Two experimental antiretroviral drugs, called TMC278 and elvitegravir, show promise in controlling the viral loads of HIV-positive people who have developed resistance to available drugs, researchers said Wednesday at the 14th Annual Conference on Retroviruses and Opportunistic Infections in Los Angeles, the Los Angeles Times reports (Chong, Los Angeles Times, 3/1).
An estimated 40,000 HIV-positive people in the U.S. have developed resistance to available antiretrovirals and rely on a complex and changing combination of available drugs (Kaiser Daily HIV/AIDS Report, 2/28). One drug, developed by Johnson & Johnson subsidiary Tibotec and called TMC278, is a variation of a drug class called nucleoside reverse transcriptase inhibitors. The other antiretroviral, developed by Gilead and called elvitegravir, is an integrase inhibitor, which works by blocking an HIV enzyme called integrase, the Times reports (Los Angeles Times, 3/1). Integrase is one of the three enzymes necessary for HIV to replicate in the body, and integrase inhibitors would stop HIV from inserting its genes into uninfected DNA. The other two enzymes necessary for viral replication -- reverse transcriptase and protease -- already are targeted by a variety of antiretrovirals (Kaiser Daily HIV/AIDS Report, 2/28).
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