Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 74,932	$ 150,456
Short-term marketable securities	272,500	265,198
Accounts receivable	1,138	4,846
Prepaid expenses and other current assets	6,194	4,004
Total current assets	354,764	424,504
Long-term marketable securities	14,474	15,391
Property and equipment, net	26,384	3,986
Goodwill	7,658	8,469
Intangible assets, net	27,827	29,400
Restricted cash	468
Deferred tax assets	6,319
Other assets	717	75
Total assets	438,611	481,825
Current liabilities:
Accounts payable	2,206	5,086
Accrued clinical trial and manufacturing expenses	4,777	5,522
Accrued expenses and other liabilities	8,597	5,412
Deferred revenue	15,052	15,046
Total current liabilities	30,632	31,066
Deferred rent	6,786
Contingent consideration	4,032	3,750
Deferred revenue	162,963	178,037
Deferred tax liabilities	5,869	7,350
Other long term liabilities	1,109
Total liabilities	211,391	220,203
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.0001 par value; 10,000,000 shares authorized at December 31, 2016 and 2015; and no shares issued and outstanding at December 31, 2016 and 2015
Common stock, $0.0001 par value; 300,000,000 shares authorized at December 31, 2016 and 2015; and 67,918,246 and 63,587,833 shares issued and outstanding at December 31, 2016 and 2015	7	6
Additional paid-in capital	420,897	362,807
Accumulated other comprehensive loss	(1,684)	(339)
Accumulated deficit	(192,000)	(100,852)
Total stockholders’ equity	227,220	261,622
Total liabilities and stockholders’ equity	$ 438,611	$ 481,825