Population Council Research that makes a difference

Laboratory scientists at the Population Council's Center for Biomedical Research (CBR) are developing water-based combination gels (two active agents) to block HIV infection in humans. The gels contain varying amounts of MIV-150 (an enzyme inhibitor that prevents infected cells from producing new virus) and zinc acetate (a broad-spectrum antiviral agent) in a base of carrageenan (a natural polymer isolated from seaweed).

Using an animal model of infection, the scientists have shown that PC-1005, a gel comprising carrageenan with 0.002% MIV-150 and 0.3% zinc acetate, completely blocks a modified form of HIV infection in monkeys for up to 24 hours after two weeks of daily gel application.

MIV-150 was originally developed as a potential HIV therapy by Medivir AB, which licensed the drug to the Council for development as a microbicide. In nonclinical tests conducted by Medivir and Chiron Corporation, and confirmed by Council scientists, MIV-150 has shown significant activity against HIV-1 primary isolates, mutants, and strains of HIV-1 that are resistant to other anti-HIV drugs. Extensive pharmacology and toxicology testing showed that MIV-150 is nontoxic in vitro and in vivo.

The scientists are now optimizing PC-1005 gels in terms of efficacy, safety, and stability. Once an optimized formulation is identified, the microbicide product development team will prepare clinical-grade material at CBR to support a Phase 1 clinical trial; clinical trials are studies performed with human subjects. Based on current progress, Phase 1 trials testing the MIV-150/zinc acetate gel versus the zinc acetate alone are projected to commence in early 2012.