A Study to Learn About How Changing Therapy From Emicizumab to Marstacimab Affects People With the Severe Hemophilia A.

Orthopaedic Institute for Children/Orthopaedic Hemophilia Treatment Center, Los Angeles, California, United States

Brody School of Medicine at East Carolina University, Greenville, North Carolina, United States

ECU Health Medical Center, Greenville, North Carolina, United States

Nirmal Hospital Pvt Ltd., Surat, Gujarat, India

K J Somaiya Hospital & Research Centre, Mumbai, Maharashtra, India

Ege University Faculty of Medicine Dean's Office, Bornova, İzmir, Turkey (Türkiye)

Istanbul Universitesi Tıp Fakultesi Onkoloji Enstitusu, Fatih, İ̇stanbul, Turkey (Türkiye)