Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Cash flows from operating activities:
Net loss	$ (5,602)	$ (10,616)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation expense		27
Stock based compensation expense	2,249	1,503
Changes in operating assets and liabilities:
Prepaid expenses and other assets	275	399
Accounts payable	(277)	(255)
Accrued liabilities	3	974
Net cash used in operating activities	(3,352)	(7,968)
Cash flows from financing activities:
Proceeds from exercise of stock options and ESPP	12	42
Payment of deferred financing costs	(156)	(44)
Net cash used in financing activities	(144)	(2)
Net decrease in cash and cash equivalents	(3,496)	(7,970)
Cash and cash equivalents — beginning of period	42,044	58,765
Cash and cash equivalents — end of period	38,548	$ 50,795
Supplemental disclosure of non-cash investing and financing activities:
Unpaid Deferred Transaction Costs	$ 29