Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Revenue:
Total revenue	$ 38	$ 216
Costs and expenses:
Cost of goods sold	4	106
Research and development	2,786	2,166
Selling, general and administrative	1,857	1,631
Total costs and expenses	4,647	3,903
Operating loss	(4,609)	(3,687)
Other income (expense):
Interest income	16	23
Other expense	(1)	(1)
Total other income (expense), net	15	22
Net loss	$ (4,594)	$ (3,665)
Net loss per share, basic and diluted (in dollars per share)	$ (0.67)	$ (0.86)
Weighted-average shares used in computing net loss per share, basic and diluted (in shares)	6,831,976	4,248,450
Product [Member]
Revenue:
Total revenue	$ 5	$ 76
Collaboration Agreement [Member]
Revenue:
Total revenue	$ 33	$ 140