License and Other Agreements - Amendment to License Agreement with Yale (Details) - Yale Agreement - Collaborative arrangement - USD ($) $ in Thousands	1 Months Ended
	May 31, 2019	Sep. 30, 2013
License and other agreements
Common stock issued (shares)		250,000
Right to purchase securities in specified future equity offering (as a percent)		10.00%
Milestone payment to be paid upon regulatory achievement	$ 2,000
Minimum annual royalty payment to be paid upon sale of product	$ 1,000
Notice period to terminate agreement	90 days
Expiration period based on country by country basis after first commercial sale (in years)	10 years
Maximum
License and other agreements
Extension of due diligence requirements (in years)	1 year
Amount of payment subject to due diligence extension	$ 150