Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 1,161	$ 2,156
Marketable securities	11,214	13,952
Inventory-work in process	1,326	0
Prepaid expenses and other current assets	278	399
Total current assets	13,979	16,507
Property and equipment, net	11,501	4,601
Patent and trademark rights, net	883	861
Construction in progress	0	7,337
Other assets	134	134
Total assets	26,497	29,440
Current liabilities:
Accounts payable	1,506	2,081
Accrued expenses	1,818	2,333
Current portion of capital lease	3	22
Total current liabilities	3,327	4,436
Commitments and contingencies (Note 6)	0	0
Stockholders’ equity:
Preferred stock, par value $0.01 per share, authorized 5,000,000; issued and outstanding; none	0	0
Common stock, par value $0.001 per share, authorized 350,000,000 shares; issued and outstanding 247,557,287 and 204,004,818, respectively	248	204
Additional paid-in capital	313,185	302,729
Accumulated other comprehensive loss	(401)	(160)
Accumulated deficit	(289,862)	(277,769)
Total stockholders’ equity	23,170	25,004
Total liabilities and stockholders’ equity	$ 26,497	$ 29,440