Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 94,912	$ 181,727
Marketable securities, current	218,567	189,962
Accounts receivable	3,656	4,484
Prepaid expenses and other current assets	4,876	4,836
Total current assets	322,011	381,009
Marketable securities, non-current	32,495
Property and equipment, net	4,015	3,323
Right-of-use asset	12,909	13,229
Restricted cash	2,577	2,577
Total assets	374,007	400,138
Current liabilities:
Accounts payable	3,742	5,683
Accrued expenses and other current liabilities	6,260	9,524
Deferred revenue, current	26,565	27,603
Operating lease liability, current	1,086	1,042
Total current liabilities	37,653	43,852
Deferred revenue, net of current	50,886	53,617
Operating lease liability, net of current	11,532	11,826
Long-term debt − related party	10,231	10,052
Total liabilities	110,302	119,347
Commitments and contingencies
Stockholders’ equity:
Preferred stock, par value of $0.0001 per share; 10,000,000 shares authorized, and no shares issued or outstanding as of March 31, 2021 and December 31, 2020, respectively
Common stock, par value of $0.0001 per share; 150,000,000 shares authorized, and 43,108,960 and 43,059,632 shares issued and outstanding as of March 31, 2021 and December 31, 2020, respectively	4	4
Additional paid-in capital	468,589	464,597
Accumulated other comprehensive (loss) income	(94)	13
Accumulated deficit	(204,794)	(183,823)
Total stockholders’ equity	263,705	280,791
Total liabilities and stockholders’ equity	$ 374,007	$ 400,138