Sangamo Therapeutics and Pfizer have released positive data from the Phase I/II Alta study of investigational SB-525 gene therapy to treat haemophilia A.
Interim data from the trial indicated that SB-525 was generally well-tolerated and demonstrated a dose-dependent increase in Factor VIII levels across the four dosage cohorts.
A total of eight patients were treated across four ascending dosage cohorts for the trial.
The Phase I/II open-label, dose-ranging clinical trial has been designed to assess the safety and tolerability of SB-525 in up to 20 adult patients with severe haemophilia A.
SB-525 is being developed as part of a global collaboration between Sangamo and Pfizer and received Orphan Drug and Fast Track designations from the US Food and Drug Administration.
The European Medicines Agency also granted Orphan Medicinal Product designation to the therapy.
Sangamo Therapeutics chief medical officer Edward Conner said: “The interim data from the first eight patients with haemophilia A treated with SB-525 gene therapy in the Alta study are encouraging and demonstrate a dose-dependent relationship, evidence of sustained factor levels, and low variability, both within each patient and within each cohort.
“These interim results suggest that SB-525 may be well-tolerated and may prove to have the predictability and sustained treatment effect that can bring clinical benefit in patients with haemophilia A.”
The Phase I/II interim data includes eight patients treated across four ascending dosage cohorts of 9e11 vg/kg, 2e12 vg/kg, 1e13 vg/kg and 3e13 vg/kg, with each group consisting of two patients.
Participants were not treated with prophylactic steroids. In the first three cohorts, no treatment-related serious adverse events and ALT elevations were observed.