Outcome of a second-line protease inhibitor-containing regimen in patients failing or intolerant of a first highly active antiretroviral therapy

The outcome of second-line protease inhibitor (PI)-containing highly active antiretroviral therapy (HAART) was investigated in 263 patients who were failed by (n = 148) or intolerant of (n = 115) a first HAART regimen. The endpoints were virologic failure (decline in HIV RNA < 1 log10 copies/ml after > or = 2 months) and discontinuation due to intolerance/toxicity. During a median follow-up of 483 days (33-1087 days), 154 patients (59%) discontinued the second regimen, 86 (33%) because of intolerance/toxicity; another 135 patients (51.3%) showed virologic failure. Independent factors associated with virologic failure (Cox's model) were 7 to 12 months of first HAART (hazard ratio [HR] 1.70 versus < or = 6 months: 95% confidence interval [CI], 1.08-2.70) and gender (HR 1.58 males versus females: 95% CI, 1.04-2.30); the negatively associated factors were advanced age (HR 0.61 > 34 years versus < or = 34 years: 95% CI, 0.42-0.88), a saquinavir-containing first HAART (HR 0.57 versus indinavir: 95% CI, 0.34-0.93) and change due to intolerance/toxicity (HR 0.58 versus failure: 95% CI, 0.35-0.98). The independent variables predictive of discontinuation due to intolerance/toxicity were the reason for switching (HR 1.79 intolerance versus failure: 95% CI, 1.02-3.16) and the first protease inhibitor (PI) regimen (HR 0.42 ritonavir versus indinavir: 95% CI, 0.22-0.80). Given that patients who are failed by a first regimen are at high risk of having rescue therapy fail as well, second-line regimens including therapies directed by testing of drug resistance patterns of clinical viral isolates are warranted. Patients experiencing toxicity due to a first PI-containing regimen are at risk of toxicity to other PIs and should be addressed to PI-sparing HAART.     

Antiretroviral Genotypic Resistance Mutations in HIV-1 Infected Korean Patients with Virologic Failure

Resistance assays are useful in guiding decisions for patients experiencing virologic failure (VF) during highly-active antiretroviral therapy (HAART). We investigated antiretroviral resistance mutations in 41 Korean human immunodeficiency virus type 1 (HIV-1) infected patients with VF and observed immunologic/virologic response 6 months after HAART regimen change. Mean HAART duration prior to resistance assay was 45.3±27.5 months and commonly prescribed HAART regimens were zidovudine/lamivudine/nelfinavir (22.0%) and zidovudine/lamivudine/efavirenz (19.5%). Forty patients (97.6%) revealed intermediate to high-level resistance to equal or more than 2 antiretroviral drugs among prescribed HAART regimen. M184V/I mutation was observed in 36 patients (87.7%) followed by T215Y/F (41.5%) and M46I/L (34%). Six months after resistance assay and HAART regimen change, median CD4+ T cell count increased from 168 cells/µL (interquartile range [IQR], 62-253) to 276 cells/µL (IQR, 153-381) and log viral load decreased from 4.65 copies/mL (IQR, 4.18-5.00) to 1.91 copies/mL (IQR, 1.10-3.60) (P<0.001 for both values). The number of patients who accomplished viral load <400 copies/mL was 26 (63.4%) at 6 months follow-up. In conclusion, many Korean HIV-1 infected patients with VF are harboring strains with multiple resistance mutations and immunologic/virologic parameters are improved significantly after genotypic resistance assay and HAART regimen change.     

Chinese pediatric highly active antiretroviral therapy observational cohort: a 1-year analysis of clinical, immunologic, and virologic outcomes

BACKGROUND: Few data are available on the outcomes of pediatric antiretroviral therapy (ART) in the developing world. METHODS: Eighty-three children were followed prospectively in China from July 2005 to August 2006 and received (zidovudine or stavudine) plus lamivudine plus (nevirapine or efavirenz). RESULTS: Fifty-one children were ART naive at enrollment, and 32 were ART experienced. After 12 months, median weight increased by 0.3 weight for age z-score, median CD4 count increased from 116 to 340 cells/mm (P < 0.0001), and median viral load decreased from 5.53 to <2.60 log10 copies/mL (P < 0.0001) in the previously ART-naive children. In the ART-experienced children, median CD4 count increased from 193 to 318 cells/mm (P = 0.13), despite little change in median viral load (4.85 to 4.58 log10 copies/mL; P = 0.83). The viral load was <400 copies/mL in 55% of the previously ART-naive children and in 16% of the ART-experienced children. CONCLUSIONS: Weight and CD4 cell counts improved, and more than half of previously ART-naive patients had undetectable viral loads at 1 year. Future efforts should focus on improved virologic suppression through improved adherence and access to second-line regimens.     

