Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Current assets
Cash and cash equivalents	$ 77,120	$ 112,265
Prepaid expenses and other current assets	762	1,282
Total current assets	77,882	113,547
Property and equipment, net	2,729	2,744
Other long-term assets	750	289
Total assets	81,361	116,580
Current liabilities
Accounts payable	1,731	2,143
Accrued liabilities	6,930	5,633
Deferred revenue	3,550	14,199
Total current liabilities	12,211	21,975
Other long-term liabilities	503	732
Total liabilities	12,714	22,707
Commitments and contingencies (Note 6)
Stockholders’ equity (deficit)
Preferred stock, $0.0001 par value; 5,000,000 shares authorized; none issued and outstanding
Common stock, $0.0001 par value, 150,000,000 shares authorized at September 30, 2016 and December 31, 2015; 27,031,114 and 27,053,156 shares, issued and outstanding at September 30, 2016 and December 31, 2015, respectively	3	3
Additional paid-in-capital	160,740	158,555
Accumulated deficit	(92,096)	(64,685)
Total stockholders’ equity	68,647	93,873
Total liabilities and stockholders’ equity	$ 81,361	$ 116,580