Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 44,664	$ 59,537
Receivable related to asset purchase agreement	127
Prepaid expenses and other current assets	2,478	1,915
Total current assets	47,269	61,452
Restricted cash	270	270
Property and equipment, net	492	556
Operating lease right-of-use asset	2,205	2,478
Total assets	50,236	64,756
Current liabilities:
Accounts payable	2,124	3,650
Accrued and other liabilities	9,251	10,356
Total current liabilities	11,375	14,006
Noncurrent operating lease liability	1,295	1,666
Total liabilities	12,670	15,672
Commitments and contingencies
Convertible preferred stock; $0.0001 par value; 10,000 shares authorized as of March 31, 2022 and December 31, 2021; 1,000 shares issued and outstanding as of March 31, 2022 and December 31, 2021; $35,000 liquidation preference as of March 31, 2022 and December 31, 2021 (Note 7)	40,702	40,702
Stockholders' (deficit) equity:
Common stock, $0.0001 par value, 200,000 shares authorized as of March 31, 2022, and December 31, 2021; 78,718 and 77,144 shares issued and outstanding as of March 31, 2022, and December 31, 2021, respectively	8	8
Additional paid-in capital	502,017	499,700
Accumulated deficit	(505,161)	(491,326)
Total stockholders' (deficit) equity	(3,136)	8,382
Total liabilities, convertible preferred stock and stockholders' (deficit) equity	$ 50,236	$ 64,756