Predictors of the virological response to a change in the antiretroviral treatment regimen in HIV-1-infected patients enrolled in a randomized trial comparing genotyping, phenotyping and standard of care (Narval trial, ANRS 088)

Accumulated pre-switch resistance to more recently introduced one-pill-once-a-day antiretroviral regimens impacts HIV-1 virologic outcome

BACKGROUND

One-pill-once-a-day regimens (OPODs) appeal to providers and patients. The impact of resistance to OPODs in routine clinical care is important yet unclear, particularly in treatment-experienced patients.

OBJECTIVES

We hypothesized that resistance to any OPOD component impacts treatment success and that historical, vs. most recent, resistance better predicts it.

STUDY DESIGN

In the largest RI HIV Center, we identified all patients starting/switching to Complera/Stribild, evaluated their 12-month viral load (VL) suppression, and examined the impact of demographic, clinical and laboratory data on it, focusing on recent-only vs. accumulated significant resistance, defined as low-, intermediate- or high-level predicted resistance to any OPOD component. Associations with outcomes were evaluated using Fisher exact and Wilcoxon rank sum tests. Hypotheses were tested using logistic regression.

RESULTS

Of 1624 patients, 224 started/switched to Complera or Stribild, mean age 44 years, 8 years post-diagnosis, CD4 468 cells/μL; 183 treatment-experienced (140 with genotypes; 61% suppressed at switch). Significant OPOD-associated resistance was in 30% by recent-only genotypes, and 38% by all genotypes. 12-month VL suppression was in 83% of treatment-experienced participants: 96% of suppressed at switch, associated with older age, higher CD4, fewer prior genotypes, less accumulated resistance, and better adherence; and 61% of unsuppressed at switch, associated with better adherence. Accumulated resistance independently predicted 12-month failure, better than most-recent resistance only.

CONCLUSION

12-month VL suppression with Complera/Stribild was high, suggesting that OPODs remain options even for experienced patients. Clinicians should consider resistance history before switching to OPODs and continue to focus on improving adherence.

Genotypic susceptibility score (GSS) and CD4+ T cell recovery in HIV-1 patients with suppressed viral load

OBJECTIVES

HIV drug resistance, measured by the genotypic susceptibility score (GSS), has a deleterious effect on the virological outcome of HIV-1-infected patients. However, it is not known if GSS retains any predictive value for CD4 recovery in patients with suppressed viral load.

METHODS

Four hundred and six patients on virological failure (>500 copies/mL) with GSS  : <6 months prior to switch therapy who achieved undetectable plasma viral load (<50 copies/mL) within 1 year, remained undetectable >1 year on an unchanged regimen and had CD4 data available during entire follow-up were included. Adjusted and unadjusted analyses of all characteristics at switch related to CD4 recovery were made for three time frames: (i) 'switch-suppression'; (ii) 'suppression-1 year'; and (iii) 'switch-1 year'.

RESULTS

Higher GSS was associated with a greater CD4 recovery between 'switch' and '1 year' in the unadjusted analysis (P = 0.010); however, the effect of GSS was no longer statistically significant after adjusting for pre-switch clinical (CD4 count and plasma viral load) and demographic variables. Furthermore, only a lower pre-switch CD4 count was associated with increased CD4 recovery in the 'suppression-1 year' period in both unadjusted and adjusted models. The main CD4 recovery occurred in 'switch-suppression' and the variables associated, both unadjusted and adjusted, were CD4 and plasma viral load at switch, maintaining a trend for GSS (P = 0.06).

CONCLUSIONS

In individuals who re-suppressed HIV viraemia after switching therapy, regimens having a higher GSS were associated with improved CD4 recovery only during the period from switch to virological suppression, but, once viral load is re-suppressed, the GSS of the new regimen has no further effect on subsequent CD4 recovery.

Durability and Effectiveness of Maraviroc-Containing Regimens in HIV-1-Infected Individuals with Virological Failure in Routine Clinical Practice

INTRODUCTION

Limited data are available on the durability and effectiveness of maraviroc in routine clinical practice. We assessed the durability of maraviroc-containing regimens during a 30-month period, as well as their immunovirological and clinical efficacy, according to viral tropism in treatment-experienced individuals with viral load (VL) >50 copies/ml in the French Hospital Database on HIV.

