The comparative effectiveness of NRTI-sparing dual regimens in emulated trials using observational data from the Swiss HIV Cohort Study

BACKGROUND

Nucleoside (or nucleotide) reverse transcriptase inhibitors (NRTIs) cause side effects in some patients, prompting the use of either partly or fully NRTI-sparing regimens.

METHODS

We used data from the Swiss HIV Cohort Study to estimate the effectiveness of two new dolutegravir dual regimens relative to the alternative NRTI-sparing dual regimens that our clinicians used previously. We emulated two trials by propensity score matching case patients on the dolutegravir regimen with control patients on an alternative regimen. We analysed the case control sets using a Bayesian Cox model and estimated effectiveness as the percentage still on their trial regimen without virological failure at 48 weeks.

RESULTS

In a comparison of partly NRTI-sparing regimens, 58 cases treated with dolutegravir were matched to 17 controls treated with boosted darunavir (both with lamivudine or emtricitabine). The estimated difference in effectiveness was 15% (95% credible interval [CrI] 2-33) and 12% (95% CrI 0-26) in two sequential analyses 1 year apart. In a comparison of fully NRTI-sparing regimens, 54 cases treated with dolutegravir were matched to 32 controls treated with raltegravir (both with boosted darunavir). The estimated difference in effectiveness was 9% (95% CrI -1-21) and 5% (95% CrI -4-15) in the two sequential analyses.

CONCLUSIONS

Estimates of relative effectiveness suggest that both dolutegravir regimens are not inferior to these alternative regimens. All four regimens seem suitable for patients needing an NRTI-sparing regimen: there were few virological failures and few treatment changes due to toxicity.

Atazanavir/ritonavir with lamivudine as maintenance therapy in virologically suppressed HIV-infected patients: 96 week outcomes of a randomized trial

Objectives

To investigate the long-term safety and efficacy of a treatment switch to dual ART with atazanavir/ritonavir + lamivudine versus continuing a standard regimen with atazanavir/ritonavir + 2NRTI in virologically suppressed patients.

Methods

ATLAS-M is a 96 week open-label, randomized, non-inferiority (margin -12%) trial enrolling HIV-infected adults on atazanavir/ritonavir + 2NRTI, with stable HIV-RNA <50 copies/mL and CD4 counts >200 cells/mm3. At baseline, patients were randomized 1:1 to switch to atazanavir/ritonavir + lamivudine or to continue the previous regimen. Here, we report the 96 week efficacy and safety data. The study was registered with ClinicalTrials.gov, number NCT01599364.

Results

Overall, 266 subjects were enrolled (133 in each arm). At 96 weeks, in the ITT population, patients free of treatment failure totalled 103 (77.4%) with atazanavir/ritonavir + lamivudine and 87 (65.4%) with triple therapy (difference +12.0%, 95% CI +1.2/+22.8, P = 0.030), demonstrating the superiority of dual therapy. Two (1.5%) and 9 (6.8%) virological failures occurred in the dual-therapy arm and the triple-therapy arm, respectively, without development of resistance to any study drug. Clinical adverse events occurred at similar rates in both arms. A higher frequency of grade 3-4 hyperbilirubinemia (66.9% versus 50.4%, P = 0.006) and hypertriglyceridaemia (6.8% versus 1.5%, P = 0.031) occurred with dual therapy, although this never led to treatment discontinuation. A significant improvement in renal function and lumbar spine bone mineral density occurred in the dual-therapy arm. The evolution of CD4, HIV-DNA levels and neurocognitive performance was similar in both arms.

Conclusions

In this randomized study, a treatment switch to atazanavir/ritonavir + lamivudine was superior over the continuation of atazanavir/ritonavir + 2NRTI in virologically suppressed patients, with a sustained benefit in terms of improved renal function and bone mineral density.

Switching to dual antiretroviral regimens is associated with improvement or no changes in activation and inflammation markers in virologically suppressed HIV-1-infected patients: the TRILOBITHE pilot study

OBJECTIVES

While the use of dual antiretroviral therapies could reduce the toxicity of antiretroviral treatment in treatment-experienced HIV-1-infected patients, it is crucial to know if reducing the number of drugs could lead to an adverse increase in inflammation and activation markers.

