Bottles containing the anti-HIV medication T-1249 developed by the Trimeris Biopharmaceutical Company. T-1249 is in a category of HIV medicines called fusion inhibitors, or entry inhibitors. Entry inhibitors are a new class of anti-HIV drugs none of which have yet been approved for the treatment of HIV. T-1249 binds to a protein on HIV's surface called gp41. Once this occurs, HIV cannot bind with the surface of T-cells, thus preventing the virus from infecting healthy cells.