M184V/I does not impact the efficacy of abacavir/lamivudine/dolutegravir use as switch therapy in virologically suppressed patients

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.

Virologic Response to Dolutegravir Plus Lamivudine in People With Suppressed Human Immunodeficiency Virus Type 1 and Historical M184V/I: A Systematic Literature Review and Meta-analysis

Background

To investigate the impact of the M184V/I mutation on virologic response to dolutegravir plus lamivudine (DTG + 3TC) in suppressed-switch populations, a meta-analysis was performed using virologic outcomes from people with human immunodeficiency virus type 1 (PWH) with and without M184V/I before DTG + 3TC switch in real-world studies identified via systematic literature review. Sensitivity analyses were performed using data from PWH with M184V/I in interventional studies identified via targeted literature review.

Methods

Single-arm meta-analyses using common- and random-effects models were used to estimate proportions of PWH with virologic failure (VF) among real-world populations with and without M184V/I and interventional study participants with M184V/I at 24, 48, and 96 weeks.

Results

Literature reviews identified 5 real-world studies from 3907 publications and 51 abstracts meeting inclusion criteria and 5 interventional studies from 1789 publications and 3 abstracts. All time points had low VF incidence in PWH with M184V/I (real-world: 1.43%-3.81%; interventional: 0.00%) and without (real-world: 0.73%-2.37%). Meta-analysis-estimated proportions (95% confidence interval) with VF were low at weeks 24, 48, and 96, respectively, for PWH with M184V/I (real-world: 0.01 [.00-.04], 0.03 [.01-.06], and 0.04 [.01-.07]; interventional: 0.00 [.00-.02], 0.00 [.00-.01], and 0.00 [.00-.03]) and without (real-world: 0.00 [.00-.02], 0.02 [.01-.04], and 0.02 [.00-.05]). One real-world study (n = 712) reported treatment-emergent M184V at VF in 1 of 652 (0.15%) PWH without prior M184V/I.

Conclusions

Results suggest that prior M184V/I has minimal impact on virologic suppression after switching to DTG + 3TC and provide reassurance when considering switching regimens in virologically suppressed PWH with incomplete treatment history or limited treatment options.

Limited emergence of resistance to integrase strand transfer inhibitors (INSTIs) in ART-experienced participants failing dolutegravir-based antiretroviral therapy: a cross-sectional analysis of a Northeast Nigerian cohort

BACKGROUND

Due to the high prevalence of resistance to NNRTI-based ART since 2018, consolidated recommendations from the WHO have indicated dolutegravir as the preferred drug of choice for HIV treatment globally. There is a paucity of resistance outcome data from HIV-1 non-B subtypes circulating across West Africa.

AIMS

We characterized the mutational profiles of persons living with HIV from a cross-sectional cohort in North-East Nigeria failing a dolutegravir-based ART regimen.

METHODS

WGS of plasma samples collected from 61 HIV-1-infected participants following virological failure of dolutegravir-based ART were sequenced using the Illumina platform. Sequencing was successfully completed for samples from 55 participants. Following quality control, 33 full genomes were analysed from participants with a median age of 40 years and median time on ART of 9 years. HIV-1 subtyping was performed using SNAPPy.

RESULTS

Most participants had mutational profiles reflective of exposure to previous first- and second-line ART regimens comprised NRTIs and NNRTIs. More than half of participants had one or more drug resistance-associated mutations (DRMs) affecting susceptibility to NRTIs (17/33; 52%) and NNRTIs (24/33; 73%). Almost a quarter of participants (8/33; 24.4%) had one or more DRMs affecting tenofovir susceptibility. Only one participant, infected with HIV-1 subtype G, had evidence of DRMs affecting dolutegravir susceptibility-this was characterized by the T66A, G118R, E138K and R263K mutations.

