Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenue:
Total revenue	$ 34	$ 194	$ 99	$ 495
Costs and expenses:
Cost of goods sold		24	4	321
Research and development	2,474	2,007	7,484	6,392
Selling, general and administrative	1,408	1,390	4,642	4,460
Total costs and expenses	3,882	3,421	12,130	11,173
Operating loss	(3,848)	(3,227)	(12,031)	(10,678)
Other income (expense):
Interest income	1	17	19	53
Gain on change in fair value of redemption feature embedded in convertible notes		52		52
Interest expense	(1)	(112)	(2)	(112)
Loss on extinguishment of convertible notes		(521)		(521)
Other expense		(1)	(1)	(2)
Total other (expense) income		(565)	16	(530)
Net loss	$ (3,848)	$ (3,792)	$ (12,015)	$ (11,208)
Net loss per share, basic and diluted (in dollars per share)	$ (0.30)	$ (0.63)	$ (1.33)	$ (2.13)
Weighted-average shares used in computing net loss per share, basic and diluted (in shares)	12,618,285	6,030,662	9,059,433	5,263,058
Product [Member]
Revenue:
Total revenue	$ 8	$ 1	$ 13	$ 139
Collaboration Agreement [Member]
Revenue:
Total revenue	$ 26	$ 193	$ 86	$ 356