What the trial was testing
The XTEND-1 enrolled 159 patients with hemophilia. The study was sponsored by Bioverativ, a Sanofi company and tracked outcomes across the full group of patients who matched the trial's eligibility profile.
It was a large trial designed to confirm whether the treatment works well enough for wider use. Trials at this stage are designed to produce evidence regulators and physicians can act on — not just observations to follow up later.
What the results showed
Bleeding episodes dropped 77% with once-weekly efanesoctocog alfa compared to previous prevention treatment.
The New England journal of medicine · 2023 · NCT04161495
These findings — that patients had three-quarters fewer bleeds per year compared to their previous treatment — were published in the The New England journal of medicine and represent the headline result of the study.
Researchers tracked outcomes across 159 patients enrolled in the trial. The result was consistent enough across the group that the team felt confident reporting it.
What this means for patients
For patients with hemophilia, this result changes the calculus on what to ask their care team about. Whether it changes day-to-day care depends on factors like disease subtype, prior treatments, and where the patient is in their care journey.
What you can do now
Efanesoctocog alfa is FDA-approved and sold as Altuviiio. It's given once a week instead of the more frequent injections many hemophilia A treatments require. Ask your doctor if this extended-protection option might work for you.
Eligibility for the treatments mentioned above depends on specific test results and clinical history. Bring this summary, the trial name, and your most recent labs or pathology report to your next visit.
Open hemophilia trials
ITI Using SCT800 Alone or Combining Daratumumab in Hemophilia A Adolescents and Adults With High Titer Inhibitor
To evaluate the time of response, sustained remission rate, and relapse rate of CD38 monoclonal antibody (Daratumumab) combined with SCT800 (rFVIII) in the treatment of hemophilia A adolescents and adults with high titer inhibitors.
Study of Recombinant Human Coagulation Factor VIII-Fc Fusion Protein (FRSW107) On-Demand Treatment
The indication for this product is to control bleeding in patients with hemophilia A (congenital deficiency of factor VIII). The primary objective: Evaluation of the efficacy of recombinant human coagulation factor VIII-Fc fusion protein for injection (FRSW107) as an on-demand treatment in previously treated patients with severe hemophilia A. Secondary objectives: Evaluation of the safety and immunogenicity of FRSW107 as an on-demand therapy in previously treated patients with severe hemophilia A. Evaluate the on-demand treatment's PK profile of FRSW107 in previously treated patients with severe hemophilia A based on population pharmacokinetic (PopPK) methods ; preliminarily investigate the exposure-response (E-R) relationship of FRSW107 on-demand treatment in these patients if data permit.