Predictors of loss of virologic response in subjects who simplified to lopinavir/ritonavir monotherapy from lopinavir/ritonavir plus zidovudine/lamivudine

Predictors of virological failure in HIV-1-infected patients switching to dolutegravir maintenance monotherapy

Objectives

The Dolutegravir Monotherapy for HIV (DOMONO; NCT02401828) study showed that maintenance monotherapy with dolutegravir (DTG) is associated with virological failure (VF) and leads to DTG resistance and as a result should not be used. However, data on clinical and virological factors associated with VF during DTG monotherapy are lacking. We identified factors associated with VF during DTG monotherapy.

Methods

A randomized trial was carried out in which patients on combination antiretroviral therapy (cART) with an HIV‐1 RNA zenith < 100 000 copies/mL and a CD4 T‐cell nadir ≥ 200 cells/μL, who had never experienced VF, switched to DTG monotherapy. Clinical and virological factors were compared between patients with and without VF, using univariate analyses.

Results

Eight of the 95 patients developed VF during DTG monotherapy. A total of 78 participants had reached week 48 when the study was discontinued. The median CD4 T‐cell nadir was lower in patients with VF than in patients without VF [260 (interquartile range (IQR) 223–320) versus 380 (IQR 290–520) cells/μL, respectively; P = 0.011]. Patients with VF had a longer time between HIV diagnosis and cART initiation than those without VF [median 49 (IQR 27–64) versus 15 (IQR 1–38) months, respectively; P = 0.015]. The median total peripheral blood mononuclear cell (PBMC) HIV DNA copy number was higher in patients with VF than in those without VF [417 (range 85–4151) versus 147 (range 16–4132) copies/10⁶PBMCs, respectively; P = 0.022].

Conclusions

A lower CD4 nadir, a longer time between HIV diagnosis and cART initiation, and a higher HIV DNA copy number at the time of DTG monotherapy initiation were associated with VF. While there clearly is no future role for DTG monotherapy, ongoing and future studies on the efficacy of maintenance dual therapy (e.g. DTG lamivudine) may have to take these variables into account in their study design and analysis.

Switch strategies in antiretroviral therapy regimens

Despite great advances in antiretroviral therapy in the last decade, several limitations still remain such as adverse effects, lack of adherence and drug-drug interactions. Switching antiretroviral therapy in stable, virologically suppressed patients with the aim of improving tolerability and convenience is an expanding strategy in clinical practice. Several factors need to be taken into consideration when switching a suppressive regimen, such as previous virologic failure, genetic barrier of the new regimen, prior duration of virologic suppression and expected level of adherence. The most frequently used strategies include reductions in the number of pills, drugs or doses. Although switching strategies may be useful, not all the regimens used in clinical practice are based on data from randomized clinical trials and some may not be the best option for certain patients; therefore, therapy should be individualized taking into consideration available information as well as patient and drug characteristics.

Lopinavir plasma concentrations and virological outcome with lopinavir-ritonavir monotherapy in HIV-1-infected patients

There is significant intra- and intersubject variability in lopinavir (LPV) plasma concentrations after standard dosing; thus, this prospective study was conducted to determine whether low plasma LPV concentrations could be associated with virological outcome throughout lopinavir-ritonavir maintenance monotherapy (mtLPVr) in the clinical practice setting. If this hypothesis would be confirmed, LPV drug monitoring could improve the efficacy of mtLPVr regimens. Patients with previous virological failure (VF) on protease inhibitor-based regimens were also included if the genotypic resistance tests showed no major resistance mutation associated with reduced susceptibility to lopinavir-ritonavir. VF was defined as 2 consecutive determinations of HIV RNA levels of >200 copies/ml. Efficacy was analyzed by per-protocol analysis. Plasma LPV trough concentrations were measured by high-performance liquid chromatography using a UV detector. A total of 127 patients were included (22% with previous failure on protease inhibitors). After 96 weeks, the efficacy rate was 82.3% (95% confidence interval [CI(95)], 75.3 to 89.3%). Virological efficacy was independent of LPV plasma concentrations even when LPVr was given once daily. An adherence of <90% (HR, 4.4 [CI(95), 1.78 to 10.8; P = 0.001]) and the presence of blips in the preceding 12 months (HR, 3.06 [CI(95), 1.17 to 8.01; P = 0.022]) were the only variables independently associated with time to VF. These findings suggest that the LPV concentrations achieved with the standard doses of LPVr are sufficient to maintain virological control during monotherapy and that measurement of LPV concentrations is not useful for predicting virological outcome. Tight control of viral replication in the previous months and strict adherence throughout the mtLPVr regimen could improve the virological efficacy of this maintenance regimen.

