Pfizer and Sangamo Therapeutics have re-opened the recruitment for the phase 3 AFFINE study of giroctocogene fitelparvovec, an investigational gene therapy for patients having moderately severe to severe haemophilia A.

According to Pfizer, the trial sites will re-start patient enrolment this month and the dosing is expected to resume next month.

The pharma major mentioned that all the trial sites are expected to be active by the end of this year and the findings could be released in the first half of 2024.

AFFINE is an open-label, multicentre, single-arm study which will assess the effectiveness and safety of a single infusion of giroctocogene fitelparvovec. The late-stage trial is expected to enroll over 60 adult male participants of age 18-64 with moderate to severe haemophilia A.

Pfizer said that the eligible participants must have finished at least six months of routine FVIII prophylaxis therapy during the lead-in phase 3 study for collecting pretreatment data for efficacy and certain safety parameters.

The primary endpoint of the AFFINE gene therapy trial is the impact on annualised bleeding rate (ABR), 15 months after receiving treatment with the investigational candidate. This will be compared with ABR on previous FVIII prophylaxis replacement treatment.

Among the secondary endpoints of the phase 3 trial is the activity level of FVIII after the onset of steady state and through 15 months after being infused with giroctocogene fitelparvovec.

The gene therapy candidate is being developed under a collaboration deal for the global development and commercialisation of gene therapies for hemophilia A between Sangamo Therapeutics and Pfizer. In 2019, the former transferred giroctocogene fitelparvovec’s manufacturing technology and the investigational new drug (IND) application to Pfizer.