Unaudited Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Cash flows from operating activities
Net loss	$ (96,537)	$ (78,939)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	853	901
Loss on disposal of property and equipment	0	6
Stock-based compensation	10,806	11,062
Changes in operating assets and liabilities:
Prepaid expenses and other assets	(1,305)	(2,876)
Accounts payable and accrued expenses	12,533	4,146
Right-of-use assets and lease liabilities, net	(443)	(373)
Net cash used in operating activities	(74,093)	(66,073)
Cash flows from investing activities
Purchases of property and equipment	(90)	(237)
Proceeds from sale of property and equipment	0	3
Net cash used in investing activities	(90)	(234)
Cash flows from financing activities
Proceeds from issuance of common stock under Employee Stock Purchase Plan	187	19
Payments for taxes related to net settlement of equity awards	(229)	(571)
Net cash used in financing activities	(42)	(552)
Net decrease in cash and cash equivalents	(74,225)	(66,859)
Cash and cash equivalents, beginning of period	215,507	244,979
Cash and cash equivalents, end of period	141,282	178,120
Supplemental disclosure of non-cash investing and financing activities
Property and equipment additions included in accounts payable and accrued expenses	0	1
Tax related to net settlement of equity awards included in accounts payable and accrued expenses	$ 11	$ 49