Randomized Controlled Trial of Once-Daily Tenofovir,Lamivudine, and Lopinavir/Ritonavir Versus Remaining on the Same Regimen in Virologically Suppressed HIV-Infected Patients on Their First PI-Containing HAART Regimen

Abstract

Purpose: To assess the effects of switching to once-daily (QD) lopinavir/ritonavir (LPV/r)-based combination therapy in HIV-infected patients who are virologically suppressed (HIV viral load <50 copies/mL) on their first protease inhibitor (PI)-containing regimen. Method: In this 48-week, prospective, open-label, randomized study, patients were either switched to once-daily LPV/r, tenofovir (TDF), and lamivudine (3TC) (QD arm) or remained on their existing regimen (control arm). The primary endpoint of the study was the proportion of patients maintaining virologic suppression following 48 weeks of treatment. Results: Fifty and 22 patients were randomized to the QD and control arms, respectively. At week 48, there was no significant difference in virological suppression between the QD and control arms using intent-to-treat (missing = failure) analysis (p = .44). There was no significant difference in discontinuation rates between the two arms (p = .66). Significantly more patients randomized to the QD arm reported gastrointestinal adverse events compared with the control arm (p = .009). There were no study drug-related serious adverse events. Conclusion: For patients who are already virologically suppressed on their first PI-containing regimen, switching to a QD regimen of TDF+3TC+LPV/r resulted in similar rates of virologic suppression when compared with staying on existing therapy.     

Antiretroviral treatment simplification with nevirapine in protease inhibitor-experienced patients with hiv-associated lipodystrophy: 1-year prospective follow-up of a multicenter, randomized, controlled study.

BACKGROUND: Simpler and less toxic antiretroviral strategies are needed to maximize treatment compliance without sacrificing potency, at least for drug-experienced HIV-infected patients currently on regimens containing protease inhibitors (PIs). Small nonrandomized studies have suggested a beneficial role of PI-sparing regimens on lipodystrophy. OBJECTIVES: To assess the virologic, immunologic, and clinical benefit of switching the PI to nevirapine in patients with HIV-associated lipodystrophy and sustained viral suppression before entry in the study. DESIGN: Open-labeled, prospective, randomized, multicenter study. SETTING: Seven reference inpatient centers for HIV/AIDS in Spain. PATIENTS: One hundred six HIV-infected adults with clinically evident lipodystrophy who sustained HIV-RNA suppression for at least 6 months with PI-containing antiretroviral combinations. INTERVENTION: Replacement of the PI with nevirapine during 48 weeks (Group A) versus continuing the prior PI (Group B). MEASUREMENTS: Several virologic and immunologic analyses, standard and specific biochemical tests, and anthropometric and dual X-ray absorptiometry measurements. RESULTS: At week 48, an HIV-1 RNA level <400 copies/ml was maintained in 79% and 77% of patients in Groups A and B, respectively, whereas 74% and 72% of patients had viral load levels <50 copies/ml. Absolute CD4+ counts significantly increased in both groups compared with baseline values, and a significant decrease in CD38+CD8+ cells was observed in Group A (p <.01) but not in group B. Overall, no significant changes in anthropometric or body shape measurements were found after 48 weeks. Fasting total cholesterol and triglyceride levels decreased in Group A (but not in Group B) compared with baseline values (p <.05), although no significant differences were seen between groups at the end of the study. Subjects in Group A reported a better quality of life (QOL) index than controls (p <.001), with the main reason reported being the greater simplicity of the new drug regimen. CONCLUSIONS: Protease inhibitor-sparing regimens, including nevirapine, seem to be an effective alternative for PI-experienced patients. Nevirapine-based triple therapies allow maintained control of HIV-1 RNA levels and improve the immunologic response at 48 weeks of follow-up in patients with prior sustained virologic suppression. The switch to nevirapine significantly improved the lipidic profile in Group A, although there were no differences between groups at the end of the study. Additionally, no significant changes were seen in terms of lipodystrophy-related body shape changes 1 year after the PI substitution. Finally, nevirapine-containing regimens have a simpler dosing schedule, and this facilitates high adherence and improves QOL.     

