Abacavir/lamivudine/zidovudine maintenance after standard induction in antiretroviral therapy-naïve patients: FREE randomized trial interim results. A randomized trial of simplified maintenance therapy with abacavir, lamivudine, and zidovudine in human immunodeficiency virus infection. Impact of an educational program on efficacy and adherence with a twice-daily lamivudine/zidovudine/abacavir regimen in underrepresented HIV-infected patients.
Maintenance with a triple nucleoside reverse transcriptase Inhibitor (NRTI) regimen after successful induction with a dual NRTI/protease inhibitor (PI) combination may be advantageous, because of low pill burden, favorable lipids, and less drug interactions. This strategy to become free of PI-related problems without losing viral efficacy has not been formally tested. We performed a randomized, open-label, multicenter, 96-week comparative study in antiretroviral therapy (ART)-naïve patients with CD4 <or=350 cells/mm(3) and HIV-1 RNA concentrations (viral load [VL]) greater than 30,000 copies per milliliter. Patients were randomized after reaching VL less than 50 copies per milliliter on two consecutive occasions between 12 and 24 weeks after start of zidovudine/lamuvidine and lopinavir/ritonavir combination. Eligible subjects switched to abacavir/lamivudine/zidovudine (TZV) or continued the PI-containing regimen. Here we present the 48-week data with virologic success rate (failure: VL > 50 copies per milliliter). Two hundred seven patients had similar baseline (BL) characteristics: median CD4 180 cells/mm(3), median VL 5.19 log(10) copies per milliliter. One hundred twenty subjects (58%) met randomization criteria. Baseline VL differed significantly between dropouts and randomized subjects (median 5.41 versus 5.06 log(10) copies per milliliter, p = 0.017), as did CD4 cells (median 160 and 200 cells/mm(3), p = 0.044). Sixty-one subjects received TZV and 59 subjects continued NRTIs/PI. At week 48, 2 patients in the TZV group and 5 in the PI group did not have a sustained virologic suppression (log rank test; p = 0.379). CD4 counts increased significantly in both arms. In ART-naïve patients, TZV maintenance had similar antiviral efficacy compared to continued standard ART at 48 weeks after baseline. Patients on successful standard ART can be safely switched to a NRTI-only regimen, at least for the tested time period. This randomized study evaluated the efficacy and tolerability of continued treatment with protease inhibitor plus nucleoside-analogue combination regimens (n=79) or a change to the simplified regimen of abacavir-lamivudine-zidovudine (n=84) in patients with suppressed human immunodeficiency virus type 1 (HIV-1) RNA for > or = 6 months who did not have the reverse transcriptase 215 mutation. After a median follow-up of 84 weeks, virologic failure was 6% in the continuation and 15% in the simplified group (P=.081). Previous zidovudine monotherapy or dual therapy and archived reverse transcriptase resistance mutations in HIV-1 DNA at baseline were significant predictors of failure. Study treatment was discontinued because of adverse events in 20% of the continuation and 7% of the simplified group (P=.021). Simplification to abacavir-lamivudine-zidovudine significantly decreased nonfasting cholesterol and triglyceride levels; however, this switch strategy carries a risk of virologic failure when treatment history or resistance testing suggest the presence of archived resistance mutations to the simplified regimen. A 24-week open-label clinical trial was conducted in 195 HIV-infected adults commonly underrepresented in research (35% female, 71% African American, 21% Hispanic, and 20% injection drug users [IDUs]) to evaluate the effect of an HIV educational program on efficacy and adherence with a simple, compact, twice-daily triple nucleoside regimen containing a lamivudine (150 mg)/zidovudine (300 mg) combination (COM) tablet plus abacavir (ABC), 300 mg. At baseline, the patients' median plasma HIV-1 RNA level was 4.18 log10 copies/mL and the median CD4+ cell count was 379 cells/mm3. Patients were randomized 1:1 to 4 modules of the Tools for Health and Empowerment HIV education intervention plus routine counseling (EI + RC; n = 96) or to routine counseling alone (RC; n = 99). No differences between the EI + RC and RC treatment arms were observed with respect to the proportion of patients achieving plasma HIV-1 RNA levels <40 copies/mL (60% [33/55] vs. 55% [38/69]; P = 0.529) or <400 copies/mL (80% [44/55] vs. 80% [55/69]; P = 0.689) at week 24 (intent-to-treat observed analysis), increase in median CD4 cell count above baseline at week 24 (78.3 vs. 104.8 cells/mm3; P = 0.498), or mean overall adherence rates as measured by the Medication Event Monitoring System (MEMS) (70% vs. 74%). COM + ABC was generally well tolerated, and no association was observed between interruptions in treatment and the development of ABC hypersensitivity (5 suspected cases). In conclusion, in underrepresented patients, the EI used in this study did not affect the efficacy and adherence results with ABC + COM to any greater degree than did RC.
This review provides evidence that co-formulated abacavir-lamivudine-zidovudine remains a viable option for initiating antiretroviral therapy, especially in HIV-infected patients with pre-existing hyperlipidaemia. The varied geographical locations of the included trials augment the external validity of these findings. We are moderately confident in our estimate of the treatment effects of the triple NRTI regimen as initial therapy for HIV infection. In the context of the GRADE approach, such moderate quality of evidence implies that the true effects of the regimen are likely to be close to the estimate of effects found in this review; but there is a possibility that they could be substantially different.  Further research should be geared towards defining the subgroup of HIV patients for whom this regimen will be most beneficial.