Condensed Consolidated Statements of Operations (Unaudited) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Revenue:
Revenue	$ 4,281	$ 3,189
Operating expenses:
Research and development	12,392	8,110
Selling, general and administrative	9,224	6,697
Change in contingent consideration liability	900	800
Total operating expenses	22,516	15,607
Operating loss	(18,235)	(12,418)
Other (expense) income:
Interest (expense) income and other income, net	(500)	(1,006)
Total other (expense) income	(500)	(1,006)
Net loss	$ (18,735)	$ (13,424)
Net loss per share - basic and diluted (in dollars per share)	$ (0.22)	$ (0.19)
Weighted-average shares - basic and diluted (in shares)	84,542	72,517
Royalty [Member]
Revenue:
Revenue	$ 4,161	$ 3,058
Product and Service, Other [Member]
Revenue:
Revenue	$ 120	$ 131

Amount of increase (decrease) in the value of a contingent consideration liability, including, but not limited to, differences arising upon settlement.

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