Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Current assets
Cash and cash equivalents	$ 99,495	$ 112,265
Prepaid expenses and other current assets	1,245	1,282
Total current assets	100,740	113,547
Property and equipment, net	3,007	2,744
Other long term assets	289	289
Total assets	104,036	116,580
Current liabilities
Accounts payable	1,994	2,143
Accrued liabilities	4,827	5,633
Deferred revenue	10,649	14,199
Total current liabilities	17,470	21,975
Other long-term liabilities	658	732
Total liabilities	$ 18,128	$ 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 March 31, 2016 and December 31, 2015; 27,016,082 and 27,053,156 shares, issued and outstanding at March 31, 2016 and December 31, 2015, respectively	$ 3	$ 3
Additional paid-in-capital	159,010	158,555
Accumulated deficit	(73,105)	(64,685)
Total stockholders’ equity	85,908	93,873
Total liabilities and stockholders’ equity	$ 104,036	$ 116,580