Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 206,510	$ 294,233
Marketable securities	1,307,197	1,448,063
Prepaid expenses and other current assets	41,455	39,841
Collaboration receivable - related party	23,722	18,506
Total current assets	1,578,884	1,800,643
Property and equipment, net	2,938	3,016
Restricted cash	1,269	1,269
Right-of-use operating asset	13,379	16,109
Other long-term assets	4,907	4,251
Total assets	1,601,377	1,825,288
Current liabilities:
Accounts payable	5,410	10,450
Accrued expenses	76,268	67,275
Operating lease liability, current portion	7,563	7,468
Total current liabilities	89,241	85,193
Operating lease liability, net of current portion	7,800	10,964
Other liabilities	100	100
Total liabilities	97,141	96,257
Commitments and contingencies (Note 5)
Stockholders’ equity:
Preferred stock, $0.0001 par value per share; 5,000,000 shares authorized at June 30, 2022 and December 31, 2021; no shares issued or outstanding at June 30, 2022 and December 31, 2021
Common stock, $0.0001 par value per share; 120,000,000 shares authorized at June 30, 2022 and December 31, 2021; 59,391,762 and 58,940,083 shares issued at June 30, 2022 and December 31, 2021; 59,388,729 and 58,937,050 shares outstanding at June 30, 2022 and December 31, 2021	6	6
Treasury stock, at cost, 3,033 shares at June 30, 2022 and December 31, 2021	(400)	(400)
Additional paid-in capital	3,262,203	3,227,471
Accumulated deficit	(1,743,701)	(1,495,386)
Accumulated other comprehensive loss	(13,872)	(2,660)
Total stockholders’ equity	1,504,236	1,729,031
Total liabilities and stockholders’ equity	$ 1,601,377	$ 1,825,288