Statements of Operations - USD ($)
shares in Thousands, $ in Thousands
 12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Revenues:      
Contract revenue $ 12,804 $ 18,860 $ 13,304
License and royalty revenue 1,727 2,090 1,913
Total revenues 14,531 20,950 15,217
Operating expenses:      
Research and development 10,355 11,061 11,467
Manufacturing and production 6,291 10,927 10,824
General and administrative 7,062 8,366 9,552
Total operating expenses 23,708 30,354 31,843
Loss from operations (9,177) (9,404) (16,626)
Other income:      
Investment and other income, net 204 166 134
Net loss $ (8,973) $ (9,238) $ (16,492)
Basic and diluted net loss per share $ (0.90) $ (1.01) $ (1.86)
Weighted average shares used in computing basic and diluted net loss per share 10,019 9,175 8,879