The M184I/V and K65R nucleoside resistance mutations in HIV-1 prevent the emergence of resistance mutations against dolutegravir

Comprehensive database of HIV mutations selected during antiretroviral in vitro passage experiments

BACKGROUND

In vitro passage experiments are crucial to the development of antiretroviral (ARV) drugs.

METHODS

We created an online database containing data from 102 published studies in which HIV-1 or HIV-2 was cultured with increasing concentrations of the FDA-approved nucleoside RT inhibitors (NRTIs), nonnucleoside RT inhibitors (NNRTIs), integrase strand transfer inhibitors (INSTIs), protease inhibitors (PIs), capsid inhibitor (CAI) lenacapavir, and nucleoside RT translocation inhibitor (NRTTI) islatravir. We summarized the mutations selected in the subset of passage experiments with NRTIs lamivudine (3TC), emtricitabine (FTC), abacavir (ABC), tenofovir (TFV), and zidovudine (AZT), NNRTIs doravirine (DOR), efavirenz (EFV), and rilpivirine (RPV), INSTIs bictegravir (BIC), cabotegravir (CAB), and dolutegravir (DTG), and PIs atazanavir (ATV), darunavir (DRV), and lopinavir (LPV). Mutations selected in vitro were compared with those selected in persons receiving the same ARV.

RESULTS

Twenty-seven studies described 89 experiments of wildtype isolates passaged with 3TC, FTC, ABC, TFV, or AZT; sixteen studies described 89 experiments passaged with EFV, RPV, or DOR; eleven studies described 76 experiments passaged with the INSTIs BIC, CAB, or DTG; six studies described 33 experiments passaged with ATV, LPV, or DRV. With several exceptions, mutations selected in two or more experiments were among the most common mutations selected in persons receiving the same ARV.

CONCLUSIONS

We created a database of published ARV in vitro selection experiments. Mutations emerging from these experiments generally predict those observed in persons receiving the same ARV. However, there are notable differences in mutation frequencies between in vitro and in vivo 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.

Prevalence and Structure of HIV-1 Drug Resistance to Antiretrovirals in the Volga Federal District in 2008-2019

The increasing number of HIV-infected people who are receiving ART, including those with low adherence, is causing the spread of HIV drug resistance (DR). A total of 1396 plasma samples obtained from treatment-experienced patients from the Volga federal district (VFD), Russia, were examined to investigate HIV DR occurrence. The time periods 2008−2015 and 2016−2019 were compared. Fragmentary Sanger sequencing was employed to identify HIV resistance to reverse transcriptase inhibitors (RTIs) and protease inhibitors (PIs) using an ABI 3500XL genetic analyzer, a ViroSeq™ HIV-1 genotyping system (Alameda, CA, USA) and AmpliSense HIV-Resist-Seq reagent kits (Moscow, Russia). In 2016−2019, HIV DR was detected significantly more often than in 2008−2015 (p < 0.01). Mutations to RTIs retained leading positions in the structure of DR. Frequencies of resistance mutations to nucleoside and non-nucleoside RTIs (NRTIs and NNRTIs) in the spectra of detected mutations show no significant differences. Resistance to NRTIs after 2016 began to be registered more often as a part of multidrug resistance (MDR), as opposed to resistance to a single class of antiretrovirals. The frequency of DR mutations to PIs was low, both before and after 2016 (7.9% and 6.1% in the spectrum, respectively, p > 0.05). MDR registration rate became significantly higher from 2008 to 2019 (17.1% to 72.7% of patients, respectively, p < 0.01). M184V was the dominant replacement in all the years of study. A significant increase in the frequency of K65R replacement was revealed. The prevalence of integrase strand transfer inhibitor (INSTI) resistance mutations remains to be investigated.

Virologic efficacy of tenofovir, lamivudine and dolutegravir as second-line antiretroviral therapy in adults failing a tenofovir-based first-line regimen

OBJECTIVE

Recycling tenofovir and lamivudine/emtricitabine (XTC) with dolutegravir would provide a more tolerable, affordable, and scalable second-line regimen than dolutegravir with an optimized nucleoside reverse transcriptase inhibitor (NRTI) backbone. We evaluated efficacy of tenofovir/lamivudine/dolutegravir (TLD) in patients failing first-line tenofovir/XTC/efavirenz or nevirapine.

DESIGN

Single arm, prospective, interventional study.

SETTING

Two primary care clinics in Khayelitsha, South Africa.

PARTICIPANTS

Sixty adult patients with two viral loads greater than 1000 copies/ml.

INTERVENTION

Participants were switched to TLD with additional dolutegravir (50 mg) for 2 weeks to overcome efavirenz induction.

PRIMARY OUTCOME

Proportion achieving viral load less than 50 copies/ml at week 24 using the FDA snapshot algorithm.

