Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 53,605	$ 126,310
Short-term marketable securities	178,182	140,129
Accounts receivable	222	12,037
Prepaid expenses and other current assets	3,805	4,500
Total current assets	235,814	282,976
Long-term marketable securities	3,593	11,434
Property and equipment, net	25,534	29,157
Operating lease right-of-use assets	21,346
Goodwill	7,949	8,334
Intangible assets, net	18,608	25,135
Restricted cash	468	468
Total assets	313,312	357,504
Current liabilities:
Accounts payable	1,643	1,457
Accrued clinical trial and manufacturing expenses	4,012	2,542
Accrued expenses and other liabilities	9,125	10,518
Operating lease liabilities	1,700
Deferred revenue	16,000	16,000
Total current liabilities	32,480	30,517
Deferred rent		11,063
Contingent consideration	975	998
Deferred revenue	161,203	172,671
Deferred tax liabilities	3,522	6,104
Operating lease liabilities	32,120
Other long-term liabilities	966	840
Total liabilities	231,266	222,193
Commitments and contingencies (Note 7)
Stockholders’ equity:
Preferred stock, $0.0001 par value; 10,000,000 shares authorized; no shares issued and outstanding at September 30, 2019 and December 31, 2018
Common stock, $0.0001 par value; 300,000,000 shares authorized; 80,514,459 and 79,571,714 shares issued and outstanding at September 30, 2019 and December 31, 2018	8	8
Additional paid-in capital	549,705	538,895
Accumulated other comprehensive (loss) income	(178)	940
Accumulated deficit	(467,489)	(404,532)
Total stockholders’ equity	82,046	135,311
Total liabilities and stockholders’ equity	$ 313,312	$ 357,504