Pfizer announced that the U.S. Food and Drug Administration (FDA) has granted full approval to Pfizer’s HIV entry inhibitor, Selzentry (maraviroc), for treatment-experienced patients. Selzentry had previously been granted accelerated approval, with full approval conditional upon longer-term efficacy and safety data, which Pfizer has now provided.

Selzentry works by blocking HIV from functionally attaching to CCR5 receptors on CD4 cells. Because HIV can evolve to use another receptor, called CXCR4, a tropism test is necessary before starting Selzentry to determine which receptor a person’s HIV uses. The FDA recommends that Selzentry be taken only by people whose HIV uses CCR5.