Virological outcomes with dolutegravir plus either lamivudine or two NRTIs as switch strategies: a multi-cohort study

Durability of doravirine with dolutegravir dual regimen compared with other dolutegravir-based dual combinations

OBJECTIVES

The availability of doravirine (DOR) allowed clinicians to prescribe a dolutegravir (DTG)-based two-drug regimen (2DR) in individuals not eligible to receive lamivudine (3TC) or rilpivirine (RPV). The aims of this study were to describe the durability of DTG + DOR compared with DTG/3TC and DTG/RPV and the rate of virological failure and target not-detected maintenance over time.

METHODS

This retrospective, monocentric analysis included all subjects who started a DTG-based 2DR from 2018 to 2022 as a simplification. Descriptive statistics and non-parametric tests to describe and compare the groups were applied. Kaplan-Meier probability curves and Cox regression models for regimens durability were used.

RESULTS

The study enrolled 710 individuals: 499 treated with DTG/3TC, 140 with DTG/RPV, and 71 with DTG + DOR. A 2DR with DOR was prescribed to older subjects who had a longer infection, greater exposure to different antiretroviral regimens, a higher proportion of resistance-associated mutations, and a worse immune-virologic status. Over a cumulative follow-up of 68 152 weeks, 42 discontinuations were registered (5.9%). DTG + DOR had a risk of treatment interruption of 7.8% at 48 weeks and 9.8% at 96 weeks, significantly higher than the other 2DRs. In the multivariate Cox model, DTG + DOR and DTG/RPV were significantly associated with discontinuation. The maintenance of target not detected during follow-up was similar among groups. The rate of virological failure was higher for DTG + DOR through different event definitions.

CONCLUSIONS

DTG + DOR durability was high over a long follow-up albeit lower than for other 2DRs. This combination might be an effective option in people with HIV that has proven difficult to treat.

Efficacy of Lamivudine Plus Dolutegravir vs Dolutegravir-Based 3-Drug Regimens in People With HIV Who Are Virologically Suppressed

Background

Lamivudine + dolutegravir maintenance dual therapy (DT) could be less effective than 3-drug therapy (TT) in the context of resistance-associated mutations to nucleoside reverse transcriptase inhibitors (NRTIs). The ARCA database was queried to test this hypothesis with a trial emulation strategy.

Methods

People with HIV taking 2 NRTIs plus a protease inhibitor or a non-NRTI who switched to DT or dolutegravir-based TT were followed up from the first HIV RNA <50 copies/mL (baseline) to virologic failure (VF; ie, 2 consecutive HIV RNA ≥50 copies/mL or 1 HIV RNA ≥200 copies/mL). Those switching to DT within 6 months were assigned to the treatment arm and all other patients to the control arm. Each participant was also cloned, assigned to the opposite strategy, and censored at the time of deviation from that strategy. Using inverse probability of censoring weight Cox regression models, we calculated hazard ratios of VF for DT vs TT stratified for the presence of resistance-associated mutations.

Results

Overall 626 people were analyzed: 204 with DT and 422 with TT (73% men; mean age, 44 years). Ten and 31 VFs occurred with DT and TT, respectively, over a median 5.8 years. When compared with a fully active TT, the DT had similar efficacy (adjusted hazard ratio, 0.88; 95% CI, .29-2.61; P = .812) when full susceptibility was confirmed at historical genotype. When previous M184V/I was present in both groups, the risk of VF was higher for DT vs TT but was not statistically significant (adjusted hazard ratio, 3.06; 95% CI, .45-20.84; P = .252).

Conclusions

DT was not associated with a significantly higher risk of VF than dolutegravir-based TT.

Switching to Dolutegravir/Lamivudine Two-Drug Regimen: Durability and Virologic Outcomes by Age, Sex, and Race in Routine US Clinical Care

Purpose

Two-drug regimens (2DR) may address drug-drug interactions and toxicity concerns. Dolutegravir/lamivudine (DTG/3TC) 2DR was approved in the US for both treatment-naïve and treatment-experienced individuals with a viral load <50 copies/mL. This study describes real-world DTG/3TC 2DR treatment outcomes among treatment-experienced individuals, stratified by age, sex, and race.

Methods

From the OPERA® cohort, people with HIV with a viral load <50 copies/mL who switched from a commonly used three-drug regimen to DTG/3TC 2DR as per the label between April 8, 2019 and April 30, 2021 were included. Incidence rates (Poisson regression) for loss of virologic control (first viral load ≥50 copies/mL), confirmed virologic failure (2 viral loads ≥200 copies/mL or discontinuation after 1 viral load ≥200 copies/mL), and DTG/3TC 2DR discontinuation were estimated overall and stratified by age, sex, and race.

