ACTG A randomized treatment-naive individuals to tenofovir-emtricitabine ( TDF/FTC) or abacavir-lamivudine (ABC/3TC) combined with efavirenz (EFV) or. This article reviews some of the differences in initial therapies for HIV infection. ACTG Shows Abacavir/lamivudine and Tenofovir/emtricitabine Provide Similar HIV Suppression at Low Viral Loads.
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First-line ART – ACTG A Study
We evaluated associations between week 4 VL change and time to virologic failure with Sctg proportional-hazards models. Smaller Week 4 viral load decline was associated with increased risk of virologic failure. Within acgt treatment arms, a less robust week 4 virologic response was associated with higher risk for subsequent virologic failure. However, between-regimen differences in week 4 VL declines did acty parallel the previously reported differences in longer term virologic efficacy in A, suggesting that between-regimen differences in responses were not due to intrinsic differences in antiviral activity.
The chronic phase of untreated HIV infection is characterized by viral replication resulting in atg dynamic equilibrium between viral production and clearance, with approximately one-half of the circulating virus replaced daily with newly produced virus. Most viral-dynamics models assume that ART results in complete inhibition of viral replication. If treatment has no effect on the death rate of infected cells or on the rate of plasma virus clearance, decay rates reflect the potency of 2502 in combination.
Thus, a comparison of early virologic response between different antiretroviral regimens may provide insights acg a regimen’s inherent antiviral activity, although antiretrovirals targeting different steps in the viral replication cycle may result in different decay rates independent of their antiviral activity.
Planned study duration was 96 weeks after qctg last subject enrolled. The study enrolled between and and completed follow-up in with a median length of follow-up of weeks.
The primary efficacy endpoint was time from acg to virologic failure. Actf viral load assessments prior to study entry were performed locally at each study site. From study entry onward, viral load assessments were performed centrally with the Roche Amplicor Monitor Assay Version 1.
All ACTG A subjects with an available week 4 viral load measurement were included in this analysis. To conserve sample aliquots for additional analyses, samples were diluted 1: We compared the viral load changes from entry to values obtained at Weeks 1, 2, and 4 between each of the four regimens using Wilcoxon rank sum tests. In the overall ACTG A study population, the relationship between change in viral load from entry to week 4 and time to virologic failure was evaluated with univariate and multivariable Cox proportional hazards models.
Approval was obtained from each participating sites’ institutional review board for the main study and the substudy. All subjects provided written informed consent prior to study entry. The enrolled subjects included in this analysis who returned for a Week 4 viral load assessment were 52002 to the overall study population of ACTG A Table 1.
In the early viral load substudy, subjects enrolled. Table 1 displays the baseline characteristics of these subjects. Baseline characteristics were balanced between subjects randomized to each of the four study regimens within the substudy data not shown. Patterns of viral load changes in the early viral load substudy mirrored the patterns observed in the overall study.
There was no evidence that this association differed by third drug assignment p-value for interaction of 0. In this protocol-specified secondary analysis of ACTG A and its viral load substudy, we found no significant difference in early viral load change between the NRTI arms, including in the high viral load stratum.
We found a smaller week 4 virologic response was associated with an increased risk for subsequent virologic failure. Our study results call into question the value of using early virologic response as a surrogate for expected longer term adtg outcome when comparing the efficacy of different regimens. Similarly, clinical trials that compare integrase inhibitor- to non-integrase inhibitor-based regimens invariably show a faster viral load decline in the integrase treatments, yet the ultimate study outcomes may be comparable.
Some limitations of this study should be noted. Subjects were not directly observed taking medication and baseline genotypes were not performed for all individuals in the study, possibly obscuring any potential 522 in regimen potencies; however, these limitations would presumably apply similarly across all randomized treatment arms.
Xctg association analysis is based on data collected post-randomization and restricted to those who were able to return for their Week 4 viral load sample. We did not separately assess 52202 relationship between week 4 virologic qctg and early or late virologic failure.