RESULTS

Baseline median CD4+ cell count was 248 cells/μl, viral load 10 580 copies/ml and 48 of 54 (89%) had resistance (Stanford score ≥15) to one or both of tenofovir and XTC. No participants were lost to follow-up. At week 24, 51 of 60 [85%, 95% confidence interval (CI) 73-93%] were virologically suppressed, six had viral load 50-100 copies/ml, one had viral load 100-1000 copies/ml, one no viral load in window, and one switched because of tenofovir-related adverse event. No integrase mutations were detected in the one participant meeting criteria for resistance testing. Virological suppression was achieved by 29 of 35 (83%, 95% CI 66-93%) with resistance to tenofovir and XTC, 11 of 13 (85%, 95% CI 55-98%) with resistance to XTC, and six of six (100%, 95% CI 54-100%) with resistance to neither.

CONCLUSION

A high proportion of adults switching to second-line TLD achieved virologic suppression despite substantial baseline NRTI resistance and most not suppressed had low-level viraemia (≤100 copies/ml). This suggests recycling tenofovir and XTC with dolutegravir could provide an effective second-line option.

Dolutegravir Plus Lamivudine Two-Drug Regimen: Safety, Efficacy and Diagnostic Considerations for Its Use in Real-Life Clinical Practice-A Refined Approach in the COVID-19 Era

The diagnostic and therapeutic management of the Coronavirus Disease 2019 (COVID-19) pandemic in the HIV population brought some known criticalities (and opportunities) to the forefront, for both those who are facing their first therapeutic line today, and for those already well viro-suppressed. The clinical, socioeconomic, and psychological impact of the COVID-19 pandemic should not affect the long-term care of people living with HIV, which creates an urgent need to optimize the diagnostic and treatment approach to the first-line or switch regimens. The use of dolutegravir plus a lamivudine two-drug regimen is one of the most promising solutions to ease the management of HIV treatment in this difficult period. In this review, we report the most salient features related to the use of this regimen from real-life cohorts, meta-analyses, randomized clinical trials, and studies presented at international conferences up to March 2021. We focused on the diagnostic and clinical-management implications of its use in real life, and how these comply with the contingent historical situation. The issue of the timing and type of diagnostic procedures and the relevance of classical diagnostic tests (such as genotype for resistance detection) is also discussed. According to the currently available results, dolutegravir plus a lamivudine two-drug regimen represents an outstanding tool, whose expected advantages fulfill the current requirements for optimal daily care of our HIV patients.

High drug resistance levels could compromise the control of HIV infection in paediatric and adolescent population in Kinshasa, the Democratic Republic of Congo

Background

The inadequacy of HIV viraemia and resistance monitoring in Africa leads to uncontrolled circulation of HIV strains with drug resistance mutations (DRM), compromising antiretroviral therapy (ART) effectiveness. This study describes the DRM prevalence and its therapeutic impact in HIV-infected pediatric patients from Kinshasa (Democratic Republic of Congo, DRC).

Methods

From 2016–2018, dried blood were collected from 71 HIV-infected children and adolescents under ART in two hospitals in Kinshasa for HIV-1 DRM pol analysis, predicted ARV-susceptibility by Stanford and phylogenetic characterization.

Results

HIV-1 sequences were recovered from 55 children/adolescents with 14 years of median-age. All had received nucleoside and non-nucleoside reverse transcriptase inhibitors (NRTI, NNRTI), 9.1% protease inhibitors (PI) and only one integrase inhibitor (INI). Despite the use of ART, 89.1% showed virological failure and 67.3% carried viruses with major-DRM to one (12.7%), two (47.3%), or three (5.5%) ARV-families. Most children/adolescents harbored DRM to NNRTI (73.5%) or NRTI (61.2%). Major-DRM to PI was present in 8.3% and minor-DRM to INI in 15%. Dual-class-NRTI+NNRTI resistance appeared in 53.1% of patients. Viruses presented high/intermediate resistance to nevirapine (72.9% patients), efavirenz (70.9%), emtricitabine/lamivudine (47.9%), rilpivirine (41.7%), etravirine (39.6%), doravidine (33.3%), zidovudine (22.9%), among others. Most participants were susceptible to INI and PI. Great diversity of variants was found, with a high rate (40%) of unique recombinants.

Conclusion

The high DRM prevalence observed among HIV-infected children and adolescents in Kinshasa could compromise the 95-95-95-UNAIDS targets in the DRC. It also reinforces the need for routine resistance monitoring for optimal rescue therapy election in this vulnerable population to control the spread of resistant HIV in the country.

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.

Risks and benefits of reducing the number of drugs to treat HIV-1 infection

Introduction: Despite the efficacy and safety of antiretroviral therapy, new treatment options are needed to address the concerns of patients and physicians regarding long-term toxicities, costs, and convenience of lifelong antiretroviral therapy. To achieve this goal, one strategy is to reduce the number of drugs in the antiretroviral regimen.Areas covered: We review the recent evidence on the efficacy and safety of reduced drug regimens and their potential risks and benefits. There is currently strong evidence showing that some two-drug regimens have a comparable efficacy and short-term safety compared to standard three-drug regimens. The fixed-dose combination of dolutegravir/lamivudine is already an alternative for many treatment-naïve and virologically suppressed HIV-1 infected adults supported by large randomized clinical trials. The co-formulation dolutegravir plus rilpivirine is also a switch strategy for maintenance therapy. Long-acting injectable cabotegravir plus rilpivirine has already regulatory approval, and islatravir plus doravirine is an expected option in the near future. Some two-drug regimens have not been as successful.Expert opinion: Long-term safety issues of these two-drug regimens remain to be determined, but with the overwhelming evidence available in virological control and short-term safety, the potential benefits of some of these two-drug regimens appear to outweigh the risks.

