BALANCE SHEETS (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 36,294	$ 152,822
Investments in marketable securities	210,407	271,416
Prepaid expenses and other current assets	11,466	27,343
Total current assets	258,167	451,581
Property and equipment, net	43,933	43,100
Operating lease right-of-use assets	31,294	31,707
Other long-term assets	12,389	8,436
Total assets	345,783	534,824
Current liabilities:
Accounts payable	9,128	13,692
Accrued expenses and other current liabilities	28,424	26,557
Total current liabilities	37,552	40,249
Operating lease liabilities, net of current portion	48,355	49,099
Total liabilities	85,907	89,348
Contingencies (Note 7)
Stockholders’ equity:
Preferred stock, $0.001 par value per share; 20,000 shares authorized as of March 31, 2022 and December 31, 2021; no shares issued and outstanding as of March 31, 2022 and December 31, 2021	0	0
Common stock, $0.001 par value per share; 200,000 shares authorized as of March 31, 2022 and December 31, 2021; 54,761 and 54,622 shares issued and outstanding as of March 31, 2022 and December 31, 2021, respectively	54	54
Additional paid-in capital	1,070,138	1,058,399
Accumulated other comprehensive loss	(469)	(153)
Accumulated deficit	(809,847)	(612,824)
Total stockholders’ equity	259,876	445,476
Total liabilities and stockholders’ equity	$ 345,783	$ 534,824