Long-term safety, efficacy of hemophilia B therapy

For children ages 6 to 11, the median ABR was 2.7 in the weekly prophylaxis group (n=10) and 2.4 in the individualized prophylaxis group (n=5). The patient in the modified prophylaxis group had an ABR of 3.1.

Safety

The researchers said rFIXFc was well-tolerated, and the adverse events (AEs) reported were typical of the population studied.

AEs were reported in 75.9% of patients. The most common were headache (n=14, 12.1%) and common cold (n=13, 11.2%), and the majority of AEs were considered unrelated to rFIXFc.

Three adult/adolescent patients experienced AEs during B-YOND that were considered treatment-related, including noncardiac chest pain, hematuria, and obstructive uropathy. All 3 events resolved.

One patient experienced breath odor during B-LONG that was considered treatment-related. And 1 patient reported decreased appetite during Kids B-LONG that was considered treatment-related. Neither of these events resolved.

There were 39 serious AEs in 23 patients (19.8%). All but 1 of these events were considered unrelated to rFIXFc.

The treatment-related serious AE was renal colic in a patient originally enrolled in the B-LONG study. The patient had a medical history of previous clot colic. The event resolved and did not lead to study discontinuation.

There have been no reports of serious allergic reactions or anaphylaxis associated with rFIXFc, no vascular thrombotic events, and no deaths.