Pfizer reports positive topline results from phase 3 AFFINE study of haemophilia A gene therapy candidate

Pfizer Inc. reported positive results from the Phase 3 AFFINE study (NCT04370054) of giroctocogene fitelparvovec, a gene therapy for adults with moderately severe to severe hemophilia A. The study met its primary objective, showing that giroctocogene fitelparvovec significantly reduced the annualized bleeding rate (ABR) compared to standard Factor VIII (FVIII) replacement therapy. A single dose led to a notable decrease in ABR from 4.73 pre-infusion to 1.24 post-infusion.

The study also achieved key secondary endpoints, with 84% of participants maintaining FVIII activity >5% at 15 months. Giroctocogene fitelparvovec was generally well tolerated, though 49.3% of participants had transient elevated FVIII levels.

This gene therapy aims to provide long-term FVIII production with a single infusion. Further data will be presented at upcoming medical meetings. Pfizer is also advancing other hemophilia treatments, including Beqvez (fidanocogene elaparvovec) and marstacimab.