Salvage therapy with abacavir in HIV-1-infected patients with previously documented M184V mutation: a possibility of NRTI recycling

We evaluated in an open-label, randomized, controlled, pilot trial if the re-emergence of previously selected resistant strains, harbouring M184V mutation, could be modulated by the use of different drug associations as components of the new antiretroviral regimens. In addition, we assessed the clinical relevance of this mutation on the management of heavily pretreated HIV-infected patients. The primary end-point of the study was the reselection of M184V mutation. Secondary end-points were the variation over time of HIV RNA plasma levels and CD4 cell counts and the progression of HIV disease. The primary population for efficacy analysis was the intention-to-treat exposed population. After a run-in phase consisting in a new treatment regimen excluding either lamivudine (3TC) or abacavir (ABC) so as to clear the previously documented M184V mutation, 18 patients with an HIV RNA plasma level greater than 10000 copies/ml were randomized to receive an antiretroviral drug regimen (at least three drugs) including either ABC or the association of ABC+3TC. All patients were naive to ABC. The M184V mutation reappeared in 1/9 patients in the ABC group and in 8/9 patients in the ABC+3TC group (P