Quarterly report pursuant to Section 13 or 15(d)

Shareholders' Equity / (Deficit) - Additional Information (Details)

v3.21.1
Shareholders' Equity / (Deficit) - Additional Information (Details)
$ / shares in Units, $ in Thousands
1 Months Ended 2 Months Ended 3 Months Ended 12 Months Ended
Feb. 12, 2021
$ / shares
shares
Feb. 10, 2021
USD ($)
$ / shares
shares
Feb. 09, 2021
USD ($)
$ / shares
shares
Feb. 08, 2021
$ / shares
shares
Feb. 03, 2021
$ / shares
shares
Oct. 31, 2020
$ / shares
shares
Oct. 27, 2020
USD ($)
$ / shares
shares
Jul. 02, 2020
$ / shares
shares
Jun. 05, 2020
$ / shares
shares
Jun. 03, 2020
USD ($)
$ / shares
shares
Jun. 30, 2020
USD ($)
$ / shares
shares
Mar. 31, 2021
USD ($)
$ / shares
shares
Mar. 31, 2021
USD ($)
Vote
$ / shares
shares
Dec. 31, 2020
USD ($)
$ / shares
shares
Jan. 28, 2021
$ / shares
shares
Jun. 10, 2020
$ / shares
shares
Apr. 27, 2018
$ / shares
shares
Class Of Stock [Line Items]                                  
Ordinary shares, shares issued                       179,137,432 179,137,432 49,431,028      
Ordinary shares, par value | $ / shares                       $ 0.01 $ 0.01 $ 0.01 $ 0.01 $ 0.01  
Ordinary shares, shares authorized                       300,000,000 300,000,000 150,000,000 150,000,000 100,000,000  
Number of vote per common share | Vote                         1        
Common stock rights and preferences                         The holders of ordinary shares have no preemptive or other subscription rights, and there are no redemption or sinking fund provisions with respect to such shares        
Undesignated preferred shares, par value | $ / shares                       $ 0.01 $ 0.01 $ 0.01      
Undesignated preferred shares, authorized                       100,000,000 100,000,000 100,000,000      
Undesignated preferred shares issued                       0 0 0      
Undesignated Preferred Shares                                  
Class Of Stock [Line Items]                                  
Undesignated preferred shares, par value | $ / shares                       $ 0.01 $ 0.01        
Undesignated preferred shares, authorized                       100,000,000 100,000,000        
Designated Preferred Shares                                  
Class Of Stock [Line Items]                                  
Undesignated preferred shares issued                       0 0 0      
Silicon Valley Bank and Life Sciences Fund II LLC | Series B Convertible Preferred Shares                                  
Class Of Stock [Line Items]                                  
Number of warrants to purchase ordinary shares                       19,890 19,890       19,890
Warrants to purchase ordinary shares, exercise price | $ / shares                       $ 18.85 $ 18.85       $ 18.85
Exchangeable Notes                                  
Class Of Stock [Line Items]                                  
Ordinary shares, shares issued                       51,499,567 51,499,567        
Aggregate principal amount of exchangeable notes | $                       $ 37,500          
Aggregate principal amount | $                       $ 14,300 $ 14,300        
Ordinary Shares                                  
Class Of Stock [Line Items]                                  
Number of warrants to purchase ordinary shares                       19,890 19,890       19,890
June 3 SPA                                  
Class Of Stock [Line Items]                                  
Ordinary shares, par value | $ / shares                       $ 0.01 $ 0.01        
February Registered Direct Offering                                  
Class Of Stock [Line Items]                                  
Ordinary shares, shares issued     17,500,000                            
Ordinary shares, par value | $ / shares     $ 0.01                            
Offering price per share | $ / shares     $ 2.00                            
Aggregate gross proceeds from ordinary shares | $     $ 35,000                            
Proceeds from registered direct offerings, net of transaction costs | $     $ 32,200                            
Offering closing date     Feb. 12, 2021                            
June 3 Offering | June 3 SPA                                  
Class Of Stock [Line Items]                                  
Ordinary shares, shares issued                   2,971,770              
Ordinary shares, par value | $ / shares                   $ 0.01              
Offering price per share | $ / shares                   $ 1.6825              
Aggregate gross proceeds from ordinary shares | $                   $ 5,000              
Proceeds from registered direct offerings, net of transaction costs | $                   $ 4,300              
Warrants closing date                   Jun. 05, 2020              
June 30 Offering | June 30 SPA                                  
Class Of Stock [Line Items]                                  
Ordinary shares, shares issued                     3,372,686            
Ordinary shares, par value | $ / shares                     $ 0.01            
Offering price per share | $ / shares                     $ 1.4825            
Aggregate gross proceeds from ordinary shares | $                     $ 5,000            
Proceeds from registered direct offerings, net of transaction costs | $                     $ 4,200            
Warrants closing date                     Jul. 02, 2020            
October Offering                                  
Class Of Stock [Line Items]                                  
Ordinary shares, shares issued             15,511,537                    
Ordinary shares, par value | $ / shares             $ 0.01         $ 0.01 $ 0.01        
Aggregate gross proceeds from ordinary shares | $             $ 17,400                    
Proceeds from registered direct offerings, net of transaction costs | $             $ 15,500           $ 13,400        
Number of warrants to purchase ordinary shares           1,884,615           20,232,439 20,232,439        
Warrants to purchase ordinary shares, exercise price | $ / shares           $ 0.8125 $ 0.65                    
Warrants expiry date           Oct. 22, 2025 Oct. 27, 2025                    
Percentage of ordinary shares issued to purchase warrants           7.00%                      
October Offering | Maximum                                  
Class Of Stock [Line Items]                                  
Number of warrants to purchase ordinary shares             20,192,307                    
