SB-525 was cleared by the U.S. Food and Drug Administration (FDA) in January as an investigational new drug (IND) for the treatment of hemophilia A. Earlier this month, the FDA also granted SB-525 orphan drug status.
SB-525 uses an adeno-virus (AAV2/6) DNA human factor VIII construct. In preclinical studies, it appeared significantly more potent than equivalent constructs being evaluated for hemophilia A, and this treatment could allow clinically relevant levels of factor VIII protein to be reached using considerably lower doses.
“We believe SB-525 has the potential to be a best-in-class therapy that may provide patients with stable and durable levels of factor VIII protein with a single administration treatment,” Mikael Dolsten, MD, PhD, president of worldwide research and development at Pfizer, said in a press release.
“We believe Pfizer’s end-to-end gene therapy capabilities will enable comprehensive development and commercialization of SB-525, which could potentially benefit hemophilia A patients around the world,” added Sandy Macrae, PhD, Sangamo’s president and CEO.
Standard treatment for hemophilia A involves replacing the defective clotting factor with regular, frequent infusions of recombinant clotting factor or plasma concentrates.
Gene therapies potentially could transform treatment for hemophilia patients as a highly specialized, one-time treatment that targets the root cause of the disease. The technology involves introducing genetic material into the patient’s body to deliver a correct copy of a certain gene to compensate for a defective one. The genetic material can be delivered in many ways, but one of the most common is through a viral vector, such as rAAV.
Sangamo is planning to start a Phase 1/2 clinical trial (NCT03061201) soon to evaluate safety and to measure blood levels of factor VIII protein, as well as certain effectiveness endpoints.
Under the agreement, Sangamo gets an upfront $70 million payment from Pfizer and is responsible for conducting the SB-525 Phase 1/2 clinical study. Pfizer will be responsible for subsequent research, development or commercialization activities for SB-525. Other payments and responsibilities for each company are also included.