Condensed Consolidated Balance Sheets (unaudited) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
CURRENT ASSETS
Cash and cash equivalents	$ 35,243	$ 34,863
Marketable securities	3,235	20,848
Development receivables	330	375
Prepaid expenses and other current assets	5,567	6,172
Total current assets	44,375	62,258
Restricted cash	1,310	1,553
Property and equipment, net	3,424	3,220
Operating lease right-of-use assets	3,266	3,430
Other non-current assets	78	683
TOTAL ASSETS	52,453	71,144
CURRENT LIABILITIES
Accounts payable	2,062	677
Operating lease liabilities	608	625
Deferred revenue	302	517
Accrued and other current liabilities	9,665	12,837
Total current liabilities	12,637	14,656
Non-current operating lease liabilities	3,823	4,004
Deferred revenue, net of current portion	2,341	2,179
TOTAL LIABILITIES	18,801	20,839
Commitments and Contingencies (Note 7)
STOCKHOLDERS’ EQUITY
Preferred stock, $0.0001 par value; 10,000,000 shares authorized as of March 31, 2023 and December 31, 2022; no shares issued and outstanding as of March 31, 2023 and December 31, 2022	0	0
Common stock, $0.0001 par value; 500,000,000 shares authorized as of March 31, 2023 and December 31, 2022; 65,395,159 shares and 65,350,343 shares issued and outstanding as of March 31, 2023 and December 31, 2022, respectively	6	6
Additional paid-in capital	477,698	475,971
Accumulated other comprehensive loss	(6)	(48)
Accumulated deficit	(444,046)	(425,624)
TOTAL STOCKHOLDERS’ EQUITY	33,652	50,305
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ 52,453	$ 71,144