AntiRetroviral Therapy In Second-line: investigating Tenofovir-lamivudine-dolutegravir (ARTIST): protocol for a randomised controlled trial

Background: Dolutegravir has superior efficacy and tolerability than lopinavir-ritonavir in second-line antiretroviral therapy after failure of a first-line non-nucleoside reverse transcriptase inhibitors-based regimen, when dolutegravir is accompanied by at least one fully active nucleoside reverse transcriptase inhibitor (NRTI). Resistance testing to select NRTIs is not feasible in low- and middle-income countries due to cost and limited laboratory capacity. Evidence suggests that recycling tenofovir plus lamivudine or emtricitabine backbone with dolutegravir could provide an effective second-line option. This study aims to determine the virologic efficacy of tenofovir-lamivudine-dolutegravir (TLD) with and without a lead-in supplementary dose of dolutegravir (to counteract the inducing effect of efavirenz) in patients failing a first-line regimen of tenofovir-emtricitabine-efavirenz (TEE). Methods: We will perform a parallel group, randomised (1:1), double blind, placebo-controlled, Phase II trial, comparing TLD fixed dose combination daily with a lead-in supplementary 50 mg dolutegravir dose versus matching placebo taken 12 hours later for the first 14 days, in patients failing a first-line TEE regimen. The trial will be set in two primary care clinics in Khayelitsha; a large, peri-urban informal settlement in Cape Town, South Africa. We will enrol 130 participants, with follow-up to 48 weeks. The primary endpoint is proportion achieving viral load <50 copies/mL at week 24 using a modified intention-to-treat analysis and the U.S. Food and Drug Administration snapshot algorithm. Secondary endpoints include virologic suppression at weeks 12 and 48, time to suppression, emergence of dolutegravir and new NRTI resistance mutations, safety, and tolerability. Discussion: Impaired viral fitness due to NRTI resistance mutations and dolutegravir's high barrier to resistance provide rationale for switching patients from a failing TEE regimen to TLD; however, clinical evidence regarding virologic efficacy is lacking. This study provides estimates of such a strategy's early virologic efficacy with and without a supplementary dolutegravir dosing. Registration: ClinicalTrials.gov NCT03991013 (19/06/2019).

A systematic review of the genetic mechanisms of dolutegravir resistance

Background

Characterizing the mutations selected by the integrase strand transfer inhibitor (INSTI) dolutegravir and their effects on susceptibility is essential for identifying viruses less likely to respond to dolutegravir therapy and for monitoring persons with virological failure (VF) on dolutegravir therapy.

Methods

We systematically reviewed dolutegravir resistance studies to identify mutations emerging under dolutegravir selection pressure, the effect of INSTI resistance mutations on in vitro dolutegravir susceptibility, and the virological efficacy of dolutegravir in antiretroviral-experienced persons.

Results and conclusions

We analysed 14 studies describing 84 in vitro passage experiments, 26 studies describing 63 persons developing VF plus INSTI resistance mutations on a dolutegravir-containing regimen, 41 studies describing dolutegravir susceptibility results, and 22 clinical trials and 16 cohort studies of dolutegravir-containing regimens. The most common INSTI resistance mutations in persons with VF on a dolutegravir-containing regimen were R263K, G118R, N155H and Q148H/R, with R263K and G118R predominating in previously INSTI-naive persons. R263K reduced dolutegravir susceptibility ∼2-fold. G118R generally reduced dolutegravir susceptibility >5-fold. The highest levels of reduced susceptibility occurred in viruses containing Q148 mutations in combination with G140 and/or E138 mutations. Dolutegravir two-drug regimens were highly effective for first-line therapy and for virologically suppressed persons provided dolutegravir’s companion drug was fully active. Dolutegravir three-drug regimens were highly effective for salvage therapy in INSTI-naive persons provided one or more of dolutegravir’s companion drugs was fully active. However, dolutegravir monotherapy in virologically suppressed persons and functional dolutegravir monotherapy in persons with active viral replication were associated with a non-trivial risk of VF plus INSTI resistance mutations.

Resistance to integrase inhibitors: a national study in HIV-1-infected treatment-naive and -experienced patients

OBJECTIVES

To describe integrase strand transfer inhibitor (INSTI) resistance profiles and factors associated with resistance in antiretroviral-naive and -experienced patients failing an INSTI-based regimen in clinical practice.

METHODS

Data were collected from patients failing an INSTI-containing regimen in a multicentre French study between 2014 and 2017. Failure was defined as two consecutive plasma viral loads (VL) >50 copies/mL. Reverse transcriptase, protease and integrase coding regions were sequenced at baseline and failure. INSTI resistance-associated mutations (RAMs) included in the Agence Nationale de Recherches sur le SIDA genotypic algorithm were investigated.

