CONSOLIDATED STATEMENTS OF OPERATIONS AND COMPREHENSIVE LOSS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net revenue
Product	$ 7,833	$ 4,604	$ 2,400
Royalty and other	1,009	1,420	1,990
Total net revenue	8,842	6,024	4,390
Cost of net revenue	4,694	3,075	2,474
Gross profit	4,148	2,949	1,916
Operating expenses
Research and development	8,158	18,086	27,108
Selling, general and administrative	4,702	5,693	6,299
Impairment of goodwill		9,858
Restructuring charges	1,321	676
Total operating expenses	14,181	34,313	33,407
Loss from operations	(10,033)	(31,364)	(31,491)
Interest expense	927	687
Other income, net	59	48	94
Loss before income taxes	(10,901)	(32,003)	(31,397)
Income tax provision (benefit)	(233)	45	86
Net loss	(10,668)	(32,048)	(31,483)
Other comprehensive income (loss), net of tax:
Net unrealized gains (losses) on available-for-sale securities		16	(6)
Comprehensive loss	$ (10,668)	$ (32,032)	$ (31,489)
Net loss per share
Basic and diluted	$ (1.45)	$ (4.86)	$ (5.04)
Shares used in computing net loss per share
Basic and diluted	7,338	6,601	6,249