Eloctate use in immune tolerance induction (ITI) therapy shows promise in high-risk patients with severe hemophilia A and inhibitors treated for the first time, Bioverativ announced. The results support a potential benefit for some patients who tried and failed ITI with other factors.
The study, “Recombinant factor VIII Fc fusion protein for immune tolerance induction in patients with severe haemophilia A with inhibitors—A retrospective analysis,” was published in the journal Haemophilia.
A third of hemophilia A patients who are treated with factor VIII replacement therapy tend to develop inhibitors against the therapy, increasing their risk for bleeds and long-term joint damage.
Immune tolerance induction is considered the best choice to eradicate factor VIII inhibitors in these patients. However, ITI usually requires patients undergo therapy for an extended period so the immune system learns not to attack the factor VIII being administered.
Eloctate is the first extended half-life FVIII approved to treat hemophilia A, but data showing how it performs when used in ITI therapy is still limited.
In a recent retrospective analysis, researchers evaluated data from 19 patients with severe hemophilia A who received immune tolerance induction therapy using Eloctate – seven were being treated with ITI for the first time, and the remaining 12 were a pretreated group.
The results showed that tolerization was achieved after a median of 7.8. months in four of the seven first-time immune tolerance induction patients. The remaining three patients continue on Eloctate-ITI therapy, but two patients already show a reduction in the levels of inhibitor.
Among the 12 patients who failed to respond to previous therapies, seven patients achieved a negative inhibitor level in a median 3.3 months, but in four patients inhibitors came back. Four rescue patients did not show a response to ITI with Eloctate, and one responded to the therapy and showed a reduction in inhibitor levels.
“Most rescue patients in this study were still undergoing rFVIIIFc ITI at the time of data collection, and therefore, a longer follow-up is needed to determine their final outcomes,” researchers wrote.
At the time of analysis, the majority of participants (16 of 19) was undergoing treatment with Eloctate, either as a prophylaxis (preventive treatment) or immune tolerance induction therapy, without any reports of adverse events.
“The results of this analysis are encouraging and support the need for additional and ongoing scientific research on Eloctate in ITI to determine whether an Fc-based recombinant factor VIII therapy can rapidly tolerize patients with inhibitors,” Maha Radhakrishnan, MD, senior vice president of medical at Bioverativ, said in a press release.
Swedish Orphan Biovitrum (SOBI) and Bioverativ launched two Phase 4 clinical trials (NCT03093480 and NCT03103542), currently recruiting participants, to further investigate the performance of Eloctate in ITI in patients with severe hemophilia A and inhibitors.