Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenues:
Contract revenue	$ 18,860	$ 13,304	$ 5,846
License and royalty revenue	2,090	1,913	1,872
Total revenues	20,950	15,217	7,718
Operating expenses:
Research and development	11,061	11,467	14,558
Manufacturing and production	10,927	10,824	12,698
General and administrative	8,366	9,552	11,814
Total operating expenses	30,354	31,843	39,070
Loss from operations	(9,404)	(16,626)	(31,352)
Other income:
Investment and other income, net	166	134	114
Net loss	$ (9,238)	$ (16,492)	$ (31,238)
Basic and diluted net loss per share	$ (0.10)	$ (0.19)	$ (0.36)
Weighted average shares used in computing basic and diluted net loss per share	91,751	88,786	86,840