CONCLUSIONS

This study found a low prevalence of resistance to dolutegravir; the data are therefore supportive of the continual rollout of dolutegravir as the primary first-line regimen for ART-naive participants and the preferred switch to second-line ART across the region. However, population-level, longer-term data collection on dolutegravir outcomes are required to further guide implementation and policy action across the region.

Bictegravir/emtricitabine/tenofovir alafenamide in patients with genotypic NRTI resistance

BACKGROUND

Bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) is approved for treatment of HIV without known resistance to its components. Several studies have demonstrated efficacy of B/F/TAF in patients with nucleoside reverse transcriptase inhibitor (NRTI) resistance-associated mutations (RAMs), mainly identified by proviral DNA testing, but data on the efficacy of B/F/TAF in patients with NRTI RAMs identified in viraemic plasma are limited.

METHODS

We used a retrospective analysis of patients receiving B/F/TAF identified by searching electronic health records with eligibility confirmed by review of individual patient records. Patients included were ≥ 18 years, had 2019 International Antiviral Socitey-USA (IAS-USA) major RAMs affecting NRTIs detected in viraemic plasma prior to starting B/F/TAF and one or more HIV viral load (VL) after starting B/F/TAF.

RESULTS

In all, 50 patients met the study criteria: mean age of 54 years, mean proximal CD4 count of 609 cells/μL, 64% male. A total of 46 were virologically suppressed (< 200 copies/mL) when B/F/TAF was initiated, two were treatment-naïve, one stopped prior antiretroviral therapy (ART) and one had a VL of 961 HIV-1 RNA copies/mL on ART. Twenty-nine had one NRTI RAM (24 were M184V/I), nine had two NRTI RAMs, three had three NRTI RAMs, four had four NRTI RAMs, two had five NRTI RAMs, one had six NRTI RAMs, one had seven RAMs and one had eight NRTI RAMs. At the last VL on B/F/TAF, a mean of 18.6 months after starting B/F/TAF, 49 out of 50 had VL < 100 copies/mL and one had a VL of 208 copies/mL at 11 months but only filled 5 months of B/F/TAF.

CONCLUSIONS

B/F/TAF was effective in maintaining HIV VL suppression in patients with previously documented NRTI RAMs without integrase resistance.

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.

High efficacy of switching to bictegravir/emtricitabine/tenofovir alafenamide in people with suppressed HIV and preexisting M184V/I

OBJECTIVE

We investigated the prevalence of preexisting M184V/I and associated risk factors among clinical trial participants with suppressed HIV and evaluated the impact of M184V/I on virologic response after switching to bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF).

DESIGN

Participant data were pooled from six clinical trials investigating the safety and efficacy of switching to B/F/TAF in virologically suppressed people with HIV.

METHODS

Preexisting drug resistance was assessed by historical genotypes and/or baseline proviral DNA genotyping. Virologic outcomes were determined by last available on-treatment HIV-1 RNA. Stepwise selection identified potential risk factors for M184V/I in a multivariate logistic regression model.

RESULTS

Altogether, 2034 participants switched treatment regimens to B/F/TAF and had follow-up HIV-1 RNA data, and 1825 of these participants had baseline genotypic data available. Preexisting M184V/I was identified in 182 (10%), mostly by baseline proviral DNA genotype ( n  = 167). Most substitutions were M184V ( n  = 161) or M184V/I mixtures ( n  = 10). Other resistance substitutions were often detected in addition to M184V/I ( n  = 147). At last on-treatment visit, 98% (179/182) with preexisting M184V/I and 99% (2012/2034) of all B/F/TAF-treated participants had HIV-1 RNA less than 50 copies/ml, with no treatment-emergent resistance to B/F/TAF. Among adult participants, factors associated with preexisting M184V/I included other resistance, black race, Hispanic/Latinx ethnicity, lower baseline CD4 + cell count, advanced HIV disease, longer duration of antiretroviral therapy, and greater number of prior third agents.

