Combinations of reverse transcriptase, protease, and integrase inhibitors can be synergistic in vitro against drug-sensitive and RT inhibitor-resistant molecular clones of HIV-1

Combinations of anti-HIV agents including one or two reverse transcriptase inhibitors with a protease inhibitor are potent and effective. However, toxicities, costs and the emergence of drug-resistant organisms have compromised their long-tel tn efficacy in people, A next, likely, target for anti-HIV therapy is HIV-1 integrase. Viral integration, catalyzed by integrase, is absolutely required for HIV replication. L-chicoric acid is a potent and selective inhibitor of HIV-1 integrase that also inhibits HIV-1 replication in cell culture. As a first step in understanding the potential role for integrase inhibitors in clinical medicine, the activities of L-chicoric acid alone and in combination with 2',3'-dideoxycytidine, zidovudine, and a protease inhibitor, nelfinavir, were tested in vitro against molecular clones of HIV-1 resistant to reverse transcriptase inhibitors. L-chicoric acid was equally effective against a wild-type clone of HIV-1, HIVNL4-3, or against HIV-1 resistant to either zidovudine or didroxycytidine. L-chicoric acid was largely synergistic with zidovudine and synergistic with both dideoxycytidine and nelfinavir. (C) 2000 Elsevier Science B.V. All rights reserved.