Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 15,101	$ 52,663
Marketable securities	91,640
Income tax receivable	384	200
Interest receivable	80
Prepaid expenses	1,729	287
Total current assets	108,934	53,150
Property and equipment, net	1,263	2,084
Restricted cash	700	700
Total assets	110,897	55,934
Current liabilities:
Accounts payable and accrued expenses	5,268	1,946
Deferred Revenue		1,452
Total current liabilities	5,268	3,398
Deferred lease obligation	$ 585	$ 874
Commitments and contingencies (Note 21)
Stockholders' equity:
Preferred stock; $0.001 par value; 5,000,000 shares authorized at December 31, 2015 and December 31, 2014; zero shares issued and outstanding at December 31, 2015 and December 31, 2014
Common stock; $0.001 par value; 100,000,000 shares authorized at December 31, 2015 and December 31, 2014; 27,254,863 shares and 22,802,039 shares issued and outstanding at December 31, 2015 and December 31, 2014, respectively	$ 27	$ 23
Additional paid-in capital	209,943	131,840
Accumulated deficit	(104,891)	(80,201)
Accumulated other comprehensive loss	(35)	0
Total stockholders' equity	105,044	51,662
Total liabilities and stockholders' equity	$ 110,897	$ 55,934