CONCLUSION

M184V/I was detected in 10% of virologically suppressed clinical trial participants at study baseline. Switching to B/F/TAF demonstrated durable efficacy in maintaining viral suppression, including in those with preexisting M184V/I.

Impact of pre-existent drug resistance on virological efficacy of single tablet regimens in people living with HIV

Despite the broad use of single tablet regimens (STRs), few real-life data are available regarding the impact of pre-existent drug resistance on virological failure (VF). Through this study we aimed to fill this gap, by analyzing a large cohort of individuals selected from the ARCA database. The impact on VF of pre-existent resistance associated mutations (RAMs) and cumulative genotypic susceptibility score (cGSS) before STR start was evaluated through survival analysis. Potential emergence of resistance at VF was also evaluated. Overall, 3916 individuals were included: 678 treatment-naïve (G1), 2309 treatment-experienced aviremic (G2), and 929 viremic (G3); 65.2% of them was treated with an STR based on efavirenz (35.2%) or rilpivirine (30%). At two years after starting STR, the overall probability of VF was 5.9% in G1, 8.7% in G2, and 20.8% in G3. No impact of pre-existent resistance on VF was found in G1. The probability of VF was higher in patients with cGSS<3 (reduced susceptibility to at least one drug) than in those with cGSS=3 (full susceptibility to STR drugs) in both G2 and G3. A higher probability of VF was also found in presence of pre-existent M184V (alone or in combination with pre-existent thymidine analogue mutations). Among patients who failed STR, a significant emergence of RAMs was found only in those exposed to EFV/FTC/TDF in G3 (specifically K103N and M184V). Our results confirm a high efficacy of STRs in clinical settings. Pre-existent resistance seems to influence virological efficacy of STR in treatment-experienced individuals (both aviremic and viremic).

Low-level viremia and virologic failure among people living with HIV who received maintenance therapy with co-formulated bictegravir, emtricitabine and tenofovir alafenamide versus dolutegravir-based regimens

BACKGROUND

Real-world experience with low-level viremia (LLV) and its impact remain less reported among people living with HIV (PLWH) who receive antiretroviral therapy (ART) containing second-generation integrase strand transferase inhibitors (INSTIs), including dolutegravir and bictegravir.

METHODS

Virally suppressed PLWH who had achieved plasma HIV RNA load (PVL) <50 copies/mL for ≥6 months and were switched to either dolutegravir- or bictegravir-based ART were included in this retrospective cohort study. The incidence rates of developing LLV events (PVL, 50-199 copies/mL) and virologic failure (VF) (PVL ≥1000 copies/mL) were compared between the dolutegravir and bictegravir cohorts.

RESULTS

A total of 623 and 862 PLWH switched to dolutegravir-based and bictegravir-based ART, respectively, were included. The incidence rates of developing LLV were 6.2 per 100 person-years of follow-up (PYFU) in the bictegravir cohort and 3.8 per 100 PYFU in the dolutegravir cohort (incidence rate ratio [IRR], 1.63; 95% confidence interval [CI], 0.90-2.95, p=0.08), while the rates of VF were 0.69 per 100 PYFU and 0.95 per 100 PYFU, respectively, in the bictegravir and dolutegravir cohort (IRR, 0.72; 95% CI, 0.12-3.39, p=0.34). Presence of LLV events was not associated with subsequent VF in multivariate analysis. Secondary analysis also demonstrated that resistance-associated mutations (RAMs) to nucleoside reverse-transcriptase inhibitors before switch were not associated with adverse virologic outcomes in either cohort.

CONCLUSIONS

Among virally suppressed PLWH, the incidences of developing LLV or VF were similar after switch to dolutegravir- or bictegravir-based ART. Preexisting RAMs to nucleoside reverse-transcriptase inhibitors or the LLV events were not associated with subsequent VF.

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

OBJECTIVES

To compare the efficacy of dolutegravir plus lamivudine dual therapy (DT) with that of dolutegravir plus two NRTIs triple therapy (TT) as switch strategies.

