Objectives: In the context of simplification strategies, it is essential to know the feasibility of a switch to a rilpivirine-based therapy. The aim of this study was to describe rilpivirine, tenofovir and emtricitabine resistance in HIV-1-infected patients who experienced virological failure during their previous antiretroviral treatment.
Patients and methods: The studied population included two groups of patients, all rilpivirine naive, tested for resistance by bulk sequencing from 2008 to 2011: the first group (n = 998) failing a nucleoside reverse transcriptase inhibitor (NRTI) plus boosted protease inhibitor (PI)-based regimen and the second group (n = 3733) failing an NRTI plus non-nucleoside reverse transcriptase inhibitor (NNRTI)-based regimen.
Results: In the first group, the frequency of rilpivirine mutations and resistance to rilpivirine (5.1%) was similar to that in antiretroviral-naive HIV-1-infected patients. Among the 1605 patients from the second group with at least one NNRTI mutation in their HIV, the prevalence of viruses 'resistant' or 'possibly resistant' to efavirenz, nevirapine and etravirine was 78%, 79% and 74%, respectively, while 59% were resistant to rilpivirine. Resistance to rilpivirine was significantly more frequent in non-B subtype versus B subtype viruses. Among pretreated patients with viruses with at least one NNRTI mutation (other than for rilpivirine), 22% of sequences were susceptible to the combination rilpivirine/emtricitabine/tenofovir disoproxil fumarate.
Conclusions: In patients failing an NRTI plus NNRTI-based regimen, to know the feasibility of a switch to rilpivirine/emtricitabine/tenofovir disoproxil fumarate, reliable resistance information should be available at the time of use of concurrent NNRTI therapy.
Keywords: non-nucleoside reverse transcriptase inhibitors; resistance mutations; retroviruses.