Condensed Consolidated Statements of Operations and Comprehensive Loss (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Revenues:
Product	$ 205	$ 255
License	106	152
Contract research and government grants	707	445
Total revenues	1,018	852
Operating expenses:
Cost of product revenues	106	147
Research and development	1,823	2,202
Selling, general and administrative	3,052	3,436
Total operating expenses	4,981	5,785
Loss from operations	(3,963)	(4,933)
Interest expense	(339)	(327)
Other income, net	96	76
Net loss before income taxes	(4,206)	(5,184)
Income tax provision	(10)	(6)
Net loss and net loss attributable to common stockholders	$ (4,216)	$ (5,190)
Net loss per share attributable to common stockholders:
Basic and diluted	$ (0.10)	$ (0.12)
Weighted-average number of shares used in per share calculations:
Basic and diluted	44,360,189	44,215,156
Other comprehensive income (loss), net of tax
Unrealized gains (losses) on available-for-sale securities	$ (1)	$ 84
Other comprehensive income (loss)	(1)	84
Comprehensive loss attributable to common stockholders	$ (4,217)	$ (5,106)