RESULTS

Among the 674 patients, 359 were failing on raltegravir, 154 on elvitegravir and 161 on dolutegravir therapy. Overall, 90% were experienced patients and 389 (58%) patients showed no INSTI RAMs at failure. The strongest factors associated with emergence of at least one INSTI mutation were high VL at failure (OR = 1.2 per 1 log10 copies/mL increase) and low genotypic sensitivity score (GSS) (OR = 0.08 for GSS ≥3 versus GSS = 0-0.5). Patients failing dolutegravir also had significantly fewer INSTI RAMs at failure than patients failing raltegravir (OR = 0.57, P = 0.02) or elvitegravir (OR = 0.45, P = 0.005). Among the 68 patients failing a first-line regimen, 11/41 (27%) patients on raltegravir, 7/18 (39%) on elvitegravir and 0/9 on dolutegravir had viruses with emergent INSTI RAMs at failure.

CONCLUSIONS

These results confirmed the robustness of dolutegravir regarding resistance selection in integrase in the case of virological failure in routine clinical care.

Rapid initiation of antiretroviral therapy at HIV diagnosis: definition, process, knowledge gaps

Initiating antiretroviral therapy (ART) as early as the day of HIV diagnosis is a strategy of increasing global interest to control the HIV epidemic and optimize the health of people living with HIV (PLWH). No detrimental effects of rapid-start ART have been identified in randomized controlled trials undertaken in low- or middle-income countries, or in cohort studies performed in high-income countries. Rapid-start ART may be a key approach in reaching the 2020 Joint United Nations Programme on HIV/AIDS goal of 90% of all PLWH knowing their status, 90% of those diagnosed receiving sustained ART, and 90% of those receiving ART achieving viral suppression; it may also be important for achieving the suggested fourth "90%" goal: improving health-related quality-of-life in PLWH. Presently there is insufficient broad evidence for guidelines to recommend universal test-and-treat strategies for all people, in all settings, at HIV diagnosis; consequently, there is a pressing need to conduct high-quality studies that investigate immediate ART initiation. This article evaluates global evidence regarding rapid-start ART, including same-day start, with particular focus on the implementation of this strategy in high-income countries.

Dolutegravir plus lamivudine for maintenance of HIV viral suppression in adults with and without historical resistance to lamivudine: 48-week results of a non-randomized, pilot clinical trial (ART-PRO)

BACKGROUND

We investigated the efficacy of a switch to dolutegravir plus lamivudine in aviremic individuals without evidence of persistent lamivudine resistance-associated mutations in baseline proviral DNA population sequencing.

METHODS

Open-label, single-arm, 48-week pilot trial. HIV-1 infected adults, naïve to integrase inhibitors, with CD4+ above 350 cell/μL and fewer than 50 HIV-1 RNA copies per mL the year prior to study entry switched to dolutegravir plus lamivudine. Participants were excluded if baseline proviral DNA population genotyping detected lamivudine resistance-associated mutations. To detect resistance minority variants, proviral DNA next-generation sequencing was retrospectively performed from baseline samples. Primary efficacy endpoint was proportion of participants with fewer than 50 HIV-1 RNA copies per mL at week 48. Safety and tolerability outcomes were incidence of adverse events and treatment discontinuations. ART-PRO is registered with ClinicalTrials.gov, NCT03539224.

FINDINGS

41 participants switched to dolutegravir plus lamivudine, 21 with lamivudine resistance mutations in historical plasma genotypes. Baseline next-generation sequencing detected lamivudine resistance mutations (M184V/I and/or K65R/E/N) over a 5% threshold in 15/21 (71·4%) and 3/20 (15%) of participants with and without history of lamivudine resistance, respectively. At week 48, 92·7% of participants (38/41) had fewer than 50 HIV-1 RNA copies per mL. There were no cases of virologic failure. Three participants with historical lamivudine resistance were prematurely discontinued from the study (2 protocol violations, one adverse event). Ten participants (4 in the group with historical lamivudine resistance) had a transient viral rebound, all resuppressed on dolutegravir plus lamivudine. There were 28 drug-related adverse events, only one leading to discontinuation.

INTERPRETATION

In this pilot trial, dolutegravir plus lamivudine was effective in maintaining virologic control despite past historical lamivudine resistance and presence of archived lamivudine resistance-associated mutations detected by next generation sequencing. Further studies are needed to confirm our results.

FUNDING

Fondo de Investigaciones Sanitarias, Instituto de Salud Carlos III PI16/00837-PI16/00678.

Continuation of emtricitabine/lamivudine within combination antiretroviral therapy following detection of the M184V/I HIV-1 resistance mutation

OBJECTIVES

The aim of the study was to investigate whether lamivudine (3TC) or emtricitabine (FTC) use following detection of M184V/I is associated with better virological outcomes.

METHODS

We identified people with viruses harbouring the M184V/I mutation in UK multicentre data sets who had treatment change/initiation within 1 year. We analysed outcomes of viral suppression (< 200 HIV-1 RNA copies/mL) and appearance of new major drug resistance mutations (DRMs) using Cox and Poisson models, with stratification by new drug regimen (excluding 3TC/FTC) and Bayesian implementation, and estimated the effect of 3TC/FTC adjusted for individual and viral characteristics.

