Condensed Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 19,249	$ 15,960
Short-term investments	85,849	98,103
Restricted cash	918	1,256
Prepaid expenses	9,272	8,159
Contract and other receivables	61	10,021
Other current assets	410	759
Total current assets	115,759	134,258
Property and equipment, net	10,956	5,400
Intangibles, net	1,069	1,081
Other assets	354	344
Total assets	128,138	141,083
Current liabilities:
Accounts payable	3,622	2,717
Accrued liabilities	5,456	6,329
Accrued compensation	1,211	2,392
Current portion of deferred revenue	723	1,194
Total current liabilities	11,012	12,632
Deferred revenue, less current portion	2,047	2,065
Other long-term liabilities	7,850	2,308
Total liabilities	$ 20,909	$ 17,005
Commitments and Contingencies
Stockholders’ equity:
Common stock, $0.001 par value; 200,000,000 shares authorized, 52,774,550 and 52,669,266 shares issued and outstanding at March 31, 2016 (unaudited) and December 31, 2015, respectively	$ 53	$ 53
Additional paid-in capital	319,990	315,673
Accumulated other comprehensive loss	(92)	(133)
Accumulated deficit	(212,722)	(191,515)
Total stockholders’ equity	107,229	124,078
Total liabilities and stockholders’ equity	$ 128,138	$ 141,083