METHODS

Virological success was defined as VL<50 copies/ml, immunological success as a confirmed increase of at least 100 CD4 cells/mm3 measured twice at least one month apart, and clinical failure as hospitalization for a non-AIDS event, an AIDS event, or death. Multivariable Cox regression models adjusted for potential confounders were used to assess the influence of viral tropism on durability, the immunovirological responses, and clinical outcome.

RESULTS

356 individuals started maraviroc with VL>50 copies/ml of whom 223 harbored R5 viruses, 44 non-R5 viruses and 89 viruses of unknown tropism. Individuals with non-R5 viruses were more likely than individuals with R5 viruses to discontinue maraviroc (75% vs 34%, p<0.0001). At 30 months, the estimated rates of virological and immunological success were respectively 89% and 51% in individuals with R5 viruses and 48% and 23% in individuals with non-R5 viruses. In multivariable analysis, non-R5 viruses were associated with a lower likelihood of both virological success (hazard ratio (HR): 0.42; 95% confidence interval (CI), 0.25-0.70) and immunological success (HR: 0.37; 95% CI, 0.18-0.77). No difference in clinical outcome was found between individuals with R5 and non-R5 viruses. The effectiveness of maraviroc-containing regimens in individuals with unknown viral tropism was not significantly different from that in individuals with R5 viruses. A limitation of the study is the absence of genotypic susceptibility score.

CONCLUSION

In this observational study, maraviroc-containing regimens yielded high rates of viral suppression and immunological responses in individuals with R5 viruses in whom prior regimens had failed.

IAPAC Guidelines for Optimizing the HIV Care Continuum for Adults and Adolescents

BACKGROUND

An estimated 50% of people living with HIV (PLHIV) globally are unaware of their status. Among those who know their HIV status, many do not receive antiretroviral therapy (ART) in a timely manner, fail to remain engaged in care, or do not achieve sustained viral suppression. Barriers across the HIV care continuum prevent PLHIV from achieving the therapeutic and preventive effects of ART.

METHODS

A systematic literature search was conducted, and 6132 articles, including randomized controlled trials, observational studies with or without comparators, cross-sectional studies, and descriptive documents, met the inclusion criteria. Of these, 1047 articles were used to generate 36 recommendations to optimize the HIV care continuum for adults and adolescents.

RECOMMENDATIONS

Recommendations are provided for interventions to optimize the HIV care environment; increase HIV testing and linkage to care, treatment coverage, retention in care, and viral suppression; and monitor the HIV care continuum.

HIV resistance testing and detected drug resistance in Europe

OBJECTIVES

To describe regional differences and trends in resistance testing among individuals experiencing virological failure and the prevalence of detected resistance among those individuals who had a genotypic resistance test done following virological failure.

DESIGN

Multinational cohort study.

METHODS

Individuals in EuroSIDA with virological failure (>1 RNA measurement >500 on ART after >6 months on ART) after 1997 were included. Adjusted odds ratios (aORs) for resistance testing following virological failure and aORs for the detection of resistance among those who had a test were calculated using logistic regression with generalized estimating equations.

RESULTS

Compared to 74.2% of ART-experienced individuals in 1997, only 5.1% showed evidence of virological failure in 2012. The odds of resistance testing declined after 2004 (global P < 0.001). Resistance was detected in 77.9% of the tests, NRTI resistance being most common (70.3%), followed by NNRTI (51.6%) and protease inhibitor (46.1%) resistance. The odds of detecting resistance were lower in tests done in 1997-1998, 1999-2000 and 2009-2010, compared to those carried out in 2003-2004 (global P < 0.001). Resistance testing was less common in Eastern Europe [aOR 0.72, 95% confidence interval (CI) 0.55-0.94] compared to Southern Europe, whereas the detection of resistance given that a test was done was less common in Northern (aOR 0.29, 95% CI 0.21-0.39) and Central Eastern (aOR 0.47, 95% CI 0.29-0.76) Europe, compared to Southern Europe.

CONCLUSIONS

Despite a concurrent decline in virological failure and testing, drug resistance was commonly detected. This suggests a selective approach to resistance testing. The regional differences identified indicate that policy aiming to minimize the emergence of resistance is of particular relevance in some European regions, notably in the countries in Eastern Europe.

Impact of Newly Available Drugs on Clinical Progression in Patients with Virological Failure after Exposure to Three Classes of Antiretrovirals

Objective

To study the prognosis of HIV-infected patients with virological failure after exposure to three classes of antiretroviral drugs (ARVs).

