchases of property and equipment	$ 155	$ 319