Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 65,657	$ 56,045
Marketable securities	84,736	98,104
Unbilled receivable	30,000	0
Prepaid expenses and other current assets	3,892	3,197
Total current assets	184,285	157,346
Property and equipment, net	5,384	5,651
Operating lease right-of-use asset	26,011	25,870
Restricted cash	1,595	1,595
Other assets	405	385
Total assets	217,680	190,847
Current liabilities:
Accounts payable	2,625	1,550
Accrued expenses and other current liabilities	10,530	13,089
Operating lease liability	5,693	5,384
Convertible note payable	713	0
Total current liabilities	19,561	20,023
Operating lease liability, non-current	26,684	26,909
Convertible note payable, non-current	24,448	25,015
Total liabilities	70,693	71,947
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.0001 par value per share; 5,000,000 shares authorized    at March 31, 2022 and December 31, 2021; no shares    issued and outstanding at March 31, 2022 and December 31, 2021	0	0
Common stock, $0.0001 par value; 150,000,000 shares    authorized at March 31, 2022 and December 31, 2021, respectively;    54,347,564 and 45,958,776 shares issued and outstanding at March 31, 2022    and December 31, 2021, respectively	6	5
Additional paid-in capital	282,436	259,859
Accumulated other comprehensive loss	(911)	(221)
Accumulated deficit	(134,544)	(140,743)
Total stockholders’ equity	146,987	118,900
Total liabilities and stockholders’ equity	$ 217,680	$ 190,847