Sangamo’s gene therapy offers hope to hemophilia patientsPublished: December 10, 2019
Sangamo Therapeutics has announced encouraging interim results from its ongoing Phase 1/2 study evaluating an AAV-based gene therapy approach to treat severe he-mophilia A.
Data presented at the American Society of Hematology (ASH) meeting in Orlando, FL has reported encouraging results from Sangamo’s and Pfizer’s Phase 1/2 Alta gene therapy trial.
The Alta study of SB-525 is designed to evaluate the safety and kinetics of a single intravenous infusion of SB-525 in hemophilia A patients. SB-525 is a recombinant AAV vector 6 encoding the complementary deoxyribonucleic acid for B domain deleted human FVIII.
The study evaluated 11 pa¬tients across four ascending dosage cohorts; two patients in the first three cohorts and 5 patients in the highest dose (3e13 vg/kg) cohort. Patients demonstrated a dose-dependent increase in FVIII levels and dose-dependent decrease in the use of FVIII replacement therapy. Patients in the highest dose cohort achieved normal FVIII levels starting at 5-7 weeks following the therapy. The treatment was generally well tolerated.
2 patients in the 3e13 vg/kg cohort continue to have normal FVIII levels through 44 and 37 weeks of follow-up. The next two patients in this cohort are at 7 and 4 weeks of follow-up and have demonstrated FVIII activity kinetics similar to that of the previous patients in the same cohort. The two patients most recently treated in this cohort are at 22 and 12 weeks of follow-up, respectively, and have demonstrated a similar pattern of FVIII expression. One patient who is currently at week 24 of follow-up had achieved normal FVIII expression at 7 weeks following treatment, but the levels fluctuated at week 13. However, at week 18, FVIII levels began to increase, and as of the latest measurement at week 24, it is stable. No patient in this cohort experienced bleeding events up to 44 weeks of follow-up.
Sangamo and Pfizer entered into a global collaboration and license agreement in 2017 for the SB-525 program. Later the collaboration was also extended to developing gene therapies for amyotrophic lateral sclerosis and frontotemporal lobar degeneration using Sangamo’s proprietary zinc finger protein transcription factor technology.
SB-525 received FDA’s Orphan Drug and Fast Track designations and EMA’s Orphan Medicinal Product designation. FDA had also granted regenerative medicine advanced therapy (RMAT) designation for SB-525 gene therapy to treat severe hemophilia A, a designation which allows the company to interact with FDA more frequently.
Sangamo has completed the manufacturing technology transfer and initiated the transfer of the Investigational New Drug (IND) Application to Pfizer, which is expected to be completed in the first quarter 2020.
Dr Bettina Cockroft, Sangamo’s CMO commented: “The updated results from the Alta study suggest that SB-525 may represent a differentiated gene therapy for patients with severe hemophilia A. The results continue to suggest that if sustained over a longer duration, SB-525 has the potential to be a predictable, reliable, and safe treatment that may bring clinical benefits to patients with severe hemophilia A.”
Source: Sangamo and Pfizer Announce Updated Phase 1/2 Results Showing Sustained Increased Factor VIII Activity Through 44 Weeks Following SB-525 Gene Therapy Treatment; News