v3.26.1
Related party (Details) - USD ($)
$ in Thousands
3 Months Ended 6 Months Ended
Jun. 30, 2026
Jun. 30, 2025
Jun. 30, 2026
Jun. 30, 2025
Dec. 31, 2025
Related party          
Research and development $ 3,478 $ 2,320 $ 5,579 $ 4,647  
Related party payable $ 1,897   $ 1,897   $ 3,312
Other Liability, Current, Related Party [Extensible Enumeration] Related Party [Member]   Related Party [Member]   Related Party [Member]
Shared Services Agreement          
Related party          
Research and development $ 200 $ 1,300 $ 900 $ 2,400  
Related party payable $ 1,900   $ 1,900   $ 3,300
Other Liability, Current, Related Party [Extensible Enumeration] Related Party [Member]   Related Party [Member]   Related Party [Member]
Other Liability, Current, Related Party, Name [Extensible Enumeration] mtva:DongStMember   mtva:DongStMember   mtva:DongStMember
Extended terms payable $ 1,400   $ 1,400    
Extended terms amount to be paid on June 30, 2026 700   700    
Extended terms amount to be paid on September 30, 2026 700   700    
Extended terms, Accrued interest payable 100   $ 100    
Fixed interest rate     4.60%    
Amount payable in clinical trial accrued liabilities $ 400   $ 400