Dolutegravir-based dual maintenance regimens combined with lamivudine/emtricitabine or rilpivirine: risk of virological failure in a real-life setting

Sex differences in the effectiveness and tolerability of dolutegravir plus rilpivirine as a switch strategy in people living with HIV

INTRODUCTION

Dolutegravir + rilpivirine (DTG + RPV) is an effective antiretroviral therapy regimen approved in clinical guidelines as a switch therapy for virologically suppressed people with HIV. Our study aimed to compare the effectiveness and tolerability of DTG + RPV in women and men in real-world clinical practice.

METHODS

This was a retrospective analysis of treatment-experienced people with HIV from a large HIV unit who switched to DTG + RPV. We analysed treatment effectiveness, rates of adverse events and discontinuation, and metabolic changes after 48 weeks of treatment. HIV-RNA levels <50 copies/mL were analysed at 48 weeks using both intention-to treat analysis (where missing data were interpreted as failures) and per-protocol analysis (excluding those with missing data or changes due to reasons other than virological failure). Outcomes were compared between women and men based on sex at birth.

RESULTS

A total of 307 patients were selected (71 women and 236 men). No transgender people were included. At baseline, women had lived with HIV infection and received antiretroviral therapy for longer than men (23.2 vs 17.4 years and 18.9 vs 14.2 years, respectively). In the intention-to-treat analysis, 74.6% (95% confidence interval [CI] 63.4-83.3%) of women and 83.5% (95% CI 78.2-87.7) of men had HIV-RNA <50 copies/mL. In the per-protocol analysis, 96.4% (95% CI 87.7-99) of women and 99% (95% CI 98.9-99.7) of men had HIV-RNA levels <50 copies/mL. Two women and two men had HIV-RNA >50 copies/mL at 48 weeks. Discontinuation due to adverse events was more frequent in women than in men: 12.7% vs 7.2% (p < 0.02). Neuropsychiatric and gastrointestinal events were the most frequently reported. A median (interquartile range) weight gain of 1.9 kg (0-4.2) in women and 1.2 kg (-1-3.1) in men was reported (median of differences between baseline visit and week 48); the remaining changes in metabolic parameters were neutral.

CONCLUSIONS

DTG + RPV exhibited good and similar virological effectiveness in women and men in real-world settings. However, poorer tolerability and more treatment interruptions were observed in women.

Real-world prevalence of integrase inhibitor resistance and virological failure since adoption as guideline-preferred therapy

Background

Limited data reporting real-world prevalence of integrase strand transfer inhibitor resistance (INSTI-R) in the USA are available because their recommendation as first-line treatment in 2017. Reported national surveillance data in the USA estimated INSTI-R to be 6.3% as of 2018. This article aims to describe estimated prevalence of INSTI-R within a single clinic network in Chicago, IL, USA, and identify risk factors for resistance and virological failure (VF).

Methods

This was a retrospective, single-centre study of adults with HIV starting an INSTI-containing regimen between September 2017 and 2020. The primary endpoint was the difference in INSTI-R of the sample population compared with the national prevalence. Other outcomes included VF and documented INSTI-R mutations.

Results

Of 948 participants screened, 321 were included. Eight people had baseline INSTI-R testing results available, of which five had INSTI-R at baseline for an estimated prevalence of 1.6%. This estimation was significantly less than the national estimated prevalence of 6.3% (p<0.001). VF occurred in 26 (7.8%) individuals. Because no participants acquired INSTI-R during the study period, investigators were unable to identify risk factors associated with the development of INSTI-R. People with high pre-treatment viral loads had 1.21 (95% CI 1.05-1.39) higher odds of VF.

Conclusions

Amongst participants on INSTI-containing regimens, INSTI-R rates were estimated to be lower than the estimated national prevalence. Detectable pre-switch viral loads were more associated with VF than undetectable viral loads.

Therapeutic drug monitoring and virological response at week 48 in a cohort of HIV-1-infected patients switching to dolutegravir/rilpivirine dual maintenance therapy (ANRS-MIE-BIRIDER study)

AIMS

Dolutegravir (DTG) and rilpivirine (RPV) dual therapy is now recommended as a switch option in virologically suppressed HIV patients. Literature suggests that virological failure with dual therapy could possibly relate to subtherapeutic drug concentrations. In this study, we aimed at describing the DTG and RPV trough plasma concentrations (Cmin) and plasma HIV-1 RNA viral load (VL) during maintenance dual therapy.