METHODS

This was a cross-sectional pilot study conducted at the HIV-1 Unit at the Tertiary University Hospital in Madrid, Spain, evaluating biomarkers of activation [interferon-γ-induced protein 10 (IP10), high-sensitivity C-reactive protein (hs-CRP), soluble CD14 (sCD14) and sCD163], inflammation [interleukin-6 (IL-6)], blood coagulation (d-dimer), and immune response [interferon (IFN)-γ, tumour necrosis factor (TNF)-α and IL-4] in three groups of suppressed HIV-1-infected patients: patients continuing on triple therapy (26 patients), and patients who switched from triple to dual therapy, at 24 or 48 weeks after switching (13 and 36 patients, respectively).

RESULTS

Demographic and immunovirological parameters were similar in the three groups of patients. IL-6 and sCD14 levels were lower in patients at 48 weeks after switching to dual therapy compared with those found in patients who continued to receive triple therapy (P = 0.012 and P = 0.001, respectively), with no differences in the levels of the remaining biomarkers. Among patients with nadir CD4 count ≤ 200 cells/μL, sCD14 levels were lower in patients who had been on dual therapy for 48 weeks (14 patients) compared with those found in patients who received ongoing triple therapy (11 patients; P = 0.029), with no differences in the levels of the other biomarkers.

CONCLUSIONS

HIV-1-infected patients receiving dual regimens showed similar or even lower levels of inflammatory and activation markers compared with those found in patients who received ongoing triple therapy. Of note, similar data were obtained in patients with low nadir CD4 count.

No difference in effectiveness of treatment simplification to boosted or unboosted atazanavir plus lamivudine in virologically suppressed in HIV-1-infected patients

Background

Simplification strategies of antiretroviral treatment represent effective tools for the reduction of drug-induced toxicity, resistance mutations in case of virological failure and costs.

Objectives

To assess the effectiveness of simplification to atazanavir/ritonavir (ATV_rtv) or unboosted atazanavir (ATV₄₀₀) plus lamivudine, and if low plasma or intracellular ATV C_trough influence virological outcomes.

Methods

Ambispective observational study in patients with undetectable HIV-RNA who were switched to ATV_rtv or ATV₄₀₀ plus lamivudine once daily. Previous virological failures (VF) were allowed if the resistance tests showed major resistance mutation neither to ATV nor to lamivudine. VF was defined as two consecutive plasma HIV-RNA >200 copies/mL. Effectiveness was assessed by intention-to-treat and on-treatment analyses. Plasma and intracellular ATV C_trough were measured by LC-MS/MS.

Result

A total of 246 patients were included. At week 48, the Kaplan–Meier estimation of efficacy within the ATV_rtv and ATV₄₀₀ groups were 85.9% [95% confidence interval, (CI₉₅), 80.3–91.4%] versus 87.6% (CI₉₅, 80.1–94.1%) by intention-to-treat analysis (p = 0.684), and 97.7% (CI₉₅, 95.2–100%) versus 98.8% (CI₉₅, 97.0–100%) by on-treatment analysis (p = 0.546), respectively. Plasma and intracellular C_trough were significantly higher with ATV_rtv than with ATV₄₀₀ (geometric mean (GM), 318.3 vs. 605.9 ng/mL; p = 0.013) and (811.3 vs. 2659.2 ng/mL; p = 0.001), respectively. Only 14 patients had plasma C_trough below the suggested effective concentration for ATV (150 ng/mL). No relationship between plasma or intracellular C_trough and VF or blips were found.

Conclusion

Boosted or unboosted ATV plus lamivudine is effective and safe, and the lower plasma C_trough observed with ATV₄₀₀ do not compromise the effectiveness of these simplification regimens in long-term virologically suppressed HIV-1-infected patients.

Switching to abacavir versus use of a nucleoside-sparing dual regimen for HIV-infected patients with tenofovir-associated renal toxicity

OBJECTIVES

We investigated the reversibility of tenofovir disoproxil fumarate (TDF)-associated renal decline and tubular dysfunction using different antiretroviral strategies.

METHODS

A successive evaluation of renal [estimated glomerular filtration rate (eGFR)] and tubular (phosphataemia, proteinuria, albuminuria, phosphaturia, uricosuria, glycosuria and tubular proteinuria) parameters was performed in 231 patients, before and after switching from TDF to abacavir (n = 60), using dual therapy (n = 49), or continuing the same regimen including TDF (n = 122).

