Optimizing Antiretroviral Therapy in Treatment-Experienced Patients Living with HIV: A Critical Review of Switch and Simplification Strategies. An Opinion of the HIV Practice and Research Network of the American College of Clinical Pharmacy

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.

Tenofovir alafenamide plus dolutegravir as a switch strategy in HIV-infected patients: a pilot randomized controlled trial

BACKGROUND

Currently, two-drug antiretroviral regimens are emerging fields in life-long treatment in people living with HIV.

OBJECTIVES

This randomized non-inferiority open-label controlled trial was designed to compare the 48-week efficacy and safety of tenofovir alafenamide plus dolutegravir versus the standard triple therapy in virologically suppressed people living with HIV. To the best of our knowledge this combination has not been studied before.

METHODS

This open-label randomized controlled trial was conducted in treatment-experienced people with HIV who had HIV-RNA < 47 copies/mL for at least two years. Patients received either tenofovir alafenamide plus dolutegravir combination (26 patients) or a standard three-drug regimen (29 patients). The primary outcome was the proportion of patients maintaining HIV-RNA < 47 copies/mL during 48 weeks, and the secondary outcomes were CD4 cell count changes, the adherence rate, and adverse drug reactions, all over 48 weeks of study.

RESULTS

HIV viral load remained undetectable (HIV-RNA < 47 copies/mL) during the 48 weeks of the study in both arms. The absolute CD4 cell count change was not significant between the two groups. The overall proportion of adverse effects in each group was comparable. The rate of adherence to treatment was acceptable in both groups, and no significant difference was observed.

CONCLUSIONS

Treatment simplification with tenofovir alafenamide plus dolutegravir regimen as maintenance therapy was non-inferior in terms of efficacy and safety compared to the standard triple therapy. Comparing efficacy of antiretroviral therapy.

Temporal trend of drug-resistance and APOBEC editing in PBMC genotypic resistance tests from HIV-1 infected virologically suppressed individuals

BACKGROUND

We aimed at evaluating the temporal trend of drug-resistance and APOBEC editing from HIV-DNA genotypic resistance tests (GRT) in virologically suppressed individuals.

MATERIAL AND METHODS

Major resistance mutations (MRM), genotypic susceptibility score (GSS) for the current regimen and APOBEC-related mutations (APO-M) were evaluated. Potential changes in trends of MRM and APO-M over-time were assessed and predictors of MRM detection or sub-optimal GSS (GSS<2) at HIV-DNA-GRT were estimated through logistic regression analyses.

RESULTS

Among the 1126 individuals included, 396 (35.2%) harboured at least one MRM (23.4% to NRTI, 18.8% to NNRTI, 7.7% to PI and 1.4% to INSTI [N=724]); 132 (12.3%) individuals showed a GSS <2. APO-M and stop codons were found in 229 (20.3%) and 105 (9.3%) individuals, respectively. APO-DRMs were found in 16.8% of individuals and were more likely observed in those individuals with stop codons (40.0%) compared to those without (14.4%, P<0.001). From 2010 to 2021 no significant changes of resistance or APO-M were found. Positive predictors of MRM detection at HIV-DNA GRT were drug abuse, subtype B infection, and a prolonged and complex treatment history. Perinatal infection and having at least 2 stop codons were associated with a current suboptimal regimen.

CONCLUSIONS

In virologically suppressed individuals, resistance in HIV-DNA and the extent of APOBEC editing were generally stable in the last decade. A careful evaluation of APOBEC editing might be helpful to improve the reliability of HIV-DNA GRT. Further investigations are required to understand how to apply the estimation of APOBEC editing in refining genotypic evaluation.

The New Era of Long-Acting Antiretroviral Therapy: When and Why to Make the Switch

PURPOSE OF REVIEW

Despite the availability of safe and effective oral combination antiretroviral therapy, barriers to maintaining viral suppression remain a challenge to ending the HIV epidemic. Long-acting injectable antiretroviral therapy was developed as an alternative to daily oral therapy. This review summarizes the current literature on the efficacy of long-acting cabotegravir plus rilpivirine for the treatment of HIV-1, reasons to switch to injectable therapy, and barriers to switching.