Efficacy and safety of a quadruple combination Combivir + abacavir + efavirenz regimen in antiretroviral treatment-naive HIV-1-infected adults: La Francilienne

OBJECTIVE: To evaluate the safety and efficacy of a protease inhibitor sparing, quadruple therapy (Combivir + abacavir + efavirenz) in antiretroviral treatment-naive HIV-1-infected adults. DESIGN: Multicenter open-label pilot study. Clinical and biological assessments were performed at baseline and at weeks 2, 4, 8, 16, 24, 32, 40, 48. RESULTS: Thirty-one subjects enrolled with a median baseline viral load (VL) of 4.69 log10 copies/mL and CD4 cell count of 322 cells/mm3. At week 48, 90% (intention-to-treat [ITT] switch included) and 77% (ITT switch = failure) patients had a VL <50 copies/mL. These results were similar in the population (n = 13) with a VL >100,000 copies/mL at baseline. Combivir + abacavir + efavirenz demonstrated an early antiretroviral response: 58% of patients had plasma HIV-1 RNA <50 copies/mL at week 8. Using a modified assay, the percentage of patients with VL <5 copies/mL at week 48 was 55% (17/31) and 42% (13/31) using ITT (switch included) and ITT (switch = failure), respectively. Median VL decreased by -4.0 log10 copies/mL at week 48 (ITT). Median CD4+ cell count change from baseline at week 48 was +129 cells/mm3 (ITT). Most patients experienced at least one drug-related adverse event that was not considered treatment-limiting by the investigator. There were no cases of abacavir hypersensitivity reactions. CONCLUSIONS: Safety and efficacy results from this study demonstrated that the quadruple regimen Combivir/abacavir/efavirenz is generally safe and displays potent and durable antiretroviral activity in antiretroviral treatment-naive HIV-1-infected patients, offering a promising therapeutic option in a PI-sparing strategy.     

Switching to a protease inhibitor-containing, nucleoside-sparing regimen (lopinavir/ritonavir plus efavirenz) increases limb fat but raises serum lipid levels: results of a prospective randomized trial (AIDS clinical trial group 5125s)

BACKGROUND: Subcutaneous limb fat loss continues to be one the most troubling side effects of long-term antiretroviral regimens. Nucleoside analogues and protease inhibitors (PIs) have been linked to the development of this complication. METHODS: We evaluated the effects of nucleoside-sparing and PI-sparing regimens on fat distribution, bone mineral density, and metabolic parameters in 62 subjects, who were not selected for lipoatrophy, with advanced HIV (nadir CD4 count or=80,000 copies/mL) and an undetectable HIV viral load. Participants were randomized to switch their initial successful antiretroviral regimen to open-label lopinavir/ritonavir (LPV/r) at a dose of 533/133 mg twice a day and efavirenz (EFV) at a dose of 600 mg/d (the nucleoside-sparing arm) versus EFV and 2 nucleoside analogues (the PI-sparing arm). FINDINGS: At week 48, the median change in limb fat in the nucleoside-sparing arm was 562 g (6%, interquartile range [IQR]: -218-1186 g) versus a loss of -242 g (-4%, IQR: -539-452 g) in the nucleoside-containing PI-sparing arm (P = 0.086). At the time of last observation (median = 102 weeks, IQR: 73-152 weeks), a median gain of 782 g (10%, IQR: -380-1168 g) of limb fat was noted in the nonnucleoside arm (n = 22) versus a loss of 850 g (-15%, IQR: -1270 to -526 g) in the nucleoside-containing arm (n = 25; P = 0.002). INTERPRETATION: The switch to a nucleoside-sparing combination antiretroviral regimen (LPV/r + EFV) was associated with significant improvement in limb fat. These results provide additional evidence that nucleoside analogues are important in the progressive limb fat loss that characterizes antiretroviral treatment and that switching medications can significantly improve this complication. This option has to be carefully balanced with the potential to increase serum lipid levels and the trend to increase virologic failure.     

