Five Years With Dolutegravir Plus Lamivudine as a Switch Strategy: Much More Than a Positive Finding

Incorporating temporal dynamics of mutations to enhance the prediction capability of antiretroviral therapy's outcome for HIV-1

MOTIVATION

In predicting HIV therapy outcomes, a critical clinical question is whether using historical information can enhance predictive capabilities compared with current or latest available data analysis. This study analyses whether historical knowledge, which includes viral mutations detected in all genotypic tests before therapy, their temporal occurrence, and concomitant viral load measurements, can bring improvements. We introduce a method to weigh mutations, considering the previously enumerated factors and the reference mutation-drug Stanford resistance tables. We compare a model encompassing history (H) with one not using this information (NH).

RESULTS

The H-model demonstrates superior discriminative ability, with a higher ROC-AUC score (76.34%) than the NH-model (74.98%). Wilcoxon test results confirm significant improvement of predictive accuracy for treatment outcomes through incorporating historical information. The increased performance of the H-model might be attributed to its consideration of latent HIV reservoirs, probably obtained when leveraging historical information. The findings emphasize the importance of temporal dynamics in acquiring mutations. However, our result also shows that prediction accuracy remains relatively high even when no historical information is available.

AVAILABILITY AND IMPLEMENTATION

This analysis was conducted using the Euresist Integrated DataBase (EIDB). For further validation, we encourage reproducing this study with the latest release of the EIDB, which can be accessed upon request through the Euresist Network.

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.

Dolutegravir/Lamivudine Is Noninferior to Continuing Dolutegravir- and Non-Dolutegravir-Based Triple-Drug Antiretroviral Therapy in Virologically Suppressed People With Human Immunodeficiency Virus: DUALING Prospective Nationwide Matched Cohort Study

Background

Confirming the efficacy of dolutegravir/lamivudine in clinical practice solidifies recommendations on its use.

Methods

Prospective cohort study (DUALING) in 24 human immunodeficiency virus (HIV) treatment centers in the Netherlands. HIV RNA-suppressed cases were on triple-drug antiretroviral regimens without prior virological failure or resistance and started dolutegravir/lamivudine. Cases were 1:2 matched to controls on triple-drug antiretroviral regimens by the use of dolutegravir-based regimens, age, sex, transmission route, CD4+ T-cell nadir, and HIV RNA zenith. The primary endpoint was the treatment failure rate in cases versus controls at 1 year by intention-to-treat and on-treatment analyses with 5% noninferiority margin.

Results

The 2040 participants were 680 cases and 1380 controls. Treatment failure in the 390 dolutegravir-based cases versus controls occurred in 8.72% and 12.50% (difference: -3.78% [95% confidence interval {CI}, -7.49% to .08%]) by intention-to-treat and 1.39% and 0.80% (difference: 0.59% [95% CI, -.80% to 1.98%]) by on-treatment analyses. The treatment failure risk in 290 non-dolutegravir-based cases was also noninferior to controls. Antiretroviral regimen modifications unrelated to virological failure explained the higher treatment failure rate by intention-to-treat. A shorter time on triple-drug antiretroviral therapy and being of non-Western origin was associated with treatment failure. Treatment failure, defined as 2 consecutive HIV RNA >50 copies/mL, occurred in 4 cases and 5 controls but without genotypic resistance detected. Viral blips occured comparable in cases and controls but cases gained more weight, especially when tenofovir-based regimens were discontinued.

Conclusions

In routine care, dolutegravir/lamivudine was noninferior to continuing triple-drug antiretroviral regimens after 1 year, supporting the use of dolutegravir/lamivudine in clinical practice.

Clinical Trials Registration

NCT04707326.

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.

The DoDo experience: an alternative antiretroviral 2-drug regimen of doravirine and dolutegravir

BACKGROUND

Currently available antiretroviral 2-drug regimen (2DR) fixed dose combinations may not be suitable for specific situations including the presence of resistance associated mutations (RAM) or drug - drug interactions (DDI). The data on the use of the non-nucleoside reverse transcriptase inhibitor doravirine (DOR) and the integrase inhibitor dolutegravir (DTG) as an alternative 2DR remain scarce.

METHODS

People living with HIV with DOR + DTG as a 2DR are being followed in a prospective observational study.

RESULTS

This analysis describes 85 participants with a median age of 57 years. Median CD4-nadir was 173/µl and a majority (66%) had a history of HIV-associated or AIDS-defining conditions. Antiretroviral history was mostly extensive, and documentation of RAM was frequent. The main reasons for choosing DOR + DTG were DDI (29%), tolerability (25%), and cardiovascular risk reduction (21%). Plasma viral load at switch was < 50 copies/ml in all but 3 instances, median CD4 count was 600/µl. DOR + DTG was later changed to another regimen in 10 participants after a median of 265 days, the other 75 participants have remained on DOR + DTG for a median of 947 days.