METHODS

We performed a retrospective analysis of DTG and RPV therapeutic drug monitoring in people living with HIV/AIDS (PLWHA) with dual therapy in 9 French centres. DTG and RPV trough plasma concentrations were estimated using a Bayesian approach to predict Cmin. The relationship between the pharmacokinetics of DTG and RPV and VL > 50 copies (cp)/mL was explored using joint nonlinear mixed models. The frequency of subtherapeutic threshold (DTG Cmin below 640 ng/mL and RPV Cmin below 50 ng/mL) were compared between PLWHA presenting VL > 50 cp/mL or not during the study.

RESULTS

At baseline, 209 PLWHA were enrolled in the study. At week 48, 19 people living with HIV/AIDS (9.1%) discontinued their treatment and 15 PLWHA (7.1%) exhibited VL > 50 cp/mL. Six PLWHA out of 15 (40.0%) with VL > 50 cp/mL during the follow-up had at least 1 Cmin below the respective thresholds while only 26/194 patients (13.4%) without virological replication had at least 1 concentration below the threshold (P = .015).

CONCLUSION

A majority of PLWHA receiving DTG/RPV maintenance dual therapy demonstrated VL < 50 cp/mL but virological replication was more frequent in people living with HIV/AIDS with subtherapeutic Cmin.

A Comprehensive Literature Review of Treatment-Emergent Integrase Resistance with Dolutegravir-Based Regimens in Real-World Settings

After a decade of dolutegravir (DTG) use in various antiretroviral therapy combinations and in diverse populations globally, it is critical to identify HIV strains with reduced drug susceptibility and monitor emergent resistance in people living with HIV who experience virologic failure while on DTG-based regimens. We searched the PubMed, Embase, and Cochrane databases to identify studies that reported DTG resistance-associated mutations (RAMs) emerging under selection pressure. Our review showed that RAMs conferring resistance to DTG were rare in 2-drug and 3-drug regimens used in real-world cohorts, corroborating data from clinical trials. The potency of DTG in maintaining virologic suppression was demonstrated, even in cases of pre-existing resistance to companion drugs in the regimen. Estimates of DTG RAMs depended on the population and certain risk factors, including monotherapy, baseline resistance or lack of genotypic testing, treatment history and prior virologic failure, and suboptimal treatment adherence. The RAMs detected after virologic failure, often in heavily treatment-experienced individuals with prior exposure to integrase strand transfer inhibitors, were G118R, E138K, G140A/C/R/S, Q148H/K/R, N155H, and R263K. Overall, these data highlight the durable effectiveness and high barrier to resistance of DTG as part of combination antiretroviral therapy in a wide variety of settings.

Efficacy and tolerability of dolutegravir/lamivudine versus dolutegravir/rilpivirine in switching from a three-drug regimen based on nonnucleoside reverse transcriptase inhibitors: A retrospective cohort study

Real-life comparisons of dolutegravir/rilpivirine (DTG/RPV) and DTG/lamivudine (3TC) regimens in people living with human immunodeficiency virus (PLWHIV) who switched from a standard three-drug regimen based on nonnucleoside reverse transcriptase inhibitors (NNRTIs) are missing. This study aimed to compare DTG/3TC and DTG/RPV in virologically suppressed patients (HIV-RNA < 50 copies/mL) coming from any NNRTI-based regimen in terms of discontinuation due to virologic failure (VF) discontinuation rates due to all causes, and adverse events. As a secondary outcome, we evaluated the difference in creatinine, total cholesterol, CD4, and triglycerides from baseline to weeks 48 after the switch. Of the 415 PLWHs included in the study, 278 (66.9%) switched to DTG/3TC, and 137 (33.1%) switched to DTG/RPV. Overall, 48 PLWHs (11.6%) discontinued the treatment:38 with DTG/3TC and 10 with DTG/RPV with similar discontinuation rates: 5.01 × 100 py (95% confidence interval [CI] 3.64-6.94) and 4.66 × 100 py (95% CI 2.51-8.67), respectively. The most common reason for discontinuation was toxicity (26 patients, 22/278 [7.9%] in the DTG/3TC group and 4/137 [2.9%] in the DTG/RPV group), mainly neurologic toxicity (never above grade 2). We found no differences in discontinuation rates due to treatment adverse events. Two study participants experienced virological failure in the DTG/3TC arm. We observed no significant difference in CD4 cell counts, lipid parameters, or renal function between the two groups at 48 weeks. This study demonstrated that, in clinical practice, a two-drug regimen with DTG/3TC or DTG/RPV is characterized by a low discontinuation rate and VF in virologically suppressed PLWHs switched from an NNRTI-based three antiretroviral drugs regimen.