Design

Cohort study. Setting: French Hospital Database on HIV.

Patients

Patients previously exposed to at least two nucleoside reverse transcriptase inhibitors (NRTIs), two protease inhibitors and one non-NRTI, with viral load (VL) values of >5000 copies/ml after the exposure criteria were met and a new treatment initiated between 1998 and 2001 with VL >5000 copies/ml.

Main outcome measures

Risk of new AIDS-defining-events (ADEs) or death from first introduction of a drug never used before occurring between 1998 and 2001 defined as baseline.

Results

The main baseline characteristics of the 1092 patients were: previous ADE in 49% of cases, median CD4 cell count 181 μl, median VL 4.9 log10 copies/ml, median duration of ARV therapy 5.0 years and previous exposure to a median of nine ARVs. The crude progression rates were 20.1/100 patient-years among patients included in 1998, 15.1 in 1999, 11.1 in 2000 and 8.6 in 2001. After adjustment for baseline characteristics, the calendar year of inclusion was associated with the risk of clinical progression ( P<0.001). When the types of newly available drugs used at baseline or during follow-up were introduced into the model, year of inclusion was no longer associated with the risk of clinical progression ( P=0.42), while exposure to amprenavir/r, lopinavir/r, abacavir or tenofovir was associated with a lower risk.

Conclusions

The clinical prognosis of heavily pretreated patients experiencing virological failure improved between 1998 and 2001, mainly thanks to the use of newly available drugs with more favourable resistance profiles.

Current Status and Future Prospects of Therapeutic Drug Monitoring and Applied Clinical Pharmacology in Antiretroviral Therapy

The consensus of current international guidelines for the treatment of HIV infection is that data on therapeutic drug monitoring (TDM) of non-nucleoside reverse transcriptase inhibitors and protease inhibitors provide a framework for the implementation of TDM in certain defined scenarios in clinical practice. However, the utility of TDM is considered to be on an individual basis until more data are obtained from large clinical trials showing the benefit of TDM.

In April 2004, a panel of experts met in Rome, Italy. This followed an inaugural meeting in Perugia, Italy, in October 2000, which resulted in the article published in AIDS 2002, 16(Suppl 1):S5–S37. The objectives of this second meeting were to review the questions surrounding TDM of antiretroviral drugs and discuss the clinical utility, current concerns and future prospects of drug concentration monitoring in the care of HIV-1-infected individuals.

This report, which has been updated to include material published or presented at international conferences up to the end of September 2004, reviews pharmacokinetic and pharmacodynamic data and reports the issues discussed by the panel, offering advice to clinical care providers who may be currently, or are considering incorporating TDM into the routine care of their patients. In addition, the panel formulated a series of position statements that are relevant to the interpretation of current data and can aid the design of future clinical trials.

Part 2 of this Special article, Therapeutic drug monitoring and drug–drug interactions involving antiretroviral drugs, will be published in Antiviral Therapy 10(4).

Impact of Insertions in the HIV-1 P6 Ptapp Region on the Virological Response to Amprenavir

We evaluated the impact of genetic changes within p6Gag gene on the virological response (VR, mean decrease in plasma viral load at week 12) to unboosted amprenavir (APV). Gag-protease fragments, including gag p2, p7, p1, p6 regions and whole protease (PR) were sequenced from baseline plasma specimens of 84 highly pre-treated but APV-naive patients included in the NARVAL (ANRS 088) trial. The correlation between baseline p6Gag polymorphism, PR mutations, baseline characteristics and VR to APV was analysed in univariate analysis. Insertions (P459Ins) within p6 protein, leading to partial or complete duplication of the PTAPP motif, were significantly associated with a decreased VR (P459Ins versus wild-type; –0.3 ±0.8 vs –1.1 ±1.2 log copies/ml, P=0.007) and were more frequent when the V82A/F/T/S PR mutation was present ( P=0.020). In multivariate analysis, after adjustment on the predictive factors of the VR in the NARVAL trial and on the PR mutations linked with response, there was a strong trend to an association ( P=0.058) between the presence of P459Ins and an altered VR. In conclusion, these results suggest that insertions in the p6 region of HIV-1 gag gene may affect the VR, in highly pre-treated patients receiving an unboosted APV-containing regimen.