Pfizer Inc. and the International Partnership for Microbicides are announcing a collaborative effort to determine whether a newly approved HIV drug can be reformulated to prevent transmission of the virus. The New York drug maker will license Selzentry to IPM with the goal of turning it into an HIV-blocking vaginal ring, gel or film.
Some medicines are used to both prevent and treat diseases such as tuberculosis and malaria, and there is hope that existing HIV drugs can somehow do the same. However, HIV preventives have thus far proved elusive. The collaboration offers a low-risk way for Pfizer to find out if Selzentry could become a frequently taken drug, while potentially offering an empowering option to women in the developing world.
Selzentry was approved last year for treatment-experienced HIV patients. The drug already has a safety portfolio approved by the Food and Drug Administration, meaning it could make it through testing easier in a new form. And the way Selzentry works, by blocking HIV from infecting healthy cells, could make it a better candidate for prevention than medicines that prevent already-diseased cells from replicating.
Because Selzentry interrupts HIV's ability to penetrate a healthy cell at the CCR5 entry point, it is only approved for patients who have one strain of the virus. But that receptor is the primary one responsible for HIV transmission, said John Mellors, chief of infectious diseases at the University of Pittsburgh's School of Medicine, who has done consulting work with IPM.
Jack Watters, Pfizer's vice president for external medical affairs, is optimistic about Selzentry's prospects as a preventative therapy, but he cautioned: "We're a long way from proving that."
01/30/08
GLOBAL: Pfizer Seeks to Prevent HIV
Source: Wall Street Journal:: Avery Johnson; Courtesy of the CDC National Center for HIV, STD, and TB Prevention