Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 249,471	$ 342,027
Investments	417,727	312,001
Collaboration receivables	24,030	26,598
Prepaid expenses and other current assets	20,958	11,741
Restricted cash	4,826	4,826
Total current assets	717,012	697,193
Property and equipment, net	18,249	15,372
Right-of-use assets, net	68,123	72,957
Goodwill	21,359	21,359
Intangible assets, net	74,507	79,127
Other assets	5,620	3,928
Total assets	904,870	889,936
Current liabilities:
Accounts payable	13,736	8,839
Accrued expenses	15,079	13,202
Current portion of deferred revenue	41,014	67,563
Current portion of operating lease liability	11,685	11,733
Total current liabilities	81,514	101,337
Contingent consideration	112,493	152,230
Deferred revenue, net of current portion	252,055	228,659
Operating lease liability, net of current portion	46,171	50,953
Total liabilities	492,233	533,179
Commitments and contingencies (Notes 3 and 12)
Stockholders' equity:
Preferred stock, $0.001 par value; 10,000,000 shares authorized as of June 30, 2021 and December 31, 2020; no shares issued and outstanding as of June 30, 2021 and December 31, 2020	0
Common stock, $0.001 par value; 200,000,000 shares authorized as of June 30, 2021 and December 31, 2020; 75,343,712 shares and 75,029,625 shares issued and outstanding as of June 30, 2021 and December 31, 2020, respectively	75	75
Additional paid-in capital	782,144	769,965
Accumulated deficit	(369,617)	(413,283)
Accumulated other comprehensive income	35
Total stockholders' equity	412,637	356,757
Total liabilities and stockholders' equity	$ 904,870	$ 889,936