Update of gene therapy in hemophilia A

“Many clinical trial participants have seen FVIII levels at or close to normal. With this experimental treatment, we are researching whether it may be possible for hemophilia A patients to reduce or eliminate FVIII treatment over an extended timeline.”

Safety

The safety data included 2 patients who received VR at 6e12 vg/kg and 2e13 vg/kg, respectively, as well as the 13 patients for whom efficacy data were reported at ASH.

None of the patients developed inhibitors to FVIII, and none withdrew from the study.

The most common adverse events (AEs) across all dose cohorts were alanine aminotransferase elevation (n=11, 73%), arthralgia (n=9, 60%), aspartate aminotransferase elevation (n=8, 53%), headache (n=7, 47%), back pain (n=5, 33%), fatigue (n=5, 33%), and upper respiratory tract infection (n=5, 33%).

Serious AEs were reported in 2 patients. One of these events was considered related to VR.

The patient with the VR-related serious AE was hospitalized for observation after developing grade 2 pyrexia with myalgia and headache within 24 hours of receiving VR. The event resolved within 48 hours of treatment with paracetamol.

The other serious AE was attributed to a planned knee surgery to treat hemophilic arthropathy, and it was grade 1 in severity. No complications were reported. 

*Data in the presentation differ from the abstract.