Phase 3 AFFINE study is an open-label, multicentre, single-arm study, designed to evaluate the efficacy and safety of giroctocogene fitelparvovec


Pfizer, Sangamo dosed first patient in Phase 3 AFFINE trial. (Credit: Coolcaesar/Wikipedia.)

Pfizer and its partner Sangamo Therapeutics have dosed the first participant in the Phase 3 AFFINE study, evaluating giroctocogene fitelparvovec, a potential gene therapy for haemophilia A.

The Phase 3 AFFINE study is an open-label, multicentre, single-arm study, designed to evaluate the efficacy and safety of giroctocogene fitelparvovec in more than 60 adult male participants, aged between 18 and 64 years, suffering from moderately severe to severe haemophilia A.

The study participants would be analysed throughout the study period, for five years, after the single infusion of the drug to further evaluate the durability and efficacy.

Impact on the annual bleed rate (ABR) for 12 months, after treatment with giroctocogene fitelparvovec, compared to that of Factor VIII (FVIII) replacement therapy is the primary endpoint of the study.

FVIII activity level following the onset of steady-state after infusion of giroctocogene fitelparvovec, for 12 months is the secondary endpoint.

The US drugmaker said that the initiation of Phase 3 study follows an earlier Phase 1/2 study, which demonstrated that the drug was generally well-tolerated in all cohorts of the trial.

Pfizer rare disease global product development chief development officer Brenda Cooperstone said: “The initiation of the pivotal Phase 3 dosing study of giroctocogene fitelparvovec is a significant achievement for Pfizer as we continue our longstanding commitment to improving care for the haemophilia community.

“Enrollment in the lead-in study is progressing well and recruitment is on track for Phase 3. Given the Phase 1/2 study findings to date, we believe that giroctocogene fitelparvovec has the potential to sustain factor levels and reduce annual bleed rates, suggesting this one-time gene therapy could potentially transform the standard of care for eligible patients worldwide.”

Pfizer, Sangamo partnered to develop giroctocogene fitelparvovec for haemophilia A

In May 2017, Pfizer and Sangamo have entered into a collaboration to develop giroctocogene fitelparvovec. It contains a recombinant adeno-associated virus serotype 6 vector (AAV6) encoding the complementary DNA for B domain deleted human FVIII.

Under the terms of the collaboration deal, Sangamo would receive a total of up to $300m for the development and marketing of giroctocogene fitelparvovec, and up to $175m for an additional gene therapy agent to be developed for haemophilia A treatment.

The company is also entitled to receive additional tiered royalties of up to 20% on the annual net sales of giroctocogene fitelparvovec.

Pfizer is responsible for the research, development, manufacturing and marketing of the drug. The company has paid $30m to Sangamo in milestone payment.

Giroctocogene fitelparvovec has received the US Food and Drug Administration (FDA) Orphan Drug, Fast Track, and regenerative medicine advanced therapy (RMAT) designations, along with Orphan Medicinal Product Designation from the European Medicines Agency (EMA).

Sangamo chief medical officer Bettina M Cockroft said: “We are encouraged that findings from the Phase 1/2 Alta study met two critically important measures for the haemophilia A patient community, showing clinically meaningful factor levels and reduced bleeds.

“The progress of this program, the most advanced of our gene therapy product candidates, into Phase 3 is an important milestone for Sangamo, as it represents our first asset in a registrational trial.”