Long-term virological outcome in patients infected with multi-nucleoside analogue-resistant HIV-1.

The emergence of HIV strains that are resistant to antiretroviral drugs is a major cause of treatment failure. Two sets of mutations: the Q151 M complex and the 69 insert, cause resistance to multiple nucleoside analogues. We report the response to treatment in 12 patients with multiple NRTI-resistant HIV-1 strains. Seven of 12 patients (58%) were able to maintain a viral load below 200 copies/ml at week 48. The patients most likely to obtain therapeutic success were those having no or low-level resistance to non-nucleoside reverse transcriptase inhibitors and/or protease inhibitors. New and more effective drugs are needed for patients with HIV-1 that is resistant to more than one of the current three classes of HIV drugs.