A Research Study Investigating Denecimig (Mim8) in Adults With Acquired Haemophilia A

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 or female participants (sex assigned at birth, inclusive of all gender identities) newly diagnosed with acquired haemophilia A (AHA) prior to signing the informed consent form, with AHA diagnosis (FVIII activity lesser than (\<) 50 percentage (%) and FVIII inhibitors greater than (\>) 0.6 Bethesda units \[BU\]) confirmed at screening. * Treatment-requiring bleed(s) due to AHA from diagnosis and until screening. * The participant is capable of following study procedures and able to seek medical attention when needed. Exclusion Criteria: * Female who is pregnant, breast-feeding or intends to become pregnant or is of childbearing potential and not using an adequate and highly effective contraceptive method. * Previous or current thromboembolic disease or eventsa (with the exception of previous catheter associated thrombosis for which anti-thrombotic treatment is not currently ongoing) or risk of thromboembolic disease. * Life expectancy \<3 months at the time of screening, as evaluated by the investigator. * Therapy with immunosuppressive or immune modulating drugs for treatment of AHA (other than less than or equal to (≤) 2 days of prednisolone (or equivalent) for AHA at a dose ≤100 mg per day) prior to screening. * Immunosuppressive therapy (IST) initiated prior to AHA diagnosis for other medical conditions (e.g., other autoimmune disorders) is permitted, provided it was initiated greater than or equal to (≥) 6 months prior to screening, has been maintained at a stable dose and regimen since initiation, and is expected to remain at a stable dose and regimen at least during the main treatment period (Weeks 0-12).