What the trial was testing
The PUPS B-LONG enrolled 33 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
Only 3% of children developed an inhibitor, and most had just over 1 bleed per year on preventive treatment.
Blood advances · 2021 · NCT02234310
These findings — that very few children developed immune resistance to the clotting factor medicine — were published in the Blood advances and represent the headline result of the study.
Researchers tracked outcomes across 33 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
rFIXFc (marketed as Alprolix) is FDA-approved for hemophilia B and was effective in this study of young children starting treatment for the first time. The medicine prevented most bleeds and was given once a week. If your child has hemophilia B, ask your doctor if this treatment might be right for them.
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
A Gene Therapy Study of SPK-8011QQ in Adults With Severe or Moderately Severe Hemophilia A
This study will assess the safety and tolerability of SPK-8011QQ in adult males with moderately severe to severe hemophilia A.
Long-term Anticoagulation in a Patient With Severe Hemophilia A
To date, and to our knowledge, no case of severe hemophilia A patients receiving long-term anticoagulation has been published. Severe hemophilia A is a hereditary bleeding disorder characterized by a factor VIII (FVIII) deficiency of \<1%. Anticoagulation remains a real challenge in these patients, given the precarious hemostatic balance between the bleeding risk associated with anticoagulation and the antithrombotic protection associated with factor VIII deficiency. The advent of new replacement therapies, characterized by FVIII molecules with a prolonged or very prolonged half-life, provides a high level of FVIII coverage (and therefore protection against the risk of bleeding) in patients receiving prophylaxis, thus facilitating the initiation of anticoagulation therapy.