Switch from enfuvirtide to raltegravir in virologically suppressed HIV-1 infected patients: Effects on level of residual viremia and quality of life

BackgroundRaltegravir is a potential treatment option for virologically suppressed HIV-1 infected patients on enfuvirtide with injection site reactions.ObjectivesTo characterize safety and efficacy of an enfuvirtide to raltegravir switch including changes in T-cells, quality of life, and residual viremia.Study designIn patients with viral load <50 copies/mL and injection site reactions, enfuvirtide was switched to raltegravir without additional changes to the antiretroviral regimen. Virologic failure was defined as a viral load >1000 copies/mL or two consecutive viral load measurements between 50 and 1000 copies/mL (low-level viremia). Over the 24 week study, we compared changes in T-cells, injection site reactions, quality of life, and residual viremia, as measured through the single-copy assay which can detect plasma virus down to a single copy, using paired t-tests.ResultsFourteen patients with a median CD4+ T-cell count of 420 cells/μL were enrolled. After the switch, two patients experienced virologic failure due to confirmed low-level viremia. However, both patients subsequently were re-suppressed, one without any changes to his regimen. There was no change in CD4+ T-cell count. Injection site reactions resolved. However, there was little reported change in quality of life. The baseline median level of residual viremia was 6 copies/mL and did not change after the switch to raltegravir.ConclusionsA switch to raltegravir in virologically suppressed patients on enfuvirtide is effective in maintaining immunologic and virologic control at 24 weeks but did not result in a change in residual viremia.     

Switch from enfuvirtide to raltegravir in virologically suppressed HIV-1 infected patients: Effects on level of residual viremia and quality of life

BackgroundRaltegravir is a potential treatment option for virologically suppressed HIV-1 infected patients on enfuvirtide with injection site reactions.ObjectivesTo characterize safety and efficacy of an enfuvirtide to raltegravir switch including changes in T-cells, quality of life, and residual viremia.Study designIn patients with viral load <50 copies/mL and injection site reactions, enfuvirtide was switched to raltegravir without additional changes to the antiretroviral regimen. Virologic failure was defined as a viral load >1000 copies/mL or two consecutive viral load measurements between 50 and 1000 copies/mL (low-level viremia). Over the 24 week study, we compared changes in T-cells, injection site reactions, quality of life, and residual viremia, as measured through the single-copy assay which can detect plasma virus down to a single copy, using paired t-tests.ResultsFourteen patients with a median CD4+ T-cell count of 420 cells/μL were enrolled. After the switch, two patients experienced virologic failure due to confirmed low-level viremia. However, both patients subsequently were re-suppressed, one without any changes to his regimen. There was no change in CD4+ T-cell count. Injection site reactions resolved. However, there was little reported change in quality of life. The baseline median level of residual viremia was 6 copies/mL and did not change after the switch to raltegravir.ConclusionsA switch to raltegravir in virologically suppressed patients on enfuvirtide is effective in maintaining immunologic and virologic control at 24 weeks but did not result in a change in residual viremia.     

ABCB1 Allele Polymorphism Is Associated with Virological Efficacy in Naïve HIV-Infected Patients on HAART Containing Nonboosted PIs But Not Boosted PIs

Abstract

Objective: To assess the effect of the multidrug resistance-1 single nucleotide polymorphism (ABCB1 SNP) C3435T in exon 26 on the virological responses to first-line protease inhibitor (PI)-containing HAART regimens. Method: A cohort of 182 HIV-infected patients with a PI-containing HAART regimen initiated from 1997 to 2004 was enrolled. Time to the first indetectable viral load (VL) was determined in patients with the CC, CT, or TT genotype. Results: There were 37%, 44%, and 19% of patients who had the CC, CT and TT genotypes, respectively. The median estimated times to VL indetectability in the CC, CT, and TT groups were respectively 5.9, 3.9, and 4.8 months (p = .06). In patients on a non-boosted PI regimen, ABCB1 genotype was associated with time to VL indetectability that was shorter in patients with the CT than CC genotype (CT vs. CC, hazard ratio [HR] = 0.62, p = .02; TT vs. CC, HR = 0.72, p = .21). This association was not found in patients with first-generation boosted PI-containing regimens and especially not with second-generation boosted PI-containing regimens. Conclusion: Our results show that the ABCB1 SNP in exon 26 is associated with virological efficacy in HIV-infected patients treated with non-boosted PI-containing regimens but not with those containing boosted PIs, particularly of the second generation.