STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended				9 Months Ended		12 Months Ended
	Sep. 30, 2022	Mar. 31, 2022	Sep. 30, 2021	Mar. 31, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Cash flows from operating activities:
Net loss	$ (24,635)	$ (24,528)	$ (17,410)	$ (11,813)	$ (76,534)	$ (52,821)
Adjustments to reconcile net loss to net cash used in operations:
Stock-based compensation					4,769	4,251
Depreciation					2,068	937
Net amortization of premium on investments					1,509	774
Impairment losses					770	0
Non-cash operating lease expense					220	0
Changes in operating assets and liabilities:
Prepaid expenses and other current assets					3,060	(1,239)
Other assets					(87)	75
Accounts payable					(7,197)	846
Accrued expenses and other current liabilities					1,066	6,431
Non-current operating lease liabilities					(517)	0
Deferred revenue					216	1,044
Deferred rent					0	1,303
Net cash used in operating activities					(70,657)	(38,399)
Cash flows from investing activities:
Purchase of property and equipment					(10,921)	(5,936)
Net change in investments					28,897	(30,108)
Net cash (used in) provided by investing activities					17,976	(36,044)
Cash flows from financing activities:
Proceeds from the exercise of stock options and purchases pursuant to employee stock purchase plan					171	1,639
Net cash provided by financing activities					171	1,639
Net decrease in cash and cash equivalents					(52,510)	(72,804)
Cash and cash equivalents, beginning of period		$ 92,268		$ 157,898	92,268	157,898	$ 157,898
Cash and cash equivalents, end of period	$ 39,758		$ 85,094		39,758	85,094	$ 92,268
Supplemental disclosures of non-cash financial activities:
Operating lease liabilities recognized for operating right-of-use assets					5,447	0
Operating right-of-use assets exchanged for operating lease liabilities					2,945	0
Unpaid amounts related to purchases of property and equipment					$ 221	$ 651