Long-term lopinavir/ritonavir monotherapy in HIV-infected children

BACKGROUND

Long-term data are limited on lopinavir/ritonavir monotherapy (mLPV/r) as a treatment simplification strategy in virologically suppressed children.

METHODS

Children with confirmed plasma HIV viral load (VL) <50 copies/mL while receiving double protease inhibitors (dPI) were switched to mLPV/r therapy. Virologic failure (VF) was defined as 2 consecutive VL ≥ 500 or 3 consecutive VL ≥ 50 copies/mL. dPI was resumed within 4 weeks in children with VF. Primary endpoint was the proportion of children with VL < 50 copies/mL while still receiving mLPV/r at week 144.

RESULTS

Forty children were enrolled; 90% were receiving LPV/r + saquinavir and 10% LPV/r + indinavir before simplifying to mLPV/r. Median age was 11.7 years; 50% were female. Median CD4% was 27%. Four (10%) had VL > 50 copies/mL at entry. At week 144, the proportion of children still receiving mLPV/r who had VL < 50 copies/mL was 22 of 40 (55%). The proportion of all children with VL < 50 copies/mL at week 144 was 33 of 40 (82.5%). Among 16 children who had VF and resumed dPI, 11 (69%) achieved VL < 50 copies/mL at week 144. No children with VF had major LPV/r mutations. Having detectable VL at entry and adherence by pill count <95% for >3 times at any visits during the study period significantly predicted VF on mLPV/r (both P = 0.025). The proportion of children with elevated total cholesterol (>200 mg/dL) decreased from 65% at baseline to 40% at week 144 (P = 0.007).

CONCLUSIONS

About half of children maintained virologic suppression on mLPV/r for almost 3 years. VF was common but the majority achieved suppression after resuming dPI and none had major LPV/r mutations. mLPV/r should only be considered for simplified maintenance therapy if frequent VL monitoring to detect VF is available.

Boosted protease inhibitor monotherapy in HIV-infected adults: outputs from a pan-European expert panel meeting

While the introduction of combination highly active antiretroviral therapy (HAART) regimens represents an important advance in the management of human immunodeficiency virus (HIV)-infected patients, tolerability can be an issue and the use of several different agents may produce problems. The switch of combination HAART to ritonavir-boosted protease inhibitor (PI) monotherapy may offer the opportunity to maintain antiviral efficacy while reducing treatment complexity and the risks of toxicity. Current European AIDS Clinical Society (EACS) guidelines recognise ritonavir-boosted PI monotherapy with twice-daily lopinavir/ritonavir or once-daily darunavir/ritonavir as a possible option in patients who have intolerance to nucleoside reverse transcriptase inhibitors, or for treatment simplification. Clinical trials data for PI boosted monotherapy are encouraging, showing substantial efficacy in the majority of patients; however, further data are required before this approach can be recommended as a routine treatment. Available data indicate that the most suitable candidates for the use of boosted PI monotherapy are long-term virologically suppressed patients who have demonstrated good adherence to antiretroviral therapy, who do not have chronic hepatitis B, have no history of treatment failure on PIs and are able to tolerate low-dose ritonavir.

A randomized comparison of second-line lopinavir/ritonavir monotherapy versus tenofovir/lamivudine/lopinavir/ritonavir in patients failing NNRTI regimens: the HIV STAR study

BACKGROUND

Data informing the use of boosted protease inhibitor (PI) monotherapy as second-line treatment are limited. There are also no randomized trials addressing treatment options after failing first-line non-nucleoside reverse transcriptase inhibitor (NNRTI)-regimens.

METHODS

HIV-infected subjects ≥18 years, with HIV RNA≥1,000 copies/ml while using NNRTI plus 2 NRTIs, and naive to PIs were randomized to lopinavir/ritonavir (LPV/r) 400/100 mg twice daily monotherapy (mono-LPV/r) or tenofovir disoproxil fumarate (TDF) once daily plus lamivudine (3TC) twice daily plus LPV/r 400/100 mg twice daily (TDF/3TC/LPV/r) at nine sites in Thailand. The primary outcome was time-weighted area under curve (TWAUC) change in HIV RNA over 48 weeks. The a priori hypothesis was that the mono-LPV/r arm would be considered non-inferior if the upper 95% confidence limit in TWAUC mean difference was ≤0.5 log(10) copies/ml.

