A Research Study Looking at Mim8 in Children With Haemophilia A With or Without Inhibitors

Inclusion criteria

• Informed consent obtained before any study-related activities. Study-related activities are any procedures that are carried out as part of the study, including activities to determine suitability for the study.
• Male and female participants with the diagnosis of congenital haemophilia A of any severity based on medical records.
• Aged 1-11 years (both inclusive) at the time of signing informed consent.
• For previously treated participants :

• Participant has been prescribed treatment with FVIII concentrate or bypassing agent in the last 26 weeks prior to screening.
• Participants with endogenous FVIII activity greater than or equal to 1%, based on medical records, must have at least 1 treated bleed during the previous 26 weeks before screening for which factor VIII concentrate or bypassing agent has been prescribed (no requirements for participants with FVIII activity below 1%).
• For previously untreated participants:

a. Diagnosis of severe haemophilia A (endogenous FVIII activity below 1%) based on medical records.

• Child and parent/caregiver willingness and ability to comply with scheduled visits and study procedures, including the completion of diary and patient-reported outcomes questionnaires.( For China mainland; assessed at the investigator's discretion unless otherwise stated.)

Exclusion criteria

• Known or suspected hypersensitivity to trial product or related products.(For China mainland; assessed at the investigator's discretion unless otherwise stated.)
• Previous participation in this study. Participation is defined as signed informed consent.
• Participation (i.e., signed informed consent) in any interventional clinical study with receipt of last dose within 6 months (or 5 half-lives of the investigational medicinal product, whichever is shorter) before planned randomisation.
• Exposure to non-factor haemostatic products for bleeding prophylaxis within 6 months (or 5 half-lives of the medicinal product, whichever is shorter) before planned randomisation, for participants not included in the run-in.
• Known congenital or acquired coagulation disorders other than haemophilia A.
• Other conditions (e.g. autoimmune disease) or laboratory abnormality that may increase risk of bleeding or thrombosis, as evaluated by the investigator.(For China mainland; assessed at the investigator's discretion unless otherwise stated.)
• Any disorder, except for conditions associated with haemophilia A, that in the investigator's opinion might jeopardise the participant's safety or compliance with the protocol.(For China mainland; assessed at the investigator's discretion unless otherwise stated.)
• Mental incapacity, unwillingness to cooperate or a language barrier precluding adequate understanding and cooperation.(For China mainland; assessed at the investigator's discretion unless otherwise stated.)
• Lack of adequate parental/caregiver support to enter accurately and timely information regarding treatment and bleeding episodes into an (electronic) diary.(For China mainland; assessed at the investigator's discretion unless otherwise stated.)
• Previous or current treatment for thromboembolic disease (with the exception of previous catheter-associated thrombosis for which anti-thrombotic treatment is not currently ongoing) or signs of thromboembolic disease.
• Major surgery planned to take place after screening.(For China mainland; assessed at the investigator's discretion unless otherwise stated.)
• Immune tolerance induction planned to take place after treatment initiation.(For China mainland; assessed at the investigator's discretion unless otherwise stated.)
• Hepatic dysfunction defined as aspartate aminotransferase (AST) and/or alanine aminotransferase (ALT) greater than 3 times the upper limit of normal combined with total bilirubin greater than 1.5 times the upper limit of normal measured at screening.
• Serum creatinine above 1.5 x upper limit of normal (ULN), measured at screening.
• Pregnancy (female participants).(Will be assessed at investigator's discretion, according to suspicion of pregnancy.)