Pfizer’s Phase 3 AFFINE study evaluating giroctocogene fitelparvovec for the treatment of adults with moderately severe to severe haemophilia A has met its primary endpoint (PE).
Giroctocogene fitelparvovec is being developed by Pfizer under a collaboration with Sangamo Therapeutics as a gene therapy for the blood clotting disorder.
In late 2019, Pfizer took over the clinical studies, regulatory activities, and potential global commercialisation of the investigational gene therapy.
The Phase 3 AFFINE study is an open-label, multicentre, single-arm trial designed to assess the efficacy and safety of a single infusion of giroctocogene fitelparvovec.
It enroled 75 adult male participants among which 50 were included in the primary efficacy analysis. These patients completed at least six months of routine FVIII replacement prophylaxis therapy during the lead-in study.
AFFINE met its primary objective, demonstrating both non-inferiority and superiority of total annualised bleeding rate (ABR) from Week 12 through at least 15 months post-infusion compared to routine FVIII replacement prophylaxis therapy.
After a single infusion of giroctocogene fitelparvovec, there was a statistically significant decrease in mean total ABR compared to the pre-infusion period.
The key secondary endpoints were also achieved, demonstrating superiority compared to prophylaxis.
Furthermore, the investigational therapy was generally well tolerated.
Pfizer research and development internal medicine and infectious diseases chief development officer and senior vice president James Rusnak said: “We are very pleased with these positive results from the Phase 3 AFFINE study demonstrating the safety and efficacy of our one-time gene therapy candidate for people with haemophilia A.
“We look forward to advancing this latest innovation to help address the medical and treatment burden associated with frequent and time-consuming IV infusions or injections, building on Pfizer’s more than 40-year effort to advance hemophilia treatment.”
The AFFINE study participants will undergo evaluation over five years, with up to 15 years included in a long-term follow-up study.
Pfizer intends to discuss the results from the AFFINE trial with regulatory authorities in the coming months.
Giroctocogene fitelparvovec has received fast track and regenerative medicine advanced therapy designations from the US Food and Drug Administration (FDA), along with orphan drug designations in the US and the European Union.
Recently, Pfizer obtained FDA approval for Beqvez (fidanocogene elaparvovec), its gene therapy for haemophilia B.
