INdividualized ITI Based on Fviii(ATE) Protection by VWF

The primary goal of the INITIATE trial is to compare the clinical outcome of individualized lot selection to random lot selection utilizing one plasma-derived von Willebrand factor (VWF)/coagulation factor (FVIII) complex concentrate for immune tolerance induction (ITI) in subjects with congenital Hemophilia A, FVIII activity ≤2%, and a historical high-titer inhibitor \[≥5 Bethesda Unit (BU)\].

Participants will be randomized on a one-to-one basis between one of two study arms, individualized lot selection (alternative treatment arm) and random lot selection (standard treatment arm, current US clinical practice in ITI). Study sites, participants, and investigators will be blinded to the treatment status assigned. Alternative treatment arm: Half of the participants will be randomized to blinded individualized lot selection for ITI. The target initial dose of FVIII for ITI is \~200 IU/kg/day intravenously. The suggested maximum dose is 20,000 IU/day. Investigators may adjust the dose to a minimum dose of 150 units/kg if infusion volume is not feasible in patients without central venous access or in patients with von Willebrand factor levels \>250%. Splitting dose into two infusions per day must be approved by the Steering Committee, and if approved, will be considered a protocol deviation. Wilate® will be the VWF/FVIII complex concentrate (Octapharma USA, Inc., U.S. License No. 1646) prescribed for ITI. Individualized lot selection will be performed according to a modified Oxford method in a central laboratory, by testing subject's plasma against 4-6 lots of Wilate® and selecting the one with the highest residual FVIII (lowest Oxford titer) activity remaining after incubation. The same lot will be used throughout the entire ITI course for each subject. If the selected lot is depleted prior to the completion of ITI, a second individualized lot selection will be performed using the original plasma sample provided at baseline. Each Wilate® batch includes 1.6-1.8 million IU and is expected to last for about 3-57 months depending on the weight of the subject and prescribed dose. Standard treatment arm: The other half of the participants will receive random lot selection for ITI. The dose and concentrate used will be the same. Concentrate will be randomly selected from available Wilate® lots. The same lot will be used throughout the entire ITI course for each subject. If the random lot is depleted prior to the completion of ITI, a second lot will be randomly selected. In both cases the random lot will be tested against subject's plasma to measure the residual FVIII activity left after incubation but this result will not affect lot selection. The primary hypothesis is that the time to negative inhibitor (\<0.6 BU) will be shorter with individualized lot selection compared to random lot selection and that this will impact monthly break-through bleeding and reduce costs.