| Share-based compensation | Note 11 — Share-based compensation The following table shows the total share-based compensation expense included in the unaudited consolidated statements of operations (in thousands):  
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
|  |  |  | Three months ended  |  | Six months ended  |  |  
|  |  |  | June 30,  |  | June 30,  |  |  
|  |      | 2021 |      | 2020 |      | 2021 |      | 2020 |  |  |  
| Research and development |  | $ |  2,512 |  | $ |  929 |  | $ |  4,887 |  | $ |  1,907 |  |  |  
| General and administrative |  |   |  2,937 |  |   |  1,695 |  |   |  5,896 |  |  |  2,165 |  |  |  
|  |  | $ |  5,449 |  | $ |  2,624 |  | $ |  10,783 |  | $ |  4,072 |  |  |   The following table shows information about share options and options which have a nominal exercise price (similar to restricted stock units (RSUs)) granted: 
|  |  |  |  |  |  |  |  |  |  |  |  |  |  |  
|  |  |  | Three months ended  |  | Six months ended  |  
|  |  |  | June 30,  |  | June 30,  |  
|  |  | 2021 |      | 2020 |      | 2021 |      | 2020 |  |  
| Number of options over ordinary shares granted |  |  | 918,048 |  |  | 2,738,936 |  |  | 15,721,104 |  |  | 12,968,216 |  |  
| Weighted average fair value of ordinary shares options |  | $ | 0.65 |  | $ | 0.30 |  | $ | 0.75 |  | $ | 0.47 |  |  
| Number of additional options with a nominal exercise price granted |  |  | 1,995,456 |  |  | 778,120 |  |  | 14,659,248 |  |  | 6,838,816 |  |  
| Weighted average fair value of options with a nominal exercise price  |  | $ | 0.88 |  | $ | 0.43 |  | $ | 1.01 |  | $ | 0.71 |  |   |