METHODS

A multicentre cohort of HIV-positive, HBsAg-negative patients with viral suppression (HIV-RNA ≤50 copies/mL) switching to DT or TT was retrospectively selected from the ARCA database. The effect of DT versus TT on virological failure (VF; defined as two consecutive HIV-RNA values >50 copies/mL or one HIV-RNA value ≥200 copies/mL) was evaluated by multivariable Cox regression models, overall and after stratifying for the presence of NRTI resistance-associated mutations (RAMs).

RESULTS

From December 2014 to June 2020, 628 patients were eligible: 118 (18.8%) started tenofovir/emtricitabine/dolutegravir, 306 (48.7%) abacavir/lamivudine/dolutegravir and 204 (32.5%) lamivudine/dolutegravir. The DT group had significantly higher nadir and baseline CD4 counts, a higher duration of viral suppression and a lower prevalence of RAMs at historical genotype. Overall, 41 VF occurred after a median of 1.7 years of follow-up, with a lower, but not statistically significant, rate for DT [versus TT, adjusted HR (aHR) = 0.58, 95% CI = 0.25-1.34]. However, DT was associated with less VF in the absence of RAMs when compared with tenofovir-based TT (aHR = 0.20, 95% CI = 0.06-0.67), but not with abacavir-based TT (aHR = 0.43, 95% CI = 0.17-1.11). Conversely, in the setting of pre-existing M184V/I, DT showed a trend to increased risk of VF (versus tenofovir-based TT, aHR = 137.50, 95% CI = 4.24-4464.06; versus abacavir-based TT, aHR = 33.88, 95% CI = 1.75-656.47).

CONCLUSIONS

Lamivudine/dolutegravir maintenance DT showed similar efficacy to dolutegravir-based TT; however, past M184V/I may favour VF.

A Combination of Amino Acid Mutations Leads to Resistance to Multiple Nucleoside Analogs in Reverse Transcriptases from HIV-1 Subtypes B and C

Resistance to anti-Human Immunodeficiency Virus (HIV) drugs has been a problem from the beginning of antiviral drug treatments. The recent expansion of combination antiretroviral therapy worldwide has led to an increase in resistance to antiretrovirals; understanding the mechanisms of resistance is increasingly important. In this study, we analyzed reverse transcriptase (RT) variants based on sequences derived from an individual who had a low-level rebound viremia while undergoing therapy with abacavir, azidothymidine (AZT or Zidovudine), and (-)-L-2',3'-dideoxy-3'-thiacytidine (Lamivudine or 3TC). The RT had mutations at positions 64, 67, 70, 184, 219, and a threonine insertion after amino acid 69 in RT. The virus remained partially susceptible to the nucleoside reverse transcriptase inhibitor (NRTI) regimen. We show how these mutations affect the ability of NRTIs to inhibit DNA synthesis by RT. The presence of the inserted threonine reduced the susceptibility of the RT mutant to inhibition by Tenofovir.

Impact of archived M184V/I mutation on the effectiveness of switch to co-formulated elvitegravir, cobicistat, emtricitabine and tenofovir alafenamide among virally suppressed people living with HIV

OBJECTIVES

Real-world experience regarding the effectiveness of co-formulated elvitegravir, cobicistat, emtricitabine and tenofovir alafenamide (EVG/C/FTC/TAF) as a switch regimen is sparse among people living with HIV (PLWH) harbouring the M184V/I mutation with or without thymidine analogue-associated mutations (TAMs).

METHODS

In this retrospective multicentre study, PLWH who were switched to EVG/C/FTC/TAF after having achieved viral suppression (plasma HIV RNA <200 copies/mL) for 6 months or longer were included. Patients with archived M184V/I mutation (case patients) were matched to controls without M184V/I mutation at a 1:4 ratio. Patients with a history of virological failure or resistance to elvitegravir were excluded. The primary endpoint was virological non-success (plasma HIV RNA ≥50 copies/mL) at Week 48 of switch using a modified FDA snapshot analysis.

