CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Revenues:
Total revenues	$ 7,323	$ 7,489
Operating expenses:
Cost of sales, excluding amortization of acquired intangible assets	1,390	980
Research and development	5,479	4,853
Sales and marketing	5,659	8,125
General and administrative	5,115	4,360
Amortization of acquired intangible assets	615	615
Total operating expenses	18,258	18,933
Loss from operations	(10,935)	(11,444)
Other income (expense):
Interest and other income, net	1	54
Interest expense	(1,346)	(1,784)
Total other expense, net	(1,345)	(1,730)
Net loss	$ (12,280)	$ (13,174)
Net loss per share - basic and diluted	$ (0.50)	$ (1.14)
Weighted average shares outstanding - basic and diluted	24,735	11,553
Net loss	$ (12,280)	$ (13,174)
Comprehensive loss	(12,280)	(13,174)
Product [Member]
Revenues:
Total revenues	6,802	4,687
License and Collaboration Agreement [Member]
Revenues:
Total revenues	341	2,020
Royalty Income [Member]
Revenues:
Total revenues	$ 180	$ 782