CONCLUSION

DOR + DTG as a 2DR proved to be a durable treatment option even in extensively pretreated individuals.

Three-year efficacy of switching to dolutegravir plus lamivudine: A real-world study

BACKGROUND

Dolutegravir (DTG) plus lamivudine (3TC) has proven highly efficacious as a switching strategy in virologically suppressed people with HIV (PWH). As this strategy was introduced relatively recently, real-world, long-term durability studies are lacking.

METHODS

We performed a retrospective review of treatment-experienced patients who started DTG + 3TC in a cohort of PWH. HIV-RNA <50 copies/mL was analysed at 144 weeks in an intention-to-treat (ITT) analysis (missing = failure) and a per-protocol (PP) analysis (patients with missing data or changes for reasons other than virological failure were excluded).

RESULTS

The study population comprised 358 PWH (19% women). Median age and time with HIV infection were 51.7 and 13.4 years, respectively. The median number of previous antiretroviral combinations was three. Previous virological failure was reported in 27.1% of patients, and the M184V resistance mutation was detected in 17 patients. At 144 weeks, the percentage of individuals with HIV-RNA <50 copies/mL was 77.4% (277/358) in the ITT analysis and 95.5% (277/290) in the PP analysis. A total of 68 participants were excluded from the PP analysis (data missing, 25, discontinuation due to toxicity, 19; other, 16; death, 8). Two people with virological failure selected resistance-associated mutations (M184V and M184V + R263K). HIV-RNA remained undetectable in 17 patients with a previous history of the M184V mutation.

CONCLUSION

Our results confirm the real-world, long-term efficacy, tolerability and high genetic barrier of DTG + 3TC in treatment-experienced PWH. Although scarce, mutations causing resistance to nucleosides and integrase can emerge.

Real-Life Experience on Dolutegravir and Lamivudine as Initial or Switch Therapy in a Silver Population Living with HIV

BACKGROUND

Clinical trials and real-life studies have granted the efficacy and safety of dolutegravir and lamivudine (DTG/3TC) in naïve and experienced people living with HIV (PLWH), but there are no long-term data in elderly people. We herein describe our real-life cohort of PLWH who were ≥65 years of age (PLWH ≥ 65) who started or were switched to DTG/3TC, single-tablet regimen, or DTG plus 3TC.

METHODS

We considered laboratory/clinical parameter changes from the baseline to the last follow-up time point available for each person by the paired Wilcoxon test and analyzed factors associated with virological failure (VF) and discontinuation.

RESULTS

We included 112 PLWH with a median age of 66 (IQR: 65-70) years, 77.6% males; 84.8% of people had multimorbidity, 34.8% were on polypharmacy, and only 5.4% were naïve to treatment. Reasons to be switched to DTG/3TC were: abacavir removal (38.7%), treatment simplification (33.1%), and PI discontinuation (28.2%). The median treatment durability was 6 (IQR: 5.4-7) years. No significant changes were detected in metabolic, renal, immunological, or cardiovascular biomarkers during follow-up. HIV RNA undetectability was maintained in 104 (92.8%) individuals for whom follow-up evaluation was available. We observed eight discontinuations (two deaths, two VFs, two early intolerances, one significant weight gain, and one switch to long-acting therapy). No factors were significantly associated with VF or discontinuation.

CONCLUSIONS

This is the first study on DTG/3TC in PLWH ≥ 65 with a follow-up longer than 5 years. DTG/3TC was found to be safe and effective, neutral on metabolic parameters, and with a low discontinuation rate for toxicity or VF.

Laboratory Based Surveillance of HIV-1 Acquired Drug Resistance in Cameroon: Implications for Use of Tenofovir-Lamivudine-Dolutegravir (TLD) as Second- or Third-Line Regimens

Increased HIV drug resistance (HIVDR) with antiretroviral therapy (ART) rollout may jeopardize therapeutic options, especially in this era of transition to fixed-dose tenofovir-lamivudine-dolutegravir (TLD). We studied acquired HIVDR (ADR) patterns and describe potentially active drugs after first- and second-line failure in resource-limited settings (RLS) like Cameroon. A laboratory-based study with 759 patients (≥15 years) experiencing virological failure was carried out at the Chantal Biya International Reference Centre (CIRCB), Yaoundé, Cameroon. Socio-demographic, therapeutic and immunovirological data from patient records were analysed according to HIV-1 genotypic profiles. Median (IQR) ART-duration was 63 (50-308) months. Median CD4 and viremia were 153 (IQR:50-308) cells/mm3 and 138,666 (IQR:28,979-533,066) copies/mL, respectively. Overall ADR was high (93.4% first-line; 92.9%-second-line). TDF, potentially active in 35.7% of participants after first-line and 45.1% after second-line, suggested sub-optimal TLD-efficacy in second-line (64.3%) and third-line (54.9%). All PI/r preserved high efficacy after first-line failure while only DRV/r preserved high-level efficacy (87.9%) after second-line failure. In this resource-limited setting (RLS), ADR is high in ART-failing patients. PI/r strategies remain potent backbones for second-line ART, while only DRV/r remains very potent despite second-line failure. Though TLD use would be preferable, blind use for second- and third-line regimens may be sub-optimal (functional monotherapy with dolutegravir) with high risk of further failure, thus suggesting strategies for selective ART switch to TLD in failing patients in RLS.

