Sangamo Shows Early Promise Against HIV, Hemophilia at Gene Therapy Revival Meeting
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emergency use. “Those data were very well received, absolutely remarkable,” Lanphier says.
—One other Sangamo programs that caught attention at the conference was a treatment for HIV. This drug, SB-728, is designed to make it so T-cells of the immune system no longer produce a protein on their surface, called CCR5, which serves as a gateway for the HIV virus to infect and damage the immune system.
Data from nine patients in a Phase I clinical trial presented at the conference showed that the treatment appeared safe. More complete data on the first 18 patients in the trial is expected by the end of 2011, Lanphier says.
What’s interesting about this approach is that it works differently than the other one against hemophilia, which is directly injected into the body. In the case of HIV, blood is withdrawn from a patient, T-cells get filtered out in a common lab process, and those filtered cells get treated with Sangamo’s zinc-finger protein drug. The cells then get re-infused into the patient, where they resist HIV infection, and retain their ability to fight off the virus, Lanphier says. Data from this trial suggest that patients who got the re-infusion had an overall stronger immune defense than they did before, he says.
Pfizer already has an HIV drug on the market to block the CCR5 receptor, called maraviroc (Selzentry). But as Lanphier notes, the average T-cell has 1,000 to 2,000 of these receptors on the surface, and a healthy individual may have 100 billion T cells, so it’s thought to be pretty hard to get enough drug into the system to protect every cell. That’s one reason why researchers are hopeful about creating a process to treat those T-cells in an efficient process outside the body, and re-infuse them back into the patient, Lanphier says.