Efficacy and safety of dolutegravir/rilpivirine in real-world clinical practice. GeSIDA study 1119

INTRODUCTION

Dolutegravir/rilpivirine (DTG/RPV) is an effective antiretroviral (ART) regimen endorsed by clinical trials as a switch therapy. The aim of our study was to analyse the efficacy and safety of DTG/RPV in real-world clinical practice.

METHODS

Observational, multicentre study of patients who started DTG/RPV. Efficacy, adverse events and metabolic changes at 48 weeks were analysed.

RESULTS

A total of 348 patients were included; median time of HIV infection was 21.1 years, 33.7% were AIDS cases; median nadir CD4 was 160 cells/μL; 90.5% had received ≥3 lines of ART and 179 (53.8%) had prior virological failure. Convenience (43.5%), toxicity/intolerance (28.4%) and interactions (17.0%) were the main reasons for starting DTG/RPV. Previous regimens were protease inhibitors (PI) (31.6%), non-nucleoside reverse transcriptase inhibitors (NNRTI) (20.4%) and integrase strand transfer inhibitors (INSTI) (14.9%). Efficacy (HIV-RNA <50 copies/mL) at 48 weeks was 89.7% (95% CI 86.1-92.6) by intention-to-treat (ITT) and 94.2% (95% CI 91.3-96.4) by on treatment (OT); 10 patients (3.1%) were not suppressed (3 had abandoned ART). There was a mean decrease in triglycerides, total cholesterol, low-density lipoprotein-cholesterol, glutamic-pyruvic transaminase (GPT), gamma-glutamyl transferase (GGT) and alkaline phosphatase; creatinine increased with a decrease in glomerular filtration rate.

CONCLUSIONS

This study confirms the effectiveness, tolerability and safety of DTG/RPV in real-world clinical practice in a different population from clinical trials, with many years of infection, low CD4 nadir, several previous treatment lines, more than half with virological failures, and one-third diagnosed with AIDS. The switch to DTG/RPV was safe with few discontinuations due to adverse effects. Modifications of the lipid and liver profiles were favourable. There were no relevant changes in kidney function.

Evaluation of integrase resistance in individuals who failed a regimen containing dolutegravir in French and Italian clinical settings

BACKGROUND

This work aims to evaluate integrase resistance and its predictors in HIV-1 infected combined antiretroviral therapy (cART) experienced individuals failing a dolutegravir-based regimen.

METHODS

Major resistance mutations (MRM) and genotypic susceptibility score (GSS) of dolutegravir companion drugs were evaluated on plasma genotypic resistance test (GRT) performed at dolutegravir failure. Logistic regression was used to evaluate factors associated to the risk of integrase strand-transfer inhibitors (INSTI)-resistance at dolutegravir failure.

RESULTS

We retrospectively analysed 467 individuals. At failure GRT, individuals had been under dolutegravir for a median (IQR) time of 11 (5-20) months; around half of them had never been exposed to INSTI (52%) and 10.7% were at first-line regimen. Fifty-eight (12.4%) individuals showed ≥1 INSTI MRM. Among them, people INSTI-exposed showed significantly higher prevalence of INSTI resistance compared to those who were INSTI naïve [46 (21.2%) versus 9 (3.9%), P < 0.001].N155H was the most prevalent MRM (5.4%), followed by G140S (4.5%) and Q148H (4.3%). These MRM were more probably present in INSTI-experienced individuals compared to those INSTI naïve. Despite failure, 89.5% of individuals harboured viral strains fully susceptible to dolutegravir and bictegravir and 85.0% to all INSTI. No INSTI exposure before receiving dolutegravir [OR: 0.35 (0.16-0.78), P < 0.010] and a GSS for companion drugs ≥2 (OR: 0.09 [0.04-0.23], P < 0.001) were negatively associated with INSTI resistance at failure.