Additionally, for the early viral load substudy, the sample size was relatively small and we did not sample sufficient timepoints to calculate Phase 1 and Phase 2 decay rates.
Early virologic response to abacavir/lamivudine and tenofovir/emtricitabine during ACTG A
However, previous studies have shown that single early viral load measurements can be used as surrogates for the more complex sampling and modeling involved in estimating the phases zctg decay. In summary, we have shown that smaller four-week decline in viral load was associated with a higher rate of subsequent virologic failure.
Grant has received grant support from Bristol-Myers Squibb.
Tierney is a paid member of a Data Monitoring Committee for a Tibotec-sponsored hepatitis C drug study. National Center for Biotechnology InformationU. Author manuscript; available in PMC Jun DaarMD, 3 Paul E. SaxMD, 4 Ann C. CollierMD, 5 Margaret A. FischlMD, 6 Andrew R. Author information Copyright and License information Disclaimer. See other articles in PMC that cite the published article. Objective Compare regimen-specific early virologic response.
Conclusions Within all treatment arms, a less robust week 4 virologic response was associated with higher aftg for subsequent virologic failure. Time to Virologic Failure Analysis In the overall ACTG A study population, the relationship between change in viral load from entry to week 4 and time to virologic failure was evaluated with univariate and multivariable Cox proportional hazards models.
Early virologic response to abacavir/lamivudine and tenofovir/emtricitabine during ACTG A5202
Ethics Approval was obtained from each participating sites’ institutional review board for the main study and the substudy. Open in a separate window. Atazanavir plus ritonavir or efavirenz as part of a 3-drug regimen for initial treatment of HIV Annals of internal medicine. Abacavir-lamivudine versus tenofovir-emtricitabine for initial HIV-1 therapy. The New England journal of medicine. The Journal of infectious diseases. Journal of acquired immune deficiency syndromes Sep; 55 1: Panel on Antiretroviral Guidelines for Adults and Adolescents.
Guidelines for the use of antiretroviral agents in HIVinfected adults and adolescents.
Department of Health and Human Services. Antiretroviral therapy with the integrase inhibitor raltegravir alters decay kinetics of HIV, significantly reducing the second phase.
ACTG 5202 — Effectiveness of Different Treatments
Plasma HIV-1 RNA dynamics in antiretroviral-naive subjects receiving either triple-nucleoside or efavirenz-containing regimens: Relationship of plasma HIV-1 RNA dynamics to baseline factors and virological responses to highly active antiretroviral therapy in adolescents aged years infected through high-risk behavior.
Plasma HIV-1 RNA decline within the first two weeks of treatment is comparable for nevirapine, efavirenz, or both drugs combined and is not predictive of long-term virologic efficacy: Journal of acquired immune deficiency syndromes Mar 1; 38 3: Initial viral decay to assess the relative antiretroviral potency of protease inhibitor-sparing, nonnucleoside reverse transcriptase inhibitor-sparing, and nucleoside reverse transcriptase inhibitor-sparing regimens for first-line therapy of HIV infection.
Class-sparing regimens for initial treatment of HIV-1 infection. A Randomized Multicenter Trial. Internal medicine Tokyo, Japan ; 52 7: Once-daily dolutegravir versus raltegravir in antiretroviral-naive adults with HIV-1 infection: Safety and efficacy of raltegravir-based versus efavirenz-based combination therapy in treatment-naive patients with HIV-1 infection: Co-formulated elvitegravir, cobicistat, emtricitabine, and tenofovir versus co-formulated efavirenz, emtricitabine, and tenofovir for initial treatment of HIV-1 infection: Co-formulated elvitegravir, cobicistat, emtricitabine, and tenofovir disoproxil fumarate versus ritonavir-boosted atazanavir plus co-formulated emtricitabine and tenofovir disoproxil fumarate for initial treatment of HIV-1 infection: Determining the antiviral activity of tenofovir disoproxil fumarate in treatment-naive chronically HIVinfected individuals.