Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 27,986	$ 69,482
Marketable securities	117,595	139,518
Interest receivable	310	307
Accounts receivable	1,482	2,521
Prepaid expenses	1,472	754
Total current assets	148,845	212,582
Marketable securities, non-current	9,507
Property and equipment, net	4,882	2,916
Goodwill	1,585	1,585
Other assets	159	152
Total assets	164,978	217,235
Current liabilities:
Accounts payable and accrued liabilities	6,317	8,229
Accrued compensation and employee benefits	2,837	2,748
Deferred revenues	4,714	9,120
Total current liabilities	13,868	20,097
Deferred revenues, non-current	5,018	4,699
Build-to-suit lease obligation	2,256
Total liabilities	21,142	24,796
Commitments and contingencies
Stockholders' equity:
Common stock, $0.01 par value; 160,000,000 shares authorized, 70,621,837 and 70,354,608 shares issued and outstanding at September 30, 2016 and December 31, 2015, respectively	706	703
Additional paid-in capital	574,340	560,989
Accumulated deficit	(431,287)	(369,253)
Accumulated other comprehensive income	77
Total stockholders' equity	143,836	192,439
Total liabilities and stockholders' equity	$ 164,978	$ 217,235