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	$ (58,749)	$ (65,756)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,451	1,358
Non-cash interest expense	141	164
Stock-based compensation expense	5,452	6,609
Loss on disposal of property and equipment	3	1
Changes in operating assets and liabilities:
Prepaid and other assets	(597)	1,283
Operating lease right-of-use asset	338	288
Accounts payable	(1,625)	(972)
Accrued expenses and other liabilities	(928)	116
Operating lease liability	(679)	(591)
Net cash used in operating activities	(55,193)	(57,500)
Cash flows from investing activities:
Purchases of property and equipment	(486)	(1,358)
Net cash used in investing activities	(486)	(1,358)
Cash flows from financing activities:
Repayments of debt principal	(5,000)
Payments of finance lease	(64)	(64)
Proceeds from issuance of common stock under employee stock purchase plan	140
Proceeds from exercise of stock options	8	16
Net cash used in financing activities	(4,916)	(48)
Decrease in cash, cash equivalents and restricted cash	(60,595)	(58,906)
Cash, cash equivalents and restricted cash, beginning of period	121,947	199,606
Cash, cash equivalents and restricted cash, end of period	61,352	140,700
Supplemental cash flow disclosure:
Cash paid for interest	474	380
Supplemental disclosure of non-cash activities:
Capital expenditures included in accounts payable or accrued expenses		371
Reconciliation to amounts within the condensed consolidated balance sheets:
Cash and cash equivalents	59,772	139,143
Restricted cash	1,580	1,557
Cash, cash equivalents and restricted cash, end of period	$ 61,352	$ 140,700