Sangamo Therapeutics has shared details of their preliminary data from a clinical trial of the investigational drug SB-525 in patients with Haemophilia A. For more detailed information, you can read the source press release at Sangamo’s website by clicking here.
About Haemophilia A
Haemophilia is a condition that reduces the blood’s ability to form clots. In haemophilia A (also called classic haemophilia and Factor VIII deficiency) the blood lacks a certain protein that is involved in the healing of injured blood vessels. Typically, after a blood vessel is injured platelets go to the injury site and set off a chemical reaction involving coagulation proteins, and then a blood clot is formed. All the coagulation proteins need to be present for normal blood clotting to take place. However, people with haemophilia A have reduced levels of coagulation factor VIII. People affected by haemophilia A can experience a range of symptoms and severity, which is often influenced by the level of Factor VIII in the blood.
A potential new gene therapy for haemophilia A is being developed as part of a collaboration between Sangamo Therapeutics and Pfizer. The experimental gene therapy, called SB-525, is a rAAV vector that carries a Factor VIII gene construct. So far, the United States Food and Drug Administration has granted SB-525 Orphan Drug Designation and Fast Track Designation. Additionally, the European Medicines Agency has awarded it Orphan Medicinal Product status.
Research into the Therapy
SB-525 is being investigated in a Phase 1/2 clinical trial called the ‘Alta study’. The study will involve up to twenty adults with severe haemophilia A. It is an open-label and dose-ranging trial that will investigate the safety and tolerability of SB-525. So far, five people have been treated with the therapy at three dose levels, and positive preliminary data has just been shared.
So far, SB-525 seems to have been well tolerated, and no serious adverse events caused by the treatment have occurred. The fifth patient who was treated in June has reportedly achieved therapeutic Factor VIII activity levels. Furthermore, it appears as though SB-525 has a dose-dependent effect. A spokesperson for Sangamo says that they are “encouraged” by these results.