v3.21.1
Summary of significant accounting policies - Sources of Liquidity and Funding Requirements (Details) - USD ($)
$ in Thousands
1 Months Ended
Apr. 30, 2019
Oct. 31, 2020
Jul. 31, 2020
May 31, 2019
Mar. 31, 2021
Dec. 31, 2020
Summary of significant accounting policies            
Net proceeds from convertible preferred shares to accredited investors $ 138,800          
Net proceeds from issuance of common shares in Initial Public Offering       $ 85,400    
Net proceeds from issuance of pre-funded warrants in a private placement     $ 24,800      
Net proceeds from offering of common shares and pre-funded warrants   $ 48,200        
Cash, cash equivalents and short-term investments         $ 129,900  
Accumulated deficit         $ (175,980) $ (163,466)