Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Current Assets:
Cash and cash equivalents	$ 55,819	$ 73,551
Short-term investments	44,090	136,793
Accounts receivable	2,733	2,416
Other current assets	19,466	35,036
Total Current Assets	122,108	247,796
Restricted cash and investments	11,478	782
Property and equipment, net of accumulated depreciation of $23,368 and $19,896 as of September 30, 2015 and December 31, 2014, respectively	37,379	38,501
Patent costs, net of accumulated amortization of $2,486 and $2,081 as of September 30, 2015 and December 31, 2014, respectively	6,116	5,891
Other assets	7,670	2,063
Total Assets	184,751	295,033
Current Liabilities:
Accounts payable	7,431	12,408
Accrued expenses	19,761	17,366
Current portion of long-term debt	3,435	98
Current portion of notes payable	2,454	2,492
Deferred revenue	3,303	3,318
Other current liabilities	1,283	1,185
Total Current Liabilities	37,667	36,867
Long-term debt	17,397	1,476
Notes payable		2,262
Deferred rent and other	6,451	6,775
Total Liabilities	$ 61,515	$ 47,380
Commitments and contingencies
Stockholders’ Equity:
Preferred stock, $.0001 par value, 3,333,333 shares authorized; none issued and outstanding
Common stock, $.0001 par value, 99,000,000 shares authorized; 41,963,151 and 41,311,512 issued and outstanding at September 30, 2015 and December 31, 2014, respectively	$ 4	$ 4
Additional paid-in capital	957,607	926,769
Accumulated other comprehensive loss	(1)	(95)
Accumulated deficit	(834,374)	(679,025)
Total Stockholders’ Equity	123,236	247,653
Total Liabilities and Stockholders’ Equity	$ 184,751	$ 295,033