RESULTS

In a successive evaluation after a median of 8.86 months, or less time if treatment was switched (4.8 months vs. 13.3 months to second evaluation; P < 0.01), a significant improvement in eGFR (median change +0.3 vs. -2.91 mL/min/1.73 m2 in patients who did not discontinue TDF; P = 0.04) and tubular dysfunction (median change -40% vs. +30%, respectively; P < 0.01) was observed. Lineal regression showed that age (β = -0.14; P = 0.04), previous eGFR decline (β = -0.42; P < 0.01), and time on TDF (β = -0.19; P = 0.04) were associated with impaired eGFR recovery. There were no differences in eGFR slopes between patients using abacavir instead of TDF and those using a dual therapy, who showed similar improvement in proteinuria (-22% vs. -19%, respectively), phosphaturia (+10.1% vs. +9.4%, respectively), and urinary beta-2-microglobulin (-9% vs. -15%, respectively; P > 0.1 for all), although patients receiving the dual regimen were more heavily pretreated. A eGFR decrease (-6.17 mL/min/1.73 m2 ) was observed in patients taking dolutegravir or rilpivirine, but with similar improvement to that observed in the rest of switching patients in tubular abnormalities.

CONCLUSIONS

Tenofovir disoproxil fumarate discontinuation was associated with a rapid and significant improvement in eGFR and tubular abnormalities, regardless of whether abacavir or dual therapy was chosen. Switching to a regimen that included dolutegravir and/or rilpivirine was associated with a eGFR decrease without differences in the rate of tubular dysfunction improvement in comparison with the rest of patients who discontinued tenofovir.

Treatment simplification to atazanavir/ritonavir + lamivudine versus maintenance of atazanavir/ritonavir + two NRTIs in virologically suppressed HIV-1-infected patients: 48 week results from a randomized trial (ATLAS-M)

Background

Combination ART (cART)-related toxicities and costs have prompted the need for treatment simplification. The ATLAS-M trial explored 48 week non-inferior efficacy of simplification to atazanavir/ritonavir  +  lamivudine versus maintaining three-drug atazanavir/ritonavir-based cART in virologically suppressed patients.

Methods

We performed an open-label, multicentre, randomized, non-inferiority study, enrolling HIV-infected adults on atazanavir/ritonavir + two NRTIs, with stable HIV-RNA <50 copies/mL and CD4 + >200 cells/mm 3 . Main exclusion criteria were hepatitis B virus coinfection, past virological failure on or resistance to study drugs, recent AIDS and pregnancy. Patients were randomly assigned 1:1 to either switch to 300 mg of atazanavir/100 mg of ritonavir once daily and 300 mg of lamivudine once daily (atazanavir/ritonavir + lamivudine arm) or to continue the previous regimen (atazanavir/ritonavir + two NRTIs arm). The primary study outcome was the maintenance of HIV-RNA <50 copies/mL at week 48 of the ITT-exposed (ITT-e) analysis with switch = failure. The non-inferiority margin was 12%. This study is registered at ClinicalTrials.gov, number NCT01599364.

Results

Between July 2011 and June 2014, 266 patients were randomized (133 to each arm). After 48 weeks, the primary study outcome was met by 119 of 133 patients (89.5%) in the atazanavir/ritonavir + lamivudine arm and 106 of 133 patients (79.7%) in the atazanavir/ritonavir + two NRTIs arm [difference atazanavir/ritonavir + lamivudine versus atazanavir/ritonavir + two NRTIs arm: +9.8% (95% CI + 1.2 to + 18.4)], demonstrating non-inferiority and superior efficacy of the atazanavir/ritonavir + lamivudine arm. Virological failure occurred in two (1.5%) patients in the atazanavir/ritonavir + lamivudine arm and six (4.5%) patients in the atazanavir/ritonavir + two NRTIs arm, without resistance selection. A similar proportion of adverse events occurred in both arms.

Conclusions

Treatment simplification to atazanavir/ritonavir + lamivudine showed non-inferior efficacy (superiority on post-hoc analysis) and a comparable safety profile over continuing atazanavir/ritonavir + two NRTIs in virologically suppressed patients.