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Author:
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Llibre, Josep M.; Bravo, Isabel; Ornelas, Arelly; Santos, José R.; Puig, Jordi; Martín Iguacel, Raquel; Paredes, Roger; Clotet, Bonaventura
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Notes:
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Background
Switching subjects with persistently undetectable HIV-1 viremia under antiretroviral treatment
(ART) to once-daily tenofovir/emtricitabine (or lamivudine) + nevirapine is a cost-effective
and well-tolerated strategy. However, the effectiveness of this approach has not been
established.
Methods
We performed a retrospective study evaluating the rates of treatment failure, virological failure
(VF), and variables associated, in all subjects initiating this switch combination in our
clinic since 2001. Analyses were performed by a modified intention to treat, where switch
due to toxicity equalled failure. The main endpoint was plasma HIV-RNA < 50 copies/mL.
Results
341 patients were treated for a median of 176 (57; 308) weeks. At week 48, 306 (89.7%)
subjects had HIV-1 RNA <50 copies/mL, 10 (2.9%) experienced VF, and 25 (7.4%) discontinued
the treatment due to toxicity. During the whole follow-up 23 (6.7%) individuals (17 on
lamivudine, 6 on emtricitabine; p = 0.034) developed VF and treatment modification due to
toxicity occurred in 36 (10.7%). Factors independently associated with VF in a multivariate
analysis were: intravenous drug use (HR 1.51; 95%CI 1.12, 2.04), time with undetectable
viral load before the switch (HR 0.98; 0.97, 0.99), number of prior NRTIs (HR 1.49; 1.15,
1.93) or NNRTIs (HR 3.22; 1.64, 6.25), and previous NVP (HR 1.54; 1.10, 2.17) or efavirenz
(HR 5.76; 1.11, 29.87) unscheduled interruptions. VF was associated with emergence of
usual nevirapine mutations (Y181C/I/D, K103N and V106A/I), M184V (n = 16; 12 with lamivudine
vs. 4 with emtricitabine, p = 0.04), and K65R (n = 7).Conclusions
The rates of treatment failure at 48 weeks, or long-term toxicity or VF with this switch regimen
are low and no unexpected mutations or patterns of mutations were selected in subjects
with treatment failure. |