RECENT FINDINGS

Long-acting cabotegravir plus rilpivirine is safe and effective in maintaining HIV-1 virologic suppression. Ideal candidates for switching to long-acting cabotegravir plus rilpivirine are virologically suppressed on oral regimens with good adherence and no history of virologic failure or baseline resistance. Indications to switch to injectable therapy include patient preference, the potential for improved adherence, and avoidance of adverse effects. Implementation research is needed to assess and overcome system barriers. Long-acting cabotegravir plus rilpivirine is a novel alternative to oral antiretrovirals, with the potential to improve adherence and quality of life in people with HIV.

Convenience, efficacy, safety, and durability of INSTI-based antiretroviral therapies: evidence from the Italian MaSTER cohort

BACKGROUND

Integrase strand transferase inhibitors (INSTI), including raltegravir (RAL), elvitegravir (ELV), and dolutegravir (DTG), have demonstrated better efficacy and tolerability than other combination antiretroviral therapy (cART) classes in clinical trials; however, studies of sustainability of INSTI-containing therapy in the long-term are sparse. The purpose of this study was to provide an epidemiological overview comparing the outcome performance of different INSTI-based regimens longitudinally, including the metrics of efficacy, safety, convenience, and durability among a large, nationally representative cohort of persons living with HIV in Italy.

METHODS

We selected subjects in the MaSTER cohort (an Italian multicenter, hospital-based cohort established in the mid-1990s that currently has enrolled over 24,000 PLWH) who initiated an INSTI-based regimen either when naïve or following a regimen switch. Cox proportional hazards regression models were fitted to evaluate associations between therapy interruptions and age, sex, nationality, transmission risk group, viral suppression status, CD4 + T-cell count, diagnosis year, cART status (naïve or experienced), and hepatitis coinfection. Results were stratified by cART INSTI type.

RESULTS

There were 8173 participants who initiated an INSTI-based cART regimen in the MaSTER cohort between 2009 and 2017. The population was majority male (72.6%), of Italian nationality (88.6%), and cART-experienced (83.0%). Mean age was 49.7 (standard deviation: 13.9) years. In total, interruptions of the 1st INSTI-based treatment were recorded in 34% of cases. The most frequently cited reason for interruption among all three drug types was safety problems. In the survival analysis, past history of cART use was associated with higher hazards of interruption due to poor efficacy for all three drug types when compared to persons who were cART naïve. Non-viral suppression and CD4 + T-cell count < 200/mm3 at baseline were associated with higher hazards of interruption due to efficacy, safety, and durability reasons. Non-Italian nationality was linked to higher hazards of efficacy interruption for RAL and EVG. Age was negatively associated with interruption due to convenience and positively associated with interruption due to safety reasons. People who injects drugs (PWID) were associated with higher hazards of interruption due to convenience problems. Hepatitis coinfection was linked to higher hazards of interruption due to safety concerns for people receiving RAL.

CONCLUSION

One-third of the population experienced an interruption of any drugs included in INSTI therapy in this study. The most frequent reason for interruption was safety concerns which accounted for one-fifth of interruptions among the full study population, mainly switched to DTG. The hazard for interruption was higher for low baseline CD4 + T-cell counts, higher baseline HIV-RNA, non-Italian nationality, older age, PWID and possible co-infections with hepatitis viruses. The risk ratio was higher for past history of cART use compared to persons who were cART naive, use of regimens containing 3 drugs compared to regimens containing 2 drugs. Durability worked in favor of DTG which appeared to perform better in this cohort compared to RAL and EVG, though length of follow-up was significantly shorter for DTG. These observational results need to be confirmed in further perspective studies with longer follow-up.

Efficacy and safety of switching to dolutegravir plus lamivudine versus continuing triple antiretroviral therapy in virologically suppressed adults with HIV at 48 weeks (DOLAM): a randomised non-inferiority trial

BACKGROUND

Simplified antiretroviral therapy (ART) regimens are desirable for people with HIV. We investigated the efficacy and safety of switching from triple ART to dual dolutegravir plus lamivudine therapy.

