PRIORITY (PReventing InhibitOR Recurrence IndefiniTelY), A Multi-center, Prospective Study Evaluating the Rate of Inhibitor Recurrence Following Successful ITI in Patients Receiving Ongoing Once Per Weekly Factor VIII Therapy Along with Emicizumab and in Patients Who Discontinue FVIII Therapy and are on Emicizumab for Prophylaxis
Primary objective To demonstrate if inhibitor recurrence is dependent on FViii concentrate exposure after successful iTi. Specific aims 1. To determine the rate of inhibitor recurrence following successful iTi in patients receiving once per week factor Viii concentrate along with emicizumab for prophylaxis (Group-1). 2. To determine the rate of inhibitor recurrences following successful iTi in patients who are not receiving FViii concentrate and are on emicizumab for prophylaxis (Group-2). 3. To assess immunological determinants in patients from both groups.