RESULTS

We included 2597 people with the M184V/I resistance mutation, of whom 665 (25.6%) were on 3TC and 458 (17.6%) on FTC. We found a negative adjusted association between 3TC/FTC use and viral suppression [hazard ratio (HR) 0.84; 95% credibility interval (CrI) 0.71-0.98]. On subgroup analysis of individual drugs, there was no evidence of an association with viral suppression for 3TC (n = 184; HR 0.94; 95% CrI 0.73-1.15) or FTC (n = 454; HR 0.99; 95% CrI 0.80-1.19) amongst those on tenofovir-containing regimens, but we estimated a reduced rate of viral suppression for people on 3TC amongst those without tenofovir use (n = 481; HR 0.71; 95% CrI 0.54-0.90). We found no association between 3TC/FTC and detection of any new DRM (overall HR 0.92; 95% CrI 0.64-1.18), but found inconclusive evidence of a lower incidence rate of new DRMs (overall incidence rate ratio 0.69; 95% CrI 0.34-1.11).

CONCLUSIONS

We did not find evidence that 3TC or FTC use is associated with an increase in viral suppression, but it may reduce the appearance of additional DRMs in people with M184V/I. 3TC was associated with reduced viral suppression amongst people on regimens without tenofovir.

Prevalence of acquired drug resistance mutations in antiretroviral- experiencing subjects from 2012 to 2017 in Hunan Province of central South China

BACKGROUND

There are few data on the prevalence of acquired drug resistance mutations (ADRs) in Hunan Province, China, that could affect the effectiveness of antiretroviral therapy (ART).

OBJECTIVES

The main objectives of this study were to determine the prevalence of acquired drug resistance (ADR) the epidemic characteristics of HIV-1-resistant strains among ART-failed HIV patients in Hunan Province, China.

METHODS

ART-experienced and virus suppression failure subjects in Hunan between 2012 and 2017 were evaluated by genotyping analysis and mutations were scored using the HIVdb.stanford.edu algorithm to infer drug susceptibility.

RESULTS

The prevalence of HIV-1 ADR were 2.76, 2.30, 2.98, 2.62, 2.23and 2.17%, respectively, from 2012 to 2017. Overall 2295 sequences were completed from 2932 ART-failure patients, and 914 of these sequences were found to have drug resistance mutation. The most common subtype was AE (64.14%), followed by BC (17.91%) and B (11.50%). Among those 914 patients with drug resistance mutations,93.11% had NNRTI-associated drug resistance mutations, 74.40% had NRTI drug resistance mutations (DRMs) and 6.89% had PI DRMs. Dual-class mutations were observed in 591 (64.66%) cases, and triple-class mutations were observed in 43 (4.70%) cases. M184V (62.04%), K103N (41.90%) and I54L (3.83%) were the most common observed mutations, respectively, in NRTI-, NNRTI- and PI-associated drug resistance. 93.76% subjects who had DRMs received the ART first-line regimens. CD4 count, symptoms in the past 3 months, and ART adherence were found to be associated with HIV-1 DR.

CONCLUSIONS

This study showed that although the prevalence of HIV-acquired resistance in Hunan Province is at a low-level, the long-term and continuous surveillance of HIV ADR in antiretroviral drugs (ARVs) patients is necessary.

Retrospective study on the outcome of two-drug regimens based on dolutegravir plus one reverse transcriptase inhibitor in virologically-suppressed HIV-infected patients

This was a retrospective study on the efficacy and drug resistance mutations selected at virological failure (VF) in prospectively-followed HIV-infected patients switched to dolutegravir plus rilpivirine (DTG+RPV) or lamivudine (DTG+3TC) while virologically suppressed (HIV-RNA <50 copies/mL). VF was defined as HIV-RNA >50 copies/mL in two consecutive determinations or in a single determination if followed by treatment modification, or >1000 copies/mL in a single determination. Totally, 374 patients were analysed (307 switched to DTG+3TC and 67 to DTG+RPV); 220 had documented historical resistance. The median (IQR) time with HIV-RNA <50 copies/mL before switch was 4.52 (1.93-8.14) years. VF occurred in 17 patients after a median of 1.74 (0.90-2.46) years of follow-up in the 3TC group [incidence rate (95% CI) 3.34 (2.08-5.37) per 100-PYFU] and in 2 patients after a median of 1.78 (1.10-2.99) years of follow-up in the RPV group [incidence rate (95% CI) 1.57 (0.4-6.28) per 100-PYFU]. The 48-week estimated probabilities to maintain virological suppression during treatment with a two-drug regimen were 97.8% (95% CI 95.1-99.0%) vs. 98.3% (95% CI 88.6-99.8%) in the 3TC versus RPV group (P = 0.311). At switch, patients with VF had undetectable HIV-RNA since 0.71 (0.23-1.07) years versus 1.49 (0.64-2.2) years in those without VF (P = 0.001). In the 3TC group, VF was not associated with the presence of historical resistance to nucleoside analogues, and DTG-resistant variants were not selected at VF. One VF to DTG+RPV occurred because of historical resistance to RPV, accompanied by newly selected G140A and Q148R mutations. VF was infrequent with these regimens and was negatively associated with duration of viral undetectability. Drug resistance mutations selected at failure of these regimens were those expected in case of failure of any regimen including DTG, 3TC or RPV, but the impact of resistance to NRTIs on efficacy of DTG+3TC seems lower than expected.

