Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 59,624	$ 126,310
Marketable securities	153,978	140,129
Accounts receivable	342	12,037
Prepaid expenses and other current assets	3,958	4,500
Total current assets	217,902	282,976
Marketable securities		11,434
Property and equipment, net	24,688	29,157
Operating lease right-of-use assets	21,110
Goodwill	8,167	8,334
Intangible assets, net	18,978	25,135
Restricted cash	468	468
Total assets	291,313	357,504
Current liabilities:
Accounts payable	414	1,457
Accrued clinical trial and manufacturing expenses	4,253	2,542
Accrued expenses and other liabilities	8,181	10,518
Operating lease liabilities	1,803
Deferred revenue	6,950	16,000
Total current liabilities	21,601	30,517
Deferred rent		11,063
Contingent consideration	1,051	998
Deferred revenue	166,963	172,671
Deferred tax liabilities	3,527	6,104
Operating lease liabilities	31,636
Other long-term liabilities	940	840
Total liabilities	225,718	222,193
Commitments and contingencies
Stockholders’ equity:
Preferred stock, $0.0001 par value; 10,000,000 shares authorized at December 31, 2019 and 2018; and no shares issued and outstanding at December 31, 2019 and 2018
Common stock, $0.0001 par value; 300,000,000 shares authorized at December 31, 2019 and 2018; 80,735,688 and 79,571,714 shares issued and outstanding at December 31, 2019 and 2018	8	8
Additional paid-in capital	552,077	538,895
Accumulated other comprehensive income	414	940
Accumulated deficit	(486,904)	(404,532)
Total stockholders’ equity	65,595	135,311
Total liabilities and stockholders’ equity	$ 291,313	$ 357,504