RESULTS

Overall, 100 case patients with the M184V/I mutation were identified, including 6 (6.0%) with K65R and 13 (13.0%) with at least one TAM, and were matched to 400 controls in terms of gender, age (mean = 40.3 versus 39.7 years) and cumulative exposure duration to tenofovir disoproxil fumarate (median = 146 versus 143 weeks). At Week 48, the rate of virological non-success for the case patients and controls was 5.0% (5/100) and 3.3% (13/400), respectively (difference = 1.7%; 95% CI = -2.9%-6.3%), while the rate of virological success was 88.0% and 89.5% for the case patients and controls, respectively. The presence of the K65R mutation or TAMs was not associated with virological non-response.

CONCLUSIONS

Among virally suppressed PLWH, EVG/C/FTC/TAF is effective in maintaining viral suppression at Week 48 despite archived M184V/I mutation with or without TAMs.

Dolutegravir response in antiretroviral therapy naïve and experienced patients with M184V/I: Impact in low-and middle-income settings

BACKGROUND

Dolutegravir (DTG) is now recommended to all HIV infected adults, adolescents, and children of right age by WHO. The low cost of $75 per year for generic DTG-based combination, has allowed 3.9 million people living with HIV (PLWH) in low and middle-income countries (LMICs) access to DTG. Lamivudine and emtricitabine associated M184V/I mutation is highly prevalent in PLWH and the majority of HIV infected individuals receiving DTG regimens may already be carrying M184V/I mutation.

DISCUSSION

Despite high prevalence of M184V/I in antiretroviral therapy (ART) experienced patients, DTG treatment outcomes will likely not be adversely affected by this mutation. The use of DTG in ART naïve has been largely characterised by rare emergence of resistance and virological failure. DTG-based regimens have to great extent been effective at maintaining viral suppression in treatment experienced PLWH carrying M184V/I.

CONCLUSIONS

Initiating patients on DTG may help preserve more treatment options for HIV infected individuals living in LMICs. High genetic barrier to the development of resistance associated with DTG and progressive viral suppression in patients switched to DTG-based therapy with M184V/I, may encourage better DTG outcomes and help in curbing increasing levels of HIV drug resistance in LMICs.

Incidence and impact of low-level viremia among people living with HIV who received protease inhibitor- or dolutegravir-based antiretroviral therapy

OBJECTIVES

The impact of very low-level viremia (VLLV) and low-level viremia (LLV) are rarely investigated among people living with HIV (PLWH) receiving dolutegravir- vs protease inhibitor (PI)-based antiretroviral therapy (ART).

METHODS

Virally suppressed PLWH receiving long-term PI-containing ART were included in this study. The incidences of developing VLLV (plasma HIV RNA load (PVL) 20-49 copies/ml), LLV (PVL 50-999 copies/ml), and virological failure (any PVL ≥ 1000 copies/ml) were compared between those switched to dolutegravir-based ART and those remaining on PI-containing ART.

RESULTS

A total of 183 PLWH were switched to dolutegravir-based regimens and 309 remained on PI-containing regimens. The incidences of VLLV and LLV were 26.5 and 13.2 per 100 person-years of follow-up in the dolutegravir group, respectively, and 17.1 and 7.0 per 100 person-years of follow-up in the PI group; there were no statistically significant differences after adjusting for confounders. The rate of virological failure was 1.3 per 100 person-years of follow-up in the dolutegravir group and 1.9 per 100 person-years of follow-up in the PI group (p = 0.32). Neither VLLV nor LLV was related to subsequent virological failure.

CONCLUSIONS

Among virally suppressed PLWH, the risk of developing VLLV or LLV were similar between those switched to dolutegravir-based therapy and those who continued PI-based therapy. VLLV and LLV were not associated with subsequent virological failure.