CONCLUSIONS

In a large set of individuals failing dolutegravir in real-life, INSTI resistance was low and mainly related to previous first-generation INSTI exposure. Surveillance of integrase resistance remains crucial to preserve efficacy of INSTI class in the future.

Real world efficacy of dolutegravir plus lamivudine in people living with HIV with undetectable viral load after previous failures

BACKGROUND

Dolutegravir (DTG) +lamivudine (3TC) combination has been found to be as effective as triple therapies, and has been extensively prescribed in clinical practice as a maintenance therapy. We aimed to investigate the effect of previous virological failures (VFs) on virological efficacy.

METHODS

The analysis included data of people living with HIV (PLWH) with HIV-RNA ≤50 copies/mL enrolled in an Italian retrospective multicohort study who were switching to DTG+3TC. Primary endpoint was viral rebound (VR; confirmed HIV-RNA ≥50 copies/mL or single HIV-RNA ≥50 copies/mL followed by change of antiretroviral therapies [ART]). Kaplan-Meier curves were used to estimate probabilities of VR based upon histories of previous VFs (single HIV-RNA ≥1000 copies/mL or confirmed HIV-RNA ≥50 copies/mL). A weighted Cox regression model was fitted to estimate the causal hazard ratio (HR) of history of failure on the risk of VR.

RESULTS

A total of 966 PLWH were included; 20.1% had a history of previous VF. VR was detected in 23 PLWH. The one-year probability was 1.2% (95% confidence interval [CI], 0.2%-2.2%) in PLWH without previous VF and 3.3% (95% CI, 0.4%-6.2%) in those with ≥1 VF (log-rank P = 0.042). By multivariate analysis adjusted for CD4+ cell count at nadir, duration of virological suppression, and mode of HIV transmission, PLWH with ≥1 previous VF had a higher risk of virological rebound than those without previous VF (adjusted hazard ratio 3.06 [95% CI, 1.00-9.44], P = 0.051).

CONCLUSION

Despite the low absolute one-year risk in both groups, real-world data confirmed that PLWH with a previous failure have an increased risk of viral rebound.

Genotypic Resistance Testing of HIV-1 DNA in Peripheral Blood Mononuclear Cells

HIV-1 DNA exists in nonintegrated linear and circular episomal forms and as integrated proviruses. In patients with plasma viremia, most peripheral blood mononuclear cell (PBMC) HIV-1 DNA consists of recently produced nonintegrated virus DNA while in patients with prolonged virological suppression (VS) on antiretroviral therapy (ART), most PBMC HIV-1 DNA consists of proviral DNA produced months to years earlier. Drug-resistance mutations (DRMs) in PBMCs are more likely to coexist with ancestral wild-type virus populations than they are in plasma, explaining why next-generation sequencing is particularly useful for the detection of PBMC-associated DRMs. In patients with ongoing high levels of active virus replication, the DRMs detected in PBMCs and in plasma are usually highly concordant. However, in patients with lower levels of virus replication, it may take several months for plasma virus DRMs to reach detectable levels in PBMCs. This time lag explains why, in patients with VS, PBMC genotypic resistance testing (GRT) is less sensitive than historical plasma virus GRT, if previous episodes of virological failure and emergent DRMs were either not prolonged or not associated with high levels of plasma viremia. Despite the increasing use of PBMC GRT in patients with VS, few studies have examined the predictive value of DRMs on the response to a simplified ART regimen. In this review, we summarize what is known about PBMC HIV-1 DNA dynamics, particularly in patients with suppressed plasma viremia, the methods used for PBMC HIV-1 GRT, and the scenarios in which PBMC GRT has been used clinically.