Special Issue "Efficacy and Safety of Antiviral Therapy"

This comprehensive collection of papers contains a wide range of studies and observations centered on antiviral therapies, with a particular focus on HIV and other viral infections such as monkeypox and SARS-CoV-2 [...].

Assessing the Virologic Impact of Archived Resistance in the Dolutegravir/Lamivudine 2-Drug Regimen HIV-1 Switch Study TANGO through Week 144

The TANGO study (ClinicalTrials.gov, NCT03446573) demonstrated that switching to dolutegravir/lamivudine (DTG/3TC) was non-inferior to continuing tenofovir alafenamide-based regimens (TBR) through week 144. Retrospective baseline proviral DNA genotypes were performed for 734 participants (post-hoc analysis) to assess the impact of archived, pre-existing drug resistance on 144-week virologic outcomes by last on-treatment viral load (VL) and Snapshot. A total of 320 (86%) participants on DTG/3TC and 318 (85%) on TBR had both proviral genotype data and ≥1 on-treatment post-baseline VL results and were defined as the proviral DNA resistance analysis population. Archived International AIDS Society-USA major nucleoside reverse transcriptase inhibitor, non-nucleoside reverse transcriptase inhibitor, protease inhibitor, and integrase strand transfer inhibitor resistance-associated mutations (RAMs) were observed in 42 (7%), 90 (14%), 42 (7%), and 11 (2%) participants, respectively, across both groups; 469 (74%) had no major RAMs at baseline. M184V/I (1%), K65N/R (<1%), and thymidine analogue mutations (2%) were infrequent. Through week 144, >99% of participants on DTG/3TC and 99% on TBR were virologically suppressed (last on-treatment VL <50 copies/mL) regardless of the presence of major RAMs. Results from the sensitivity analysis by Snapshot were consistent with the last available on-treatment VL. In TANGO, archived, pre-existing major RAMs did not impact virologic outcomes through week 144.

Neuropsychiatric adverse drug reactions and associated factors in a cohort of individuals starting dolutegravir-based or efavirenz-based antiretroviral therapy in Belo Horizonte, Brazil

OBJECTIVE

To measure the incidence of neuropsychiatric adverse drug reactions (ADRs) in individuals living with HIV who initiated antiretroviral therapy (ART) with first-line regimens containing dolutegravir (DTG) or efavirenz (EFV) and associated factors.

METHODS

Prospective cohort study with individuals living with HIV who started ART with DTG or EFV associated with tenofovir disoproxil and lamivudine in Belo Horizonte, Brazil. Sociodemographic, clinical, and laboratory data were collected from September 2015 to October 2018 in three specialized HIV care services through interviews, clinical records, and computerized systems. We analysed the frequency of neuropsychiatric ADRs recorded in clinical records 12 months after starting antiretroviral use, and the associated factors were investigated using binary logistic regression.

RESULTS

A total of 152 (35.1%) of the 433 individuals included had neuropsychiatric ADRs. The incidence density was 35.3/100 person-years. The subjects mainly had sleep disorders and disturbances (21.3%), neurological disorders (13.9%), headaches (8.1%), and anxiety disorders and symptoms (3.0%), more frequently in individuals using EFV. A lower likelihood of neuropsychiatric ADRs was associated with using a DTG-based antiretroviral regimen (OR = 0.24; 95% CI = 0.14-0.40) and anxiety or depression signs and symptoms at the onset of treatment (OR = 0.57; 95% CI = 0.37-0.89).

CONCLUSION

The incidence of neuropsychiatric ADRs was high in individuals starting ART with a lower likelihood of using a DTG-based regimen. The DTG-based regimen had a better safety profile for neuropsychiatric ADRs than the EFV-based regimen.

Analysing the efficacy and tolerability of dolutegravir plus either rilpivirine or lamivudine in a multicentre cohort of virologically suppressed PLWHIV

OBJECTIVES

We aimed to investigate and compare the efficacy and safety of two dolutegravir-based two-drug regimens: dolutegravir + lamivudine versus dolutegravir + rilpivirine.

