CONDENSED CONSOLIDATED BALANCE SHEETS (UNAUDITED) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 248,127	$ 108,382
Short-term investments	7,999	47,491
Assets held for sale		28,907
Prepaid expenses and other current assets	6,322	7,129
Total current assets	262,448	191,909
Equity method investment	30,639
Property and equipment, net	1,986	2,252
Right-of-use assets	15,609	15,607
Restricted cash	276	1,953
Total assets	310,958	211,721
Current liabilities:
Accounts payable	9,885	2,366
Accrued expenses and other liabilities	6,307	11,406
Accrued income taxes	967
Operating lease liabilities	435	246
Deferred revenue	3,208	3,208
Total current liabilities	20,802	17,226
Non-current liabilities:
Operating lease liabilities, net of current portion	23,548	23,688
Deferred revenue, net of current portion	354	1,156
Total liabilities	44,704	42,070
Commitments and contingencies (Note 8)
Stockholders’ equity:
Preferred stock, $0.0001 par value, 10,000,000 shares authorized; no shares issued and outstanding at March 31, 2022 and December 31, 2021
Common stock, $0.0001 par value; 200,000,000 shares authorized; 57,385,578 and 57,150,274 shares issued and outstanding as of March 31, 2022 and December 31, 2021, respectively	6	6
Additional paid-in capital	598,275	593,784
Accumulated other comprehensive loss		(7)
Accumulated deficit	(332,027)	(424,132)
Total stockholders’ equity	266,254	169,651
Total liabilities and stockholders' equity	$ 310,958	$ 211,721