Results

The 787 individuals included were followed for a median of 13.6 months (IQR: 8.2, 22.3). Confirmed virologic failure occurred in ≤5 individuals. Loss of virologic control occurred at a rate of 14.0 per 100 person-years (95% CI: 11.7, 16.8). DTG/3TC 2DR discontinuation occurred at a rate of 17.5 per 100 person-years (95% CI: 15.0, 20.3); 4% discontinued for treatment-related reasons (viremia, adverse diagnosis, side effect, lab abnormality). For all outcomes, incidence rates were comparable across strata of age, sex, and race.

Conclusion

This descriptive study demonstrates that DTG/3TC 2DR is an effective and well-tolerated treatment option for people with HIV with a viral load <50 copies/mL at switch, regardless of their age, sex, or race.

Effectiveness, Weight Changes, and Metabolic Outcomes on Switch to Generic Dolutegravir/Lamivudine Among People with HIV in Western India: An Observational Study

We assessed the effectiveness and safety of switching to generic dolutegravir/lamivudine (DTG/3TC) among People living with Human Immunodeficiency Virus (PWH) in Western India. In this single-center, retrospective observational study, PWH, who switched to DTG/3TC, were followed for virologic, immunologic, and clinical effectiveness, and safety, including weight changes, hyperglycemia, and dyslipidemia. Multivariate linear mixed-effects models were used to predict average change in weight adjusted for age, sex, duration of previous antiretroviral (ARV) regimens, and baseline weight. From May 2017 to July 2022, out of 434 PWH switched to DTG/3TC, 304 with at least 1 follow-up visit were included. Median [interquartile range (IQR)] age was 54 (IQR 49-61) years and 70.1% were male. Prevalence of baseline comorbidities was 57.9% (hypertension-41.5%, chronic kidney disease-40.9%, and diabetes mellitus-18.8%). Reasons for switch were affordability (47.4%), desire for simplification (41.8%), ARV toxicities (19.1%), and concern about potential toxicities (10.2%). Median (IQR) duration of follow-up on DTG/3TC was 40 (IQR 31-49) weeks. No virologic failure was observed. Rates of virologic suppression [viral load (VL) ≤20 copies/mL or target not detected (TND)] at 12, 24, 48, 72, 96 and 120 weeks were 95.2%, 95.9%, 90%, 100%, 81.3%, and 88.4%, respectively. Only 9 (3%) PWH permanently discontinued DTG/3TC. Predicted adjusted mean weight gain of +3.3 kg was observed at 96 weeks. Switching from tenofovir disoproxil fumarate (TDF)/emtricitabine or lamivudine (XTC)/non-nucleoside reverse transcriptase inhibitor (NNRTI) and duration on DTG/3TC were significantly associated with weight gain. Apart from trend in worsening hyperglycemia (nine PWH with new onset diabetes), no clinically significant change in lipids and estimated glomerular filtration rate (eGFR) was documented. Switching to DTG/3TC is an effective and safe option among virologically suppressed PWH with high comorbidity burden in India. In view of the several advantages of DTG/3TC, it may be considered for potential scale-up in the right population, both in private and public health care settings in India.

Prevalence of Emergent Dolutegravir Resistance Mutations in People Living with HIV: A Rapid Scoping Review

BACKGROUND

Dolutegravir (DTG) is a cornerstone of global antiretroviral (ARV) therapy (ART) due to its high efficacy and favorable tolerability. However, limited data exist regarding the risk of emergent integrase strand transfer inhibitor (INSTI) drug-resistance mutations (DRMs) in individuals receiving DTG-containing ART.

METHODS

We performed a PubMed search using the term "Dolutegravir", last updated 18 December 2023, to estimate the prevalence of VF with emergent INSTI DRMs in people living with HIV (PLWH) without previous VF on an INSTI who received DTG-containing ART.

