Switch to bictegravir/emtricitabine/tenofovir alafenamide from dolutegravir-based therapy: 96-week pooled analysis.

OBJECTIVE: To evaluate the efficacy and safety of 96 weeks of bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) treatment in participants switching from dolutegravir (DTG)-based therapy. DESIGN: Studies 1489 (NCT02607930) and 1490 (NCT02607956) were phase 3 randomized, double-blind, active-controlled, first-line therapy trials in people with HIV-1. After 144 weeks of DTG-based or B/F/TAF treatment, participants could enter a 96-week open-label extension (OLE) of B/F/TAF. METHODS: A pooled analysis evaluated viral suppression (HIV-1 RNA <50 copies/mL) and changes in CD4+ cell count at OLE Weeks 48 and 96, treatment-emergent resistance, safety and tolerability after switch from a DTG-based regimen to B/F/TAF. Outcomes by prior treatment were summarized using descriptive statistics and compared by two-sided Wilcoxon rank sum test. RESULTS: At OLE Week 96, participants who switched to B/F/TAF (N=519) maintained high levels of virologic suppression (99.5% and 99.1% in those switching from DTG/abacavir/lamivudine and DTG+F/TAF, respectively) and CD4+ cell count, with no treatment-emergent resistance to B/F/TAF. Twenty-one participants experienced drug-related adverse events (AEs) after switching, with diarrhea, weight gain and headache occurring most commonly. There were no cases of proximal renal tubulopathy, drug-related Grade 4 AEs or serious AEs. Two participants discontinued B/F/TAF due to treatment-related AEs. Participants who switched from DTG/abacavir/lamivudine experienced statistically significant greater weight gain than those who switched from DTG+F/TAF; however, median weight change from the blinded phase baseline to OLE Week 96 was numerically similar across treatment groups. CONCLUSIONS: This medium-term analysis demonstrates the safety and efficacy of switching to B/F/TAF from a DTG-containing regimen in people with HIV-1.

Cohort profile: PRESTIGIO, an Italian prospective registry-based cohort of people with HIV-1 resistant to reverse transcriptase, protease and integrase inhibitors.

PURPOSE: The PRESTIGIO Registry was established in 2017 to collect clinical, virological and immunological monitoring data from people living with HIV (PLWH) with documented four-class drug resistance (4DR). Key research purposes include the evaluation of residual susceptibility to specific antiretrovirals and the validation of treatment and monitoring strategies in this population. PARTICIPANTS: The PRESTIGIO Registry collects annual plasma and peripheral blood mononuclear cell samples and demographic, clinical, virological, treatment and laboratory data from PLWH followed at 39 Italian clinical centres and characterised by intermediate-to-high genotypic resistance to ≥1 nucleoside reverse transcriptase inhibitors, ≥1 non-nucleoside reverse transcriptase inhibitors, ≥1 protease inhibitors, plus either intermediate-to-high genotypic resistance to ≥1 integrase strand transfer inhibitors (INSTIs) or history of virological failure to an INSTI-containing regimen. To date, 229 people have been recorded in the cohort. Most of the data are collected from the date of the first evidence of 4DR (baseline), with some prebaseline information obtained retrospectively. Samples are collected from the date of enrollment in the registry. FINDINGS TO DATE: The open-ended cohort has been used to assess (1) prognosis in terms of survival or development of AIDS-related or non-AIDS-related clinical events; (2) long-term efficacy and safety of different antiretroviral regimens and (3) virological and immunological factors predictive of clinical outcome and treatment efficacy, especially through analysis of plasma and cell samples. FUTURE PLANS: The registry can provide new knowledge on how to implement an integrated approach to study PLWH with documented resistance to the four main antiretroviral classes, a population with a limited number of individuals characterised by a high degree of frