Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Revenues:
Revenues	$ 1,611	$ 1,026
Operating expenses:
Research and development	6,852	5,404
General and administrative	2,455	2,610
Settlement costs (Note 9)		42
Operating expenses, total	9,307	8,056
Loss from operations	(7,696)	(7,030)
Other income (expense), net:
Interest expense, net	(564)	(493)
Change in fair value of PIPE Warrant liability	8,815	(1,465)
Other income (expense), net	8,251	(1,958)
Net income (loss)	$ 555	$ (8,988)
Basic net income (loss) per share
Net income (loss) per share	$ 0.01	$ (0.08)
Weighted average number of common shares outstanding	132,304	118,840
Diluted net income (loss) per share
Net income (loss) per share	$ (0.06)	$ (0.08)
Weighted average number of common shares and dilutive common share equivalents outstanding	132,831	118,840
Collaboration and Licensing Revenue
Revenues:
Revenues	$ 1,454	$ 980
Partnership Royalties
Revenues:
Revenues	$ 157	$ 46