RESULTS

Of 2131 retrieved records, 43 clinical trials, 39 cohorts, and 6 cross-sectional studies provided data across 6 clinical scenarios based on ART history, virological status, and co-administered ARVs: (1) ART-naïve PLWH receiving DTG plus two NRTIs; (2) ART-naïve PLWH receiving DTG plus lamivudine; (3) ART-experienced PLWH with VF on a previous regimen receiving DTG plus two NRTIs; (4) ART-experienced PLWH with virological suppression receiving DTG plus two NRTIs; (5) ART-experienced PLWH with virological suppression receiving DTG and a second ARV; and (6) ART-experienced PLWH with virological suppression receiving DTG monotherapy. The median proportion of PLWH in clinical trials with emergent INSTI DRMs was 1.5% for scenario 3 and 3.4% for scenario 6. In the remaining four trial scenarios, VF prevalence with emergent INSTI DRMs was ≤0.1%. Data from cohort studies minimally influenced prevalence estimates from clinical trials, whereas cross-sectional studies yielded prevalence data lacking denominator details.

CONCLUSIONS

In clinical trials, the prevalence of VF with emergent INSTI DRMs in PLWH receiving DTG-containing regimens has been low. Novel approaches are required to assess VF prevalence with emergent INSTI DRMs in PLWH receiving DTG in real-world settings.

Impact of preexisting nucleos(t)ide reverse transcriptase inhibitor resistance on the effectiveness of bictegravir/emtricitabine/tenofovir alafenamide in treatment experience patients

INTRODUCTION

Few clinical trials and cohort studies have evaluated the efficacy of bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) in people with HIV (PWH) with preexisting M184V/I or other nucleos(t)ide reverse transcriptase inhibitor (NRTI) resistance-associated mutations (RAMs). Real-world data are also scarce.

METHODS

Retrospective review of treatment-experienced patients who started B/F/TAF in a cohort of PWH. HIV-RNA less than 50 copies/ml was analyzed at 48 weeks in an intention-to-treat (ITT) analysis (missing=failure) and per protocol analysis (patients with missing data or changes for reasons other than virological failure were excluded). Results were compared in patients with and without previous NRTI-RAMs.

RESULTS

Five hundred and six PWH were included (16.2% women). Median age and time with HIV infection were 52.3 and 18.9 years, respectively. At baseline, viral load was less than 50 copies/ml in 440 patients (86.6%). Overall, 69 (13.6%) participants had documented preexisting NRTI-RAMs: 57 (11.2%) M184V/I and 30 (5.9%) tenofovir RAMs. In the ITT analysis, 83% (420/506) had HIV-RNA less than 50 copies/ml [82.2% (359/437) and 88.4% (61/69) in persons without and with NRTI-RAMs, respectively ( P  = 0.2)]. In the per protocol analysis 94.2% (420/445) had HIV-RNA less than 50 copies/ml [94.4% (359/380) vs. 93.8% (61/65); P  = 0.2]. A total of 61 participants were excluded from the per protocol analysis (23 missing data, 19 discontinued B/F/TAF because of toxicity, 13 for other reasons, and 6 died).

CONCLUSION

Switching to B/F/TAF is well tolerated and effective in the real-world setting, even in patients with preexisting NRTI RAMs, such as M184V and RAMs conferring resistance to tenofovir. These results confirm the robustness of this combination.

How could HIV-1 drug resistance impact preexposure prophylaxis for HIV prevention?

PURPOSE OF REVIEW

To review current laboratory and clinical data on the frequency and relative risk of drug resistance and range of mutations selected from approved and investigational antiretroviral agents used for preexposure prophylaxis (PrEP) of HIV-1 infection, including tenofovir disproxil fumarate (TDF)-based oral PrEP, dapivirine ring, injectable cabotegravir (CAB), islatravir, lenacapavir and broadly neutralizing antibodies (bNAbs).

RECENT FINDINGS

The greatest risk of HIV-1 resistance from PrEP with oral TDF/emtricitabine (FTC) or injectable CAB is from starting or continuing PrEP after undiagnosed acute HIV infection. By contrast, the dapivirine intravaginal ring does not appear to select nonnucleoside reverse transcriptase inhibitor resistance in clinical trial settings. Investigational inhibitors including islatravir, lenacapavir, and bNAbs are promising for use as PrEP due to their potential for sustained delivery and low risk of cross-resistance to currently used antiretrovirals, but surveillance for emergence of resistance mutations in more HIV-1 gene regions (gag, env) will be important as the same drugs are being developed for HIV therapy.

SUMMARY

PrEP is highly effective in preventing HIV infection. Although HIV drug resistance from PrEP use could impact future options in individuals who seroconvert on PrEP, the current risk is low and continued monitoring for the emergence of resistance and cross-resistance during product development, clinical studies, and product roll-out is advised to preserve antiretroviral efficacy for both treatment and prevention.