METHODS

DOLAM is a phase 4, randomised, open-label, non-inferiority trial, done at six HIV clinics in Catalonia, Spain. Adults with HIV-1 receiving a triple ART regimen, aged 18 years or older, with virological suppression, a CD4 nadir of at least 200 cells per μL, who were HBsAg-negative, and without previous viral failure or resistance mutations to study drugs were eligible. Participants underwent computer-generated randomisation, stratified by the class of the third drug, and were assigned (1:1) to switch to oral dolutegravir 50 mg and lamivudine 300 mg once daily or to continue triple ART for 48 weeks. The primary endpoint was the proportion of people with an HIV RNA value of at least 50 copies per mL at week 48 (US Food and Drug Administration snapshot algorithm, 8% non-inferiority margin). Both the primary and safety outcomes were evaluated in the intention-to-treat exposed population. The study is completed and was registered with EudraCT 201500027435.

FINDINGS

Between July 7, 2015, and Oct 31, 2018, 265 participants were randomly assigned to switch to dolutegravir plus lamivudine (n=131) or to maintain triple ART (n=134) and all received at least one dose. Nine (7%) participants in the dual therapy group and ten (7%) in the triple therapy group were excluded before 48 weeks, mostly due to treatment discontinuations or virological failure. Participants were predominantly male (116 [87%] of 134 in the triple ART group and 111 [85%] of 131 in the dolutegravir plus lamivudine group). The difference in the proportion of participants with HIV RNA values of at least 50 copies per mL at 48 weeks between the dual therapy group (three [2%] of 131) and triple therapy group (two [1%] of 134) was 0·8 percentage points (95% CI -3·3 to 5·2), showing non-inferiority of dolutegravir plus lamivudine dual therapy compared with triple ART. 73 (56%) of 131 participants allocated to dual therapy had 150 adverse effects, compared with 78 (58%) of 134 participants allocated to triple therapy who also had 150 adverse events (p=0·68). Drug discontinuation due to adverse effects occurred in four people in the triple therapy group and three people in the dual therapy group.

INTERPRETATION

Our findings show the efficacy and safety of dolutegravir plus lamivudine as a simplified therapy switch option for selected people with HIV with virological suppression on triple ART.

FUNDING

Instituto de Salud Carlos III, Red de Investigación en Sida, and ViiV Healthcare.

Incidence and Severity of Drug Interactions Before and After Switching Antiretroviral Therapy to Bictegravir/Emtricitabine/Tenofovir Alafenamide in Treatment-Experienced Patients

Background

Switching antiretroviral therapy (ART) in people with HIV (PWH) can influence their risk for drug–drug interactions (DDIs). The purpose of this study was to assess changes in the incidence and severity of DDIs among PWH who switched their ART to bictegravir/emtricitabine/tenofovir alafenamide (BIC/FTC/TAF).

Methods

This was a multicenter retrospective cohort study of PWH on ART and at least 1 concomitant medication (CM) who switched to BIC/FTC/TAF between 3/2018 and 6/2019. Using the University of Liverpool’s HIV Drug Interaction Database, 2 DDI analyses were performed for each patient. The first assessed patients’ preswitch ART regimens with their CM list. The second assessed the same CM list with BIC/FTC/TAF. Each ART-CM combination was given a score of 0 (no or potential weak interaction), 1 (potential interaction), or 2 (contraindicated interaction). A paired t test analyzed changes in total DDI scores following ART switches, and linear regression examined factors contributing to DDI score reductions.

Results

Among 411 patients, 236 (57%) had at least 1 DDI present at baseline. On average, baseline DDI scores (SD) were 1.4 (1.8) and decreased by 1 point (95% CI, –1.1 to –0.8) after patients switched to BIC/FTC/TAF (P < .0001). After adjusting for demographics, baseline ART, and CM categories, switching to BIC/FTC/TAF led to significant DDI score reductions in patients receiving CMs for cardiovascular disease, neurologic/psychiatric disorders, chronic pain, inflammation, gastrointestinal/urologic conditions, and conditions requiring hormonal therapy.

Conclusions

Treatment-experienced PWH eligible to switch their ART may experience significant declines in number and severity of DDIs if switched to BIC/FTC/TAF.