This is a single arm, phase 4, prospective, open-label, United States single-center study to assess the hemostatic efficacy and safety of Hemlibra (emicizumab) for hemostatic control of hemophilia A patients, (baseline FVIII level <40%), children and adults, with and without inhibitors with hemophilic pseudotumors; secondary outcomes will assess changes in quality of life and activity level in treated patients.~Hemlibra (emicizumab) will be administered as primary weekly prophylaxis after the enrollment/screening visit is complete (approximately 7-10 days after screening, if laboratory results are available and eligibility is confirmed). If an activity monitoring device is typically utilized by the patient (eg, a Fitbit) then permission will be requested from the patient at screening to access the data for 1 month prior to screening as a baseline comparator for post-treatment activity. The use of an activity-monitoring device is not required by the study.~The enrollment period is 2 years and the study will last a maximum of 4 years; subjects will receive study medication (Hemlibra, emicizumab) for a minimum of 2 years and a maximum of 4 years based upon time of enrollment. Hemlibra (emicizumab) will be administered using the FDA-approved once-weekly dosing regimen for loading dose and prophylactic dose. Breakthrough bleeding events will be recorded and treated with locally available FVIII (eg, pdFVIII or rFVIII) in non-inhibitor subjects and inhibitor subjects with low titer inhibitors (titer<5 BU). The lowest dose of FVIII expected to achieve hemostasis will be utilized for treatment of breakthrough bleeding events in non-inhibitor and low-titer inhibitor patients. Subjects with high-titer inhibitors (titer ≥5 BU) and those with low titer inhibitors who do not respond to FVIII will be required to utilize rFVIIa as first line therapy; aPCC (<100 U/kg/day for preferably no more than 1 day) may only be used upon approval of the Study Investigator and under the supervision of a physician.~The proposed study is seeking to address the following knowledge gaps:~Does weekly prophylactic Hemlibra (emicizumab) reduce the rate of bleeding events in subjects with hemophilia A and pseudotumor, including the rate of hospitalization, anemia and transfusion? Does weekly prophylactic Hemlibra (emicizumab) control the progression of hemophilic pseudotumor? Does weekly prophylactic Hemlibra (emicizumab) result in an increase in QoL and activity level?
This is a single arm, phase 4, prospective, open-label, United States single-center study to assess the hemostatic efficacy and safety of Hemlibra (emicizumab) for hemostatic control of hemophilia A patients (baseline FVIII level <40%) with and without inhibitors with hemophilic pseudotumors; secondary outcomes will assess changes in quality of life and activity level in treated patients.