Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 21,472	$ 24,289
Marketable securities available-for-sale	63,884	57,126
Accounts and other receivables	1,465	1,342
Prepaid expenses and other current assets	2,831	6,842
Total current assets	89,652	89,599
Property and equipment, net	16,633	17,174
Goodwill	2,001	1,971
Restricted cash	605	602
Other assets	1,241	334
Total assets	110,132	109,680
Current liabilities:
Accounts payable	1,466	3,796
Accrued research and development	4,305	5,048
Accrued liabilities	6,607	11,192
Total current liabilities	12,378	20,036
Other long-term liabilities	358	443
Total liabilities	12,736	20,479
Commitments and contingencies (Note 4)
Stockholders’ equity:
Preferred stock: $0.001 par value; 5,000 shares authorized at March 31, 2017 and December 31, 2016; no shares issued and outstanding at March 31, 2017 and December 31, 2016
Common stock: $0.001 par value; 69,500 shares authorized at March 31, 2017 and December 31, 2016; 45,448 and 38,599 shares issued and outstanding at March 31, 2017 and December 31, 2016, respectively	45	39
Additional paid-in capital	938,159	904,957
Accumulated other comprehensive loss	(3,350)	(3,624)
Accumulated deficit	(837,458)	(812,171)
Total stockholders’ equity	97,396	89,201
Total liabilities and stockholders’ equity	$ 110,132	$ 109,680