Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Operating activities:
Net loss	$ (7,947)	$ (13,022)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	534	511
Stock-based compensation	916	475
Non-cash operating lease expense	367	309
Amortization of premium on marketable securities, net	116	0
Change in fair value of warrant liabilities	(6,497)	0
Changes in operating assets and liabilities:
Prepaid expenses and other current assets	274	(328)
Other assets	(24)	(1)
Accounts payable	(1,755)	431
Accrued and other liabilities	(3,782)	1,800
Operating Lease liabilities	(576)	(507)
Net cash used in operating activities	(18,374)	(10,332)
Investing activities:
Purchases of property and equipment	(412)	(343)
Purchases of marketable securities	0	(1,099)
Net cash used in investing activities	(412)	(1,442)
Financing activities:
Proceeds from exercise of stock options	0	196
Net cash provided by financing activities	0	196
Net decrease in cash, cash equivalents and restricted cash	(18,786)	(11,578)
Cash, cash equivalents and restricted cash at beginning of period	33,496	35,387
Cash, cash equivalents and restricted cash at end of period	14,710	23,809
Supplemental disclosure of noncash investing and financing activities:
Deferred costs related to Equity Purchase Agreement included in accounts payable, accrued liabilities and additional paid-in capital	432	0
Transaction costs in Business Combination included in accrued liabilities	0	267
Purchases of property and equipment included in accounts payable	0	37
Vesting of early exercises of stock options	30	30
Reclassification of early exercised stock options to liability	0	120
Reconciliation Of Cash Cash Equivalents And Restricted Cash To Consolidated Balance Sheets Abstract
Cash and cash equivalents	14,305	23,404
Restricted cash	405	405
Cash, cash equivalents and restricted cash	$ 14,710	$ 23,809