The purpose of this non-interventional, observational, real-world study is to find out what are the real-world experiences of people living with hemophilia A or B\[OK1.1\] who start the study medicine (called marstacimab) in routine clinical practice. Hemophilia is a rare genetic condition where the blood does not clot normally, meaning people bleed longer than usual after an injury.
This study is seeking participants who are living with hemophilia A or B and:
- Have a medical record documenting hemophilia A or hemophilia B. A hematologist must have confirmed the diagnosis before they join the study.
- Are under current treatment with marstacimab or have a prescription to start the treatment with marstacimab
- Are 6 years of age or older and the recipient of medical care in the United States All participants in this study will receive their usual treatment for hemophilia A or hemophilia B Participants will take part in this study for 1 year. During this time, they will complete up to six surveys. These surveys will be given between enrollment and about one year after marstacimab is started.
Some participants in the study may be asked to take part in interviews. During these interviews they will be asked about their experience with hemophilia or marstacimab.
The study will provide information about how well the marstacimab treatment works. It will also assess treatment burden, and treatment preferences. This information will help to determine its benefit compared to existing treatment options. It will also help doctors make treatment decisions and optimize hemophilia care.