RESULTS

The intention-to-treat (ITT) population comprised 195 patients (mono-LPV/r n=98 and TDF/3TC/LPV/r n=97): male 58%, baseline mean (sd) age of 38 (7) years, CD4(+) T-cell count of 204 (135) cells/mm(3) and HIV RNA of 4.1 (0.6) log(10) copies/ml. The majority had HIV-1 recombinant CRF01_AE infection, and thymidine analogue mutation (TAM)-2 was 3× more common than TAM-1. At 48 weeks, the difference in TWAUC HIV RNA between arms was 0.15 (95% CI -0.04, 0.33) log(10) copies/ml, consistent with our definition of non-inferiority. However, the proportion with HIV RNA<50 copies/ml was significantly lower in the mono-LPV/r arm: 61% versus 83% (ITT, P<0.01). Baseline HIV RNA≥5 log(10) copies/ml (P<0.001) and mono-LPV/r use (P=0.003) were predictors of virological failure. Baseline genotypic sensitivity scores ≥2 and TAM-2 were associated with better virological control in subjects treated with the TDF-containing regimen.

CONCLUSIONS

In PI-naive patients failing NNRTI-based first-line HAART, mono-LPV/r had a significantly lower proportion of patients with HIV RNA<50 copies/ml compared to the TDF/3TC/LPV/r treatment. Thus, mono-LPV/r should not be recommended as a second-line option.

Monoboosted lopinavir/ritonavir as simplified second-line maintenance therapy in virologically suppressed children

BACKGROUND

Monoboosted protease inhibitor is being evaluated as a strategy to simplify therapy in virologically suppressed patients who are on complex regimens.

METHODS

Children with two consecutive HIV-RNA below 50 copies/ml at least 3 months apart while on double boosted protease inhibitor (dPI) were switched to monoboosted lopinavir/r (mLPV/r). The previous dPI regimen was resumed within 4 weeks in children who experienced virological failure defined as two HIV-RNA at least 500 or three HIV-RNA at least 50 copies/ml. Primary endpoint was the proportion of children still on mLPV/r and having HIV-RNA less than 50 copies/ml at week 48.

RESULTS

Forty children on LPV/r + saquinavir (90%) or LPV/r + indinavir (10%) were enrolled, 50% were female, median [interquartile range (IQR)] age was 11.7 (10.2-13.5) years, and body weight was 29.4 (24.1-40.2 kg). The median (IQR) CD4% was 27 (23.5-29.5%). At 48 weeks, none had died or had HIV disease progression. Thirty-one children were on mLPV/r and 29 (72.5%) had HIV-RNA less than 50 copies/ml. Nine resumed dPI due to mLPV/r failure with four achieving undetectable HIV-RNA. Overall, 31 children (82.5%) had HIV-RNA suppression. Predicting factor for failing mLPV/r was baseline HIV-RNA at least 50 copies/ml. No major protease mutations were found.

CONCLUSION

By simplifying second-line treatment from dPI to mLPV/r, the majority of children had sustained viral suppression at 48 weeks. Randomized study of simplified mono protease inhibitor therapy in children is warranted.

[Meta-analysis of the effectiveness of the strategy of monotherapy with boosted protease inhibitors in HIV+ patients]

INTRODUCTION

The objective of this study is to analyse the available evidence regarding the effectiveness of the strategy of induction maintenance with boosted protease inhibitors with ritonavir in adult HIV patients as compared to conventional treatment.

METHODS

We performed a meta-analysis of randomised controlled trials in HIV patients to compare the efficacy of a monotherapy strategy of boosted protease inhibitors as compared with conventional antiretroviral therapy. The literature search was conducted in PubMed, EMBASE (September 1999-September 2009) and in conference abstracts of the last 5 years. The Odds Ratio of treatment failure and their 95% confidence intervals were calculated. To combine the results of individual studies selected, a fixed effects model based on the Mantel-Haenszel method or random effects was used, depending on whether or not the results were heterogeneous.

RESULTS

Initially a total of 1510 publications were found, of which just 8 studies met the criteria for inclusion in the meta-analysis. The combined Odds Ratio of the 8 studies is 1.39 (95% CI 1.02-1.90) for the treatment group with conventional antiretroviral treatment, but with a confidence interval close to the limits of statistical non-significance.

CONCLUSION

The results of the combined effectiveness analysis in the meta-analysis found no significant differences between the conventional strategy and monotherapy. This strategy is considered recommended (level A evidence) in patients with no history of previous failure of protease inhibitor, with undetectable plasma viral load and signs or symptoms of nucleoside/nucleotide toxicity.