Phase III Multi-Center, Randomized, Controlled Inhibitor Eradication Trial, Comparing Eloctate Immune Tolerance Induction (ITI) Plus Emicizumab vs. Eloctate ITI Alone to Eradicate Inhibitor Formation in Severe Hemophilia A

This is a multi-center randomized phase III clinical trial, the Inhibitor Eradication Trial, in which Eloctate ITI plus Emicizumab will be compared with Eloctate ITI alone to eradicate inhibitors in patients with severe hemophilia A This adaptive design is necessary as randomized trials in rare diseases are often not possible. The INHIBIT Clinical Trials Platform includes two linked trials, the Inhibitor Prevention Trial (Prevention Trial) and the Inhibitor Eradication Trial (Eradication Trial) that will be conducted at up to 41 U.S. hemophilia treatment centers (HTCs) affiliated with universities. The Inhibitor Eradication Trial is a 48-week randomized phase III trial, in which 90 previously treated patients (PTPs) with severe hemophilia A and high-responding inhibitors (anti-VIII > 0.6 B.U.), will be enrolled. Subjects will include individuals with severe hemophilia A who develop inhibitors during the linked Inhibitor Prevention Trial and adults or children at the same HTCs refractory to or never undergoing immune tolerance induction (ITI). Once enrolled, subjects who meet all the inclusion and none of the exclusion criteria, will be randomized to weekly Eloctate ITI plus weekly Emicizumab vs. weekly Eloctate ITI alone to eradicate inhibitor formation, defined as anti-FVIII<0.6 B.U. Blood draws will be minimized to 6 timepoints, pre, 4, 12, 24, 36, and 48 weeks, and validated for small volumes, 3.8 cc (¾ tsp) each. The Inhibitor Eradication Trial is considered greater than minimal risk as study drug is given before the first bleed and special inhibitor studies are obtained. (NB: The Inhibitor Eradication Trial (PRO19070080) is linked to the Inhibitor Prevention Trial (PRO19040140), as part of the INHIBIT Clinical Trials Platform, and both trials will be conducted efficiently in the same hemophilia treatment centers (HTCs), with the same MDs, coordinators, visit frequency, blood sampling, and assays.