CSL Behring’s Therapy for Severe Hemophilia A Shows Promise in Clinical Study

CSL Behring’s rVIII-SingleChain, a novel recombinant Factor VIII (rFVIII) treatment candidate, recently demonstrated effectiveness in surgery and in the control of bleeding in patients with severe hemophilia A.

The Phase 1 to Phase 3 clinical trial results, recently published in the journal Blood, also demonstrated low annualized bleeding rates in patients on a medication, and it was well tolerated. The research paper detailing the therapeutic effects is titled “Efficacy and safety of rVIII-SingleChain: results of a phase I/III multicenter clinical trial in severe hemophilia A.”

The clinical study of rVIII-SingleChain, “An Open-label Safety, Efficacy and Pharmacokinetic Study of a Recombinant FVIII Compared to Recombinant Human Antihemophilic FVIII in Patients With Severe Hemophilia A,” was conducted by Dr. Ingrid Pabinger, MD, professor at the Medical University of Vienna, and her colleagues.

The study’s main objective was to assess the therapy’s effectiveness for the treatment of hemophilic bleeding episodes and as a routine and surgical medication.

The study included 173 adolescent and adult patients treated with rVIII-SingleChain. Of the total, 146 were assigned the medication as prophylaxis (preventive measure) and 27 received it as on-demand therapy. Researchers observed a total of 848 bleeding events which were treated with rVIII-SingleChain, either as on-demand therapy (590) or prophylaxis (258).

Treatment with the novel therapy controlled 72.2% of the bleeding events with excellent efficacy, and 21.6% of bleeding events showed good efficacy. In the remaining 52 events (6.2%), the therapy demonstrated moderate effectiveness.

Importantly, 43% of patients treated with the product as a preventive measure (prophylaxis) had no bleeding events. Surgical hemostasis was rated excellent to good in all of the 16 surgeries on study, and none of the participants was found to develop FVIII inhibitors.

The most common reported adverse events were headache, arthralgia (joint pain), and nasopharyngitis.

“This study, which was designed to reflect clinical practice, demonstrated with a robust dataset that rVIII-SingleChain is highly efficacious in the treatment of bleeding events, routine prophylaxis, and in controlling hemostasis in a variety of surgical procedures in adolescents and adults with severe hemophilia A,” the authors wrote in a news release.

“The study also demonstrated that rVIII-SingleChain has a favorable safety profile and is well tolerated. Very low annualized bleeding rates in patients on individualized prophylaxis hopefully has the potential to translate into prolonged freedom from debilitating joint disease,” they wrote.