Unaudited Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Operating activities:
Net loss	$ (24,663)	$ (48,681)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	68	227
Stock-based compensation	4,364	5,260
Non-cash interest expense	485	193
Amortization (accretion) of premiums/discounts on investments, net	(2)	320
Amortization of right-of-use asset	179	502
Gain from lease termination and asset sale	(508)
Changes in operating assets and liabilities
Prepaid expenses and other current assets	28	1,995
Accounts payable and accrued liabilities	(4,138)	5,407
Lease liability	(196)	(549)
Net cash used in operating activities	(24,383)	(35,326)
Investing activities:
Purchases of property and equipment		(8)
Proceeds from asset sale	700
Purchases of short-term investments	(12,676)	(39,176)
Sales and maturities of short-term investments	40,200	65,941
Net cash provided by investing activities	28,224	26,757
Financing activities:
Proceeds from exercise of common stock options		1,096
Repurchase of unvested common stock		(1)
Deferred issuance costs		(37)
Proceeds from issuance of common stock from employee stock purchase plan	1	147
Net cash provided by financing activities	1	1,205
Net increase (decrease) in cash and cash equivalents	3,842	(7,364)
Cash and cash equivalents at beginning of period	48,910	24,393
Cash and cash equivalents at end of period	52,752	17,029
Supplemental disclosure of cash flow information:
Cash paid for interest	962	552
Supplemental non-cash investing and financing activities:
Vesting of common stock	$ 3	20
Issuance costs in accounts payable and accrued liabilities		$ 401