Efanesoctocog Alfa Prophylaxis in Patients With Hemophilia A With Synovial Hypertrophy

Prior treatment

• Has a current diagnosis of an factor VIII (FVIII) inhibitor, defined as inhibitor titer ≥0.60 BU/mL.
• Has ITI within the last 2 years prior to the baseline visit (Visit 2).
• Has been enrolled in a concurrent clinical interventional study or exposed to other investigational drug(s) within 3 months prior to screening for this study.

Other illness

• Has other associated clotting disorders at the time of consent/assent.
• Is not suitable for participation, whatever the reason, as judged by the investigator, including medical or clinical conditions, or patients potentially at risk of noncompliance to study procedures.
• Has hypersensitivity to efanesoctocog alfa or its components or any of its excipients that, in the opinion of the investigator, contraindicates participation in the study.
  • The above information is not intended to contain all considerations relevant to a patient's potential participation in a clinical trial.

Other

• Participants are excluded from the study if any of the following criteria apply:
• Is already under efanesoctocog alfa treatment.
• Is currently in an institution because of regulatory or legal order (that is, is a prisoner or a patient who is legally institutionalized).
• Is an employee or family member of the investigator or site personnel.
• Is involved in a specific situation during study implementation or the course of the study that may raise ethics considerations.

• Participant is diagnosed with moderate to severe hemophilia A (defined as less than or equal to (≤)5 percent (%) of endogenous FVIII clotting activity) at the time of consent/assent.
• Participant is more than or equal to (≥)12 years old at the time of consent/assent.
• Participant has existing synovial hypertrophy, defined as at least 1 eligible\* joint by the HEAD-US score (Synovitis score: 1 or 2) at the time of consent/assent.
• Participant has at least 1 eligible\* joint without planned future major orthopedic procedures (example, arthroscopic synovectomy, radioisotopic or chemical synoviorthesis), or major orthopedic procedures in the past 3 months prior to the screening visit (Visit 1).
  • \*An eligible joint is a joint with existing synovial hypertrophy, as defined by a HEAD-US synovitis score of 1 or 2, considering hypertrophic synovium as an indication of the presence of synovitis
• Participant has received prophylactic treatment with hemophilia prophylaxis prescriptions in the last 12 months prior to the baseline visit (Visit 2).
• Participant is capable of understanding the written Informed Consent Form (ICF)/assent form, provides a signed and witnessed written ICF/assent form, and agrees to comply with the protocol requirements.
• If male, no contraceptive measures are required for this study.
• If female, is not pregnant or breastfeeding, and one of the following conditions applies:
• Is a women of nonchildbearing potential (WONCBP)
• Is a WOCBP and agrees to use a highly effective contraceptive method, with a failure rate of less than (\<)1 percent during the study treatment period (at least until the Week 52/ End of Treatment \[EoT\] visit).
• A WOCBP must have a negative serum pregnancy test at the screening visit (Visit 1)