METHODS

We analysed a cohort of people living with HIV (PLWHIV) switching to dolutegravir + lamivudine or dolutegravir + rilpivirine. We excluded from the analysis PLWHIV with no available pre-switch genotypic test or with a known resistance mutation to one of the study drugs. We evaluated incidence of virological failure (VF) and treatment discontinuation (TD), as well as changes in immunological and metabolic parameters.

RESULTS

We enrolled 592 PLWHIV: 306 in the lamivudine group and 286 in the rilpivirine group. We observed nine VFs in the lamivudine group [1.4 VF per 100 patient-years of follow-up (PYFU)] and four VFs in the rilpivirine group (0.6 VF per 100 PYFU). Subsequent genotypic analysis showed no acquired resistance-associated mutations in those experiencing VF. Estimated probability of maintaining virological suppression at 144 and 240 weeks were 96.6% and 92.7%, respectively, in the lamivudine group and 98.7% and 98.7%, respectively, in the rilpivirine group (log-rank P = 0.172). The estimated probability of maintaining study regimen at Week 240 was 82.3% in the lamivudine group and 85.9% in the rilpivirine group (log-rank P = 0.018). We observed a significant improvement in CD4+ cell count at Week 240 in the lamivudine group (P = 0.012); in the rilpivirine group we registered a significant increase in CD4/CD8 ratio (P = 0.014).

CONCLUSIONS

Both analysed strategies are effective and safe as switch strategies in clinical practice, with a low incidence of VF and a favourable immunological recovery, even in the long term.

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.

Virological efficacy of switch to DTG plus 3TC in a retrospective observational cohort of suppressed HIV-1 patients with or without past M184V: the LAMRES study

OBJECTIVES

The aim of this study was to assess the efficacy of dolutegravir plus lamivudine (DTG+3TC) in a large set of virologically suppressed HIV-1 infected individuals with or without past M184V mutation.

METHODS

This observational study included individuals who switched to DTG+3TC with ≥1 genotype before switch. Survival analysis was used to evaluate the role of past M184V on virological rebound (VR) or blips after DTG+3TC switch.

RESULTS

A total of 712 individuals followed in several clinical centres in France, Italy and Spain were analysed. Past M184V was present in 60 (8.4%) individuals. By 3 years after switch, the overall probability of VR and blips was 6.7% and 6.9%, respectively, without any statistical significance according to the presence/absence of past M184V. A significantly higher probability of VR was found in individuals harbouring M184V before DTG+3TC with a duration of virological suppression (Ts) ≤.3.5 years compared to others (M184V+Ts ≤.3.5 years: 22.7%; M184M+Ts ≤.3.5 years: 9.0%; M184V+Ts >3.5 years: 7.8%; M184M+Ts >3.5 years: 4.9%; P = 0.007). This finding was not confirmed in multivariable models adjusting for behavioural and demographic variables. Genotypic resistance test after VR under DTG+3TC was available for 8/39 individuals; one poorly adherent individual developed M184V. No resistance to INIs was found.

CONCLUSION

In this retrospective observational study, the probability of VR and blips in patients switching to DTG+3TC was very low after 3 years of treatment regardless M184V. The effect of a short duration of previous virological suppression in individuals with M184V remains troubling and needs ad hoc clinical trials to be confirmed.

Real-Life Impact of Drug Toxicity on Dolutegravir Tolerability: Clinical Practice Data from a Multicenter Italian Cohort

Dolutegravir (DTG) is currently one of the most used Integrase inhibitors (INI) in antiretroviral therapies (ARV) in both naïve and experienced people living with HIV (PLWHIV). We analyzed a multicenter cohort of PLWHIV, both naïve and experienced, starting an ARV including DTG. We enrolled 3775 PLWHIV: 2763 (73.2%) were males, with a median age of 50 years. During 9890.7 PYFU, we observed 930 discontinuations (9.4 per 100 PYFU). Estimated probabilities of maintaining DTG at three and five years were 75.1% and 67.2%, respectively. Treatment-naïve pts showed a lower probability of maintaining DTG at three and five years compared to treatment-experienced PLWHIV (log-rank p < 0.001). At a multivariate analysis, a longer time of virological suppression (aHR 0.994, p < 0.001) and having experienced a previous virological failure (aHR 0.788, p = 0.016) resulted protective against DTG discontinuation. Most discontinuations (84.0%) happened within the first 12 months of DTG initiation, in particular, 92.2% of discontinuations due to neuropsychiatric toxicity were observed in the first year. Our data confirm the overall good tolerability of DTG in clinical practice, with a low rate of discontinuations. CNS toxicity resulted the main reason for DTG discontinuation, with most related interruptions happening in the first year from DTG introduction.