Condensed Consolidated Statements of Operations and Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Revenues:
Total revenues	$ 370	$ 589	$ 1,020	$ 2,598
Operating expenses:
Research and development	1,334	1,749	4,524	5,241
Selling, general and administrative	3,011	2,415	8,581	8,410
Total operating expenses	4,469	4,204	13,536	13,913
Loss from operations	(4,099)	(3,615)	(12,516)	(11,315)
Interest expense		(43)		(747)
Other income, net	134	46	266	246
Initial loss on common stock warrant and common stock adjustment feature liability			(4,000)
Change in fair value of common stock warrant liabilities and common stock adjustment feature liability	8,421		5,986
Offering costs	(1)		(2,544)
Loss on extinguishing of debt		(900)		(900)
Net income (loss) before income taxes	4,455	(4,512)	(12,808)	(12,716)
Income tax provision	(5)	(13)	(26)	(31)
Net income (loss)	$ 4,450	$ (4,525)	$ (12,834)	$ (12,747)
Net income (loss) per share attributable to common stockholders:
Basic and diluted	$ 0.93	$ (2.12)	$ (3.74)	$ (5.89)
Weighted-average number of shares used in per share calculations:
Basic and diluted	4,774,732	2,133,846	3,427,799	2,163,604
Other comprehensive income (loss), net of tax
Unrealized losses (gains) on available-for-sale securities	$ (2)	$ 8	$ (1)	$ 14
Other comprehensive loss (income)	(2)	8	(1)	14
Comprehensive income (loss) attributable to common stockholders	4,448	(4,517)	(12,835)	(12,733)
Product
Revenues:
Total revenues	144	82	393	482
Operating expenses:
Cost of product revenues	124	40	431	262
License
Revenues:
Total revenues	10	144	100	353
Contract Research And Government Grants
Revenues:
Total revenues	$ 216	$ 363	$ 527	$ 1,763