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Hemophilia ANovember 2019Summary reviewed May 2026

A Daily Injection Cut Bleeding Rates to 3-7 Bleeds Per Year in Hemophilia Patients

This 53-patient trial tested concizumab — a daily under-the-skin injection that boosts the clotting cascade — for hemophilia A and B with or without inhibitors. Bleeding rates dropped substantially across all groups.

What the trial was testing

The trial enrolled 26 patients with hemophilia a. The study was sponsored by Novo Nordisk and tracked outcomes across the full group of patients who matched the trial's eligibility profile.

It was initial testing (phase 2). 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

Annual bleeding rates dropped to 3-7 per year on concizumab.

Blood · 2019 · NCT03196284

These findings — that on daily concizumab in hemophilia A or B with inhibitors — were published in the Blood and represent the headline result of the study.

Researchers tracked outcomes across 26 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 a, 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

Concizumab (Alhemo) is FDA-approved and available now for hemophilia A and B with inhibitors in patients 12 and older. It is given as a daily under-the-skin injection. Ask a hemophilia treatment center about access if existing prophylaxis is not working.

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.