Condensed Consolidated Statements of Operations and Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Statement of Comprehensive Income [Abstract]
Revenue	$ 1,134	$ 734	$ 2,717	$ 1,521
Costs and operating expenses:
Cost of products sold	2,663	2,435	5,857	4,611
Research and development	8,176	5,247	16,149	9,624
Selling, general and administrative	9,125	6,927	19,360	11,020
Change in fair value of contingent consideration	635		(1,584)
Total costs and operating expenses	20,599	14,609	39,782	25,255
Loss from operations	(19,465)	(13,875)	(37,065)	(23,734)
Other income (expense):
Change in fair value of warrant liability and embedded derivative	(2,453)	(1,446)	(1,872)	(605)
Loss on debt extinguishment		(1,398)		(1,398)
Interest income	95	143	370	208
Interest expense	(1,370)	(13,769)	(2,724)	(19,511)
Total other expense, net	(3,728)	(16,470)	(4,226)	(21,306)
Net loss	(23,193)	(30,345)	(41,291)	(45,040)
Other comprehensive income (loss)
Unrealized (loss) gain on marketable securities	(14)	6	(41)	7
Foreign currency translation adjustment	96	2	69	(12)
Comprehensive loss	$ (23,111)	$ (30,337)	$ (41,263)	$ (45,045)
Net loss per common share, basic and diluted	$ (32.24)	$ (45.70)	$ (58.16)	$ (68.21)
Weighted-average shares outstanding, basic and diluted	719,421	663,972	709,961	660,333