Selected Balance Sheet Information - Schedule of accrued expenses (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Selected Balance Sheet Information
Accrued clinical consulting services	$ 660	$ 684
Accrued vendor payments	309	456
Accrued manufacturing costs	18	635
Other accrued expenses	1	1
Total	$ 988	$ 1,776