Annual report pursuant to Section 13 and 15(d)

Shareholder's Equity - Additional Information (Details)

v3.19.1
Shareholder's Equity - Additional Information (Details)
$ / shares in Units, € in Thousands, $ in Thousands
12 Months Ended
Feb. 16, 2018
USD ($)
$ / shares
shares
May 18, 2017
USD ($)
$ / shares
shares
Dec. 16, 2016
USD ($)
$ / shares
shares
Nov. 18, 2015
USD ($)
$ / shares
shares
Dec. 31, 2018
Vote
$ / shares
shares
Dec. 14, 2018
USD ($)
shares
Dec. 14, 2018
EUR (€)
shares
May 30, 2018
$ / shares
shares
May 29, 2018
shares
May 15, 2018
$ / shares
Mar. 13, 2018
$ / shares
shares
Mar. 12, 2018
$ / shares
Feb. 15, 2018
shares
Dec. 31, 2017
$ / shares
shares
Dec. 09, 2016
$ / shares
shares
Oct. 14, 2015
$ / shares
shares
Class Of Stock [Line Items]                                
Ordinary shares, shares authorized 44,557,606 7,956,715   3,659,453 50,000,000     50,000,000     44,557,606     7,956,715   413,110
Ordinary shares, shares issued         14,352,046           413,110     413,110   413,110
Ordinary shares, par value | $ / shares $ 0.01 $ 0.01   $ 0.01 $ 0.01     $ 0.01     $ 0.001 $ 0.0001   $ 0.01   $ 0.01
Share consolidation basis nominal value per share | $ / shares                   $ 0.01571            
Share consolidation basis, Renominalisation value per share | $ / shares                   0.01            
Increase in common stock, shares authorized                 5,442,394       36,600,891      
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                      
Preferred stock, conversion basis         one-for-one                      
Undesignated Preferred Shares                                
Class Of Stock [Line Items]                                
Undesignated preferred shares, par value | $ / shares               $ 0.01                
Undesignated preferred shares, authorized               100,000,000                
Undesignated preferred shares in issue         0                      
Series A Convertible Preferred Shares                                
Class Of Stock [Line Items]                                
Share consolidation basis nominal value per share | $ / shares                   0.01571            
Share consolidation basis, Renominalisation value per share | $ / shares                   0.01            
Temporary equity, shares authorized       3,022,915 0           3,032,463     3,032,463 9,548  
Temporary equity, par value | $ / shares       $ 0.01 $ 0.01           $ 0.001 0.0001   $ 0.01 $ 0.01  
Temporary equity, shares issued     1,518,137 1,514,320 0           3,032,457     3,032,457    
Temporary equity shares price per share | $ / shares     $ 15.71 $ 15.71                        
Gross cash proceeds from Issuance of convertible preferred stock | $     $ 20,851 $ 20,701                        
Series A Convertible Preferred Shares | Founders                                
Class Of Stock [Line Items]                                
Conversion of debt amount | $       $ 90                        
Convertible preferred stock issued upon conversion       5,728                        
Series A Convertible Preferred Shares | Pfizer License Agreement                                
Class Of Stock [Line Items]                                
Temporary equity, shares issued       190,961                        
Temporary equity, additional shares issued     190,961                          
Series B-1 Convertible Preferred Shares                                
Class Of Stock [Line Items]                                
Share consolidation basis nominal value per share | $ / shares                   0.01571            
Share consolidation basis, Renominalisation value per share | $ / shares                   $ 0.01            
Temporary equity, shares authorized   2,654,215                            
Temporary equity, par value | $ / shares   $ 0.01                            
Temporary equity, shares issued   2,654,206                            
Temporary equity shares price per share | $ / shares   $ 17.28                            
Gross cash proceeds from Issuance of convertible preferred stock | $   $ 45,867                            
Series B-2 Convertible Preferred Shares                                
Class Of Stock [Line Items]                                
Temporary equity, shares authorized 2,147,278 1,042,728                            
Temporary equity, par value | $ / shares $ 0.01 $ 0.01                            
Temporary equity, shares issued 1,709,650                              
Temporary equity shares price per share | $ / shares $ 18.85                              
Gross cash proceeds from Issuance of convertible preferred stock | $ $ 32,230                              
Series B Convertible Preferred Shares                                
Class Of Stock [Line Items]                                
Temporary equity, shares authorized         0           4,801,493     3,696,943    
Temporary equity, par value | $ / shares         $ 0.01           $ 0.001 $ 0.0001   $ 0.01    
Temporary equity, shares issued         0           4,363,856     2,654,206    
Supplier                                
Class Of Stock [Line Items]                                
Common stock, maximum shares authorized for subscription           700,000 700,000                  
Common stock, shares subscribed but unissued           190,615 190,615                  
Issuance of ordinary shares under subscription agreement | $           $ 1,360                    
Payment receivable upon common stock subscription agreement           $ 1,360 € 1,200