Barrier to Resistance of Dolutegravir in Two-Drug Combinations

A major concern when using two-drug anti-HIV regimens is the risk of viral resistance. However, no techniques to evaluate the barrier to resistance of two-drug combinations in vitro have been reported. We evaluated the emergence of drug-resistant mutants in a passage study with constant concentrations of two drugs simultaneously. The barrier to resistance of dolutegravir-containing two-drug combinations was higher than the other combinations evaluated in this study.

Efficacy and tolerability of lamivudine plus dolutegravir compared with lamivudine plus boosted PIs in HIV-1 positive individuals with virologic suppression: a retrospective study from the clinical practice

BACKGROUND

Direct comparisons between lamivudine plus bPIs and lamivudine plus dolutegravir as maintenance strategies in virologically-suppressed HIV positive patients are lacking.

METHODS

Time to treatment discontinuation (TD) and virological failure (VF) were compared in a cohort of HIV+ patients on a virologically-effective ART starting lamivudine with either darunavir/r, atazanavir/r or dolutegravir. Changes in laboratory parameters were also evaluated.

RESULTS

Four-hundred-ninety-four patients were analyzed (170 switching to darunavir/r, 141 to atazanavir/r, 183 to dolutegravir): median age was 49 years, with 8 years since ART start. Groups differed for age, HIV-risk factor, time since HIV-diagnosis and on ART, previous therapy and reasons for switching. Estimated proportions free from TD at week 48 and 96 were 79.8 and 48.3% of patients with darunavir/r, 87.0 and 70.9% with atazanavir/r, and 88.2 and 82.6% with dolutegravir, respectively (p < 0.001). Calendar years, HIV-risk factor, higher baseline cholesterol and an InSTI-based previous regimen predicted TD, whereas lamivudine+dolutegravir therapy and previous tenofovir use were protective. VF was the cause of TD in 6/123 cases with darunavir/r, 4/97 with atazanavir/r and 3/21 with dolutegravir. Other main reasons for TD were: toxicity (43.1% with darunavir/r, 39.2% with atazanavir/r, 52.4% with dolutegravir), further simplification (36.6% with darunavir/r, 30.9% with atazanavir/r, 14.3% with dolutegravir). Incidence of VF did not differ among study groups (p = 0.747). No factor could predict VF. Lipid profile improved in the dolutegravir group, whereas renal function improved in the bPIs groups.

CONCLUSIONS

In real practice, a switch to lamivudine+dolutegravir showed similar efficacy but longer durability than a switch to lamivudine+bPIs.

Virologic failure and HIV drug resistance on simplified, dolutegravir-based maintenance therapy: Systematic review and meta-analysis

Background: Dolutegravir-containing maintenance therapy is a promising simplification strategy for virologically suppressed HIV-infected individuals. However, most of the available data to inform this strategy come from small, uncontrolled studies. We estimated the proportion of HIV-infected patients experiencing virological failure (VF) and developing drug resistance on dolutegravir (DTG)-based maintenance therapy. Methods: We searched Medline, Embase, Cochrane Central, Web of Science, and conference abstracts for studies assessing VF on DTG-based maintenance therapy. Studies including ≥5 adults with an undetectable viral load on antiretroviral therapy (ART) who switched to a DTG-based mono- or dual therapy were included. Pooled proportions of VF were estimated using random-intercept logistic meta-regression and acquired drug resistance mutations described for each strategy. Results: Of 1719 studies considered, 21 met our selection criteria, including seven interventional and 14 observational studies. Eight studies including 251 patients assessed VF on DTG monotherapy and fourteen studies including 1670 participants VF on dual therapy. The participant's median age ranged from 43 to 63 years, their median nadir CD4 count from 90 to 399 cells/µl, and 27.6% were female. The proportion of participants experiencing VF on DTG-monotherapy was 3.6% (95% confidence interval [CI] 1.9-6.7) at 24 weeks and 8.9% (95% CI 4.7-16.2) at 48 weeks. Resistance mutations developed in seven (3.6%) participants on DTG-monotherapy. Among patients on dual therapy, ten (0.7%, 95% CI 0.4-1.3) experienced VF by 48 weeks and none developed resistance to DTG. In adjusted analyses, VF at 24 weeks was less likely on dual therapy than on monotherapy (adjusted odds ratio: 0.10, 95% CI 0.03-0.30). Conclusions: Whereas VF is relatively common on DTG maintenance monotherapy, DTG-based dual therapy appears to be a promising simplification strategy for individuals with a suppressed HIV viral load on triple-ART.

