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
Study to Provide Continued Access to Treatment for Patients Completing a Previous Trial With Efanesoctocog Alfa
This is a multinational, prospective, open-label, roll-over study in patients with haemophilia A, ≥6 years of age, who have completed participation in any of the parental studies with efanesoctocog alfa; XTEND-ed study (LTS16294), FREEDOM study (Sobi.BIVV001-001), PK comparison study (Sobi.BIVV001-003) or SHINE study (Sobi.BIVV001-004). The aim of the study is to provide patients with continuous benefit from efanesoctocog alfa treatment and to further continue clinical monitoring for safety and efficacy until efanesoctocog alfa is commercially available in each patient's respective country (or until March 2027, whichever comes first). The study starts with the Baseline Visit, which will be done in connection to the end of treatment at the EoT/EoS visit (or equivalent) in the respective parent study. Subsequent study visits (on site or phone call) will be done approximately every 13 weeks until End of Treatment. An End of Study safety phone call will be done 14 (+7) days after the End of Treatment Visit.
Phase 3 Clinical Project of Pegylated Recombinant Human Coagulation Factor VIII-Fc Fusion Protein
To evaluate the prophylactic efficacy of recombinant human coagulation factor Ⅷ-Fc fusion protein (FRSW117) for injection in patients with severe hemophilia A. To evaluate the safety of recombinant human coagulation factor Ⅷ-Fc fusion protein (FRSW117) for injection in patients with severe hemophilia A. Secondary purpose: To evaluate the efficacy of recombinant human coagulation factor Ⅷ-Fc fusion protein for injection (FRSW117) in hemostasis and surgical hemostasis in patients with severe hemophilia A. To evaluate the pharmacokinetic (PK) characteristics of recombinant human coagulation factor Ⅷ-Fc fusion protein (FRSW117) for injection in treated patients with severe hemophilia A. To evaluate the immunogenicity of recombinant human coagulation factor Ⅷ-Fc fusion protein (FRSW117) for injection in treated patients with severe hemophilia A.