October Offering | Pre-Funded Warrants                                  
Class Of Stock [Line Items]                                  
Offering price per share | $ / shares             $ 0.01                    
Proceeds from registered direct offerings, net of transaction costs | $                           $ 110      
Number of warrants to purchase ordinary shares             11,411,539                    
Warrants to purchase ordinary shares, exercise price | $ / shares             $ 0.64                    
October Offering | Warrant                                  
Class Of Stock [Line Items]                                  
Offering price per share | $ / shares             $ 0.65                    
Number of warrants to purchase ordinary shares             20,192,307                    
Warrants to purchase ordinary shares, exercise price | $ / shares             $ 0.65                    
February Underwritten Offering                                  
Class Of Stock [Line Items]                                  
Warrants to purchase ordinary shares, exercise price | $ / shares   $ 1.4375   $ 1.4375                          
Offering closing date   Feb. 10, 2021   Feb. 08, 2021                          
Additional ordinary shares that can be purchased by underwriter   5,217,391                              
Warrants expiry date   Feb. 03, 2026   Feb. 03, 2026                          
Percentage of ordinary shares issued to purchase warrants   7.00%   7.00%                          
February Underwritten Offering | Maximum                                  
Class Of Stock [Line Items]                                  
Number of warrants to purchase ordinary shares   365,217   2,434,783                          
February Underwritten Offering | Underwriting Agreement                                  
Class Of Stock [Line Items]                                  
Ordinary shares, shares issued         34,782,609                        
Ordinary shares, par value | $ / shares         $ 0.01                        
Offering price per share | $ / shares         $ 1.15                        
Offering closing date         Feb. 08, 2021                        
February Underwritten Offering | Pursuant to the Underwriting Agreement                                  
Class Of Stock [Line Items]                                  
Ordinary shares, shares issued   40,000,000                              
Aggregate gross proceeds from ordinary shares | $   $ 46,000                              
Proceeds from registered direct offerings, net of transaction costs | $   $ 42,100                              
Additional ordinary shares that can be purchased by underwriter   5,217,391                              
Percentage of ordinary shares issued to purchase warrants   7.00%                              
February Underwritten Offering | Pursuant to the Underwriting Agreement | Warrant                                  
Class Of Stock [Line Items]                                  
Number of warrants to purchase ordinary shares   2,800,000                              
Warrants to purchase ordinary shares, exercise price | $ / shares   $ 1.4375                              
Private Placement | Securities Purchase Agreement                                  
Class Of Stock [Line Items]                                  
Number of warrants to purchase ordinary shares                 208,023                
Warrants to purchase ordinary shares, exercise price | $ / shares                 $ 2.1031 $ 1.62              
Warrants expiry date                 Jun. 03, 2025 Dec. 05, 2025              
Percentage of ordinary shares issued to purchase warrants                 7.00%                
Private Placement | Securities Purchase Agreement | Maximum                                  
Class Of Stock [Line Items]                                  
Number of warrants to purchase ordinary shares                   1,485,885              
Private Placement | June 30 SPA                                  
Class Of Stock [Line Items]                                  
Proceeds from registered direct offerings, net of transaction costs | $                         $ 1,800        
Number of warrants to purchase ordinary shares               236,088       1,264,757 1,264,757        
Warrants to purchase ordinary shares, exercise price | $ / shares               $ 1.8531     $ 1.42            
Warrants expiry date               Jun. 30, 2025     Jan. 02, 2026            
Percentage of ordinary shares issued to purchase warrants               7.00%                  
Private Placement | June 30 SPA | Maximum                                  
Class Of Stock [Line Items]                                  
Number of warrants to purchase ordinary shares                     1,686,343            
Private Placement | Exchangeable Notes                                  
Class Of Stock [Line Items]                                  
Aggregate principal amount of exchangeable notes | $                       $ 37,500          
Private Placement | June 3 SPA                                  
Class Of Stock [Line Items]                                  
Warrants closing date                   Jun. 05, 2020              
Number of warrants to purchase ordinary shares                 208,023                
Warrants to purchase ordinary shares, exercise price | $ / shares                 $ 2.1031 $ 1.62              
Warrants expiry date                 Jun. 03, 2025 Dec. 05, 2025              
Percentage of ordinary shares issued to purchase warrants                 7.00%                
Private Placement | June 3 SPA | Maximum                                  
Class Of Stock [Line Items]                                  
Number of warrants to purchase ordinary shares                   1,485,885              
February Registered Direct Offering                                  
Class Of Stock [Line Items]                                  
Warrants to purchase ordinary shares, exercise price | $ / shares $ 2.50                                
Offering closing date Feb. 12, 2021                                
Warrants expiry date Feb. 09, 2026                                
Percentage of ordinary shares issued to purchase warrants 7.00%                                
February Registered Direct Offering | Maximum                                  
Class Of Stock [Line Items]                                  
Number of warrants to purchase ordinary shares 1,225,000