Virologic failure and HIV drug resistance on simplified, dolutegravir-based maintenance therapy: Systematic review and meta-analysis

Background: Dolutegravir-containing maintenance therapy is a promising simplification strategy for virologically suppressed HIV-infected individuals. However, most of the available data to inform this strategy come from small, uncontrolled studies. We estimated the proportion of HIV-infected patients experiencing virological failure (VF) and developing drug resistance on dolutegravir (DTG)-based maintenance therapy. Methods: We searched Medline, Embase, Cochrane Central, Web of Science, and conference abstracts for studies assessing VF on DTG-based maintenance therapy. Studies including ≥5 adults with an undetectable viral load on antiretroviral therapy (ART) who switched to a DTG-based mono- or dual therapy were included. Pooled proportions of VF were estimated using random-intercept logistic meta-regression and acquired drug resistance mutations described for each strategy. Results: Of 1719 studies considered, 21 met our selection criteria, including seven interventional and 14 observational studies. Eight studies including 251 patients assessed VF on DTG monotherapy and fourteen studies including 1670 participants VF on dual therapy. The participant's median age ranged from 43 to 63 years, their median nadir CD4 count from 90 to 399 cells/µl, and 27.6% were female. The proportion of participants experiencing VF on DTG-monotherapy was 3.6% (95% confidence interval [CI] 1.9-6.7) at 24 weeks and 8.9% (95% CI 4.7-16.2) at 48 weeks. Resistance mutations developed in seven (3.6%) participants on DTG-monotherapy. Among patients on dual therapy, ten (0.7%, 95% CI 0.4-1.3) experienced VF by 48 weeks and none developed resistance to DTG. In adjusted analyses, VF at 24 weeks was less likely on dual therapy than on monotherapy (adjusted odds ratio: 0.10, 95% CI 0.03-0.30). Conclusions: Whereas VF is relatively common on DTG maintenance monotherapy, DTG-based dual therapy appears to be a promising simplification strategy for individuals with a suppressed HIV viral load on triple-ART.

HIV-1 DNA ultra-deep sequencing analysis at initiation of the dual therapy dolutegravir + lamivudine in the maintenance DOLULAM pilot study

Background

The DOLULAM study assessed the efficacy of dolutegravir + lamivudine dual therapy to maintain virological suppression in heavily treatment-experienced HIV-1-infected adults. No virological failure occurred during the first year of the dual therapy.

Objectives

A virological substudy was conducted to assess the prevalence of M184I/V mutations at dual therapy initiation using historical DNA/RNA genotypes and baseline DNA genotype obtained by next-generation sequencing (NGS).

Methods

HIV-1 RT sequences were obtained from DNA and/or historical RNA using Sanger technology. HIV-1 DNA RT and integrase NGS was performed using Illumina® technology.

Results

Among the 27 patients enrolled in the DOLULAM study, historical HIV DNA and RNA Sanger sequences were available in 14 and 18 patients, respectively. At the initiation of DOLULAM, DNA NGS genotypes showed that 45% and 21% of the patients harboured minority resistant variants (MRV) in RT and integrase, respectively. Combining all available genotype data, an M184I/V was observed in 17 of 27 (63%) of the patients. Most M184V were detected in historical RNA genotypes (n = 8 of 11), whereas M184I were exclusively detected in DNA genotypes (n = 10, including 7 as MRV). Ten patients displayed defective viral genomes in cellular reservoirs, all including M184I and stop codons. At the time of DOLULAM initiation, M184V was observed in DNA NGS in five patients, including one as MRV.

Conclusions

These first NGS data on HIV DNA at initiation of a switch study showed (i) a high proportion of patients harbouring defective viral genomes, whose mutation M184I is a marker, and (ii) a low number of patients in whom M184V remained as a major viral variant in PBMCs.

Impact of the M184V Resistance Mutation on Virological Efficacy and Durability of Lamivudine-Based Dual Antiretroviral Regimens as Maintenance Therapy in Individuals With Suppressed HIV-1 RNA: A Cohort Study

Background

Dual therapy (DT) with boosted protease inhibitors (bPIs) plus lamivudine has been shown to be superior to bPI monotherapy in virologically suppressed patients despite previous selection of the lamivudine resistance M184V mutation. We compared the virological efficacy of lamivudine-based DT in patients with and without a history of M184V detection.

Methods

We retrospectively analyzed patients with HIV-RNA ≤50 copies/mL switching to DT with at least 1 previous resistance genotype in the ARCA database. Time to virological failure (VF; HIV-RNA ≥200 copies/mL or 2 consecutive HIV-RNA >50 copies/mL) and to treatment discontinuation (TD) was analyzed by survival analysis.

Results

Four hundred thirty-six patients switching to lamivudine plus bPIs (70%) or integrase inhibitors (30%) were included. Patients with M184V (n = 87) were older, had lower nadir CD4+ cell count, longer duration of antiretroviral therapy and of virologic suppression, and higher rate of hepatitis C virus infection compared with patients without M184V. The 3-year probability of remaining free from VF was 91.9% (95% confidence interval [CI], 86.6–97.2) without M184V and 87.8% (95% CI, 78.4–97.2) with M184V (P = .323). The time to TD did not differ between groups. Multivariate analysis adjusting for baseline variables differing between groups also did not detect M184V as being associated with VF or TD; however, the 3-year probability of remaining free of viral blips (isolated HIV-RNA 51–199 copies/mL) was 79.8% (95% CI, 67.8%–91.8%) with M184V vs 90.1% (95% CI, 84.0%–96.2%) without M184V (P = .016).

Conclusions

Previous selection of M184V did not increase the risk of VF or TD with lamivudine-based DT but was associated with a higher probability of viral blips.

High Prevalence of Drug Resistance Mutations Among Patients Failing First-Line Antiretroviral Therapy and Predictors of Virological Response 24 Weeks After Switch to Second-Line Therapy in São Paulo State, Brazil

Universal antiretroviral treatment with sustained viral suppression benefits patients and reduces HIV transmission. Effectiveness of therapy may be limited by antiretroviral drug resistance. Information on the resistance profile at treatment failure and its impact on antiretroviral drugs may subsidize subsequent treatment strategies. Partial pol sequences from 319 patients failing first-line therapy were analyzed for resistance associated mutations (RAMs) and HIV subtype. Demographic data, CD4 T cell count, viral load, and antiretroviral regimens and mutational profile at first-line failure were also investigated for associations to the response to second-line regimens. RAMs at the reverse transcriptase gene were frequent. Most sequences (88%) showed at least one mutation. A higher number of reverse transcriptase RAMs were associated to lower CD4 T cell counts and the use of tenofovir/lamivudine in first line. Among 205 with follow-up data, 76.6% were virally suppressed (below 200 copies/ml) after 24 weeks of second-line therapy. Most cases initiated second line with a regimen genotypic susceptibility score ≥2, but it did not predict viral suppression, that was independently associated with higher CD4 T cell counts and with the presence of nucleos(t)ide analog reverse transcriptase inhibitor (NRTI) RAMs. This study documented extensive resistance at first-line failure in this area in Brazil, highlights the risks of low CD4 T cell counts to second-line therapy, and supports the notion that recycled NRTIs may contribute to viral suppression even when genotypic resistance is present.

Effect of dolutegravir in combination with Nucleoside Reverse Transcriptase Inhibitors (NRTIs) on people living with HIV who have pre-existing NRTI mutations

Until the introduction of dolutegravir (DTG), people living with HIV (PLWH) who have developed nucleoside reverse transcriptase inhibitor (NRTI) mutations have had few other treatment options outside of regimens based on ritonavir-boosted protease inhibitors (PI/r). Here we report treatment results among PLWH in Sweden with pre-existing NRTI mutations on antiretroviral treatment (ART) with DTG and one to two NRTIs. All PLWH on ART with DTG and one to two NRTIs with pre-existing NRTI mutations were retrospectively identified from the National InfCare HIV database. As controls, PLWH on PI/r and one to two NRTIs, matched according to Genotypic Susceptibility Score and observation time, were included. Data were collected as long as the study population was on treatment with DTG; controls were monitored for the same interval. Outcome was classified as either treatment success or failure. In total, 244 participants (122 individuals treated with DTG and 122 individuals treated with PI/r) were included. Median observation time was 78 weeks (interquartile range 50-98 weeks) for participants on DTG and 75 weeks (50-101 weeks) for individuals on PI/r. Viral failure was detected in four individuals treated with DTG and three individuals treated with PI/r, resulting in similar success rates of 96.7% and 97.5%, respectively. No new mutations were found among participants with treatment failure. DTG in combination with one to two NRTIs was as efficient as PI/r in individuals with pre-existing NRTI mutations in this setting. It may be considered an alternative to PI/r-based ART even in the presence of NRTI resistance.

Efficacy and tolerance of dolutegravir-based combined ART in perinatally HIV-1-infected adolescents: a French multicentre retrospective study

Objectives

To assess the safety and efficacy of a dolutegravir-based regimen in perinatally HIV-1-infected adolescents.

Patients and methods

We conducted a retrospective multicentre study of 50 adolescents beginning dolutegravir-based treatment regimens between January 2014 and December 2015. Clinical and biological data collected before and after dolutegravir initiation were analysed. The primary endpoint was the proportion of patients achieving a plasma viral load (PVL) <50 copies/mL within 3 months of dolutegravir initiation (for patients with detectable viraemia at baseline) and maintaining virological suppression (PVL <50 copies/mL) until the last follow-up visit (for all patients).

Results

Virological suppression was noted for 17/50 adolescents at baseline. Dolutegravir-based regimens maintained virological success in 14/17 patients (82%). The other three patients experienced a transient viral rebound, before PVL fell to < 50 copies/mL again, with no need to change the antiretroviral regimen. Thirty-three viraemic adolescents were enrolled. All but one had already received antiretroviral drugs. Virological success was achieved and maintained in 19/33 subjects (58%). Another three adolescents with initial virological failure had an undetectable PVL at the end of follow-up, with reinforced measures to improve compliance. Overall, sustained virological success was observed in 66% of patients and 78% of patients had an undetectable PVL at the last visit. Dolutegravir was well tolerated. Only one patient stopped treatment for severe drug-related adverse effects (dizziness and sleep disturbance). No emergence of resistance mutations was observed in patients with virological failure.

Conclusions

Dolutegravir was safe and virologically effective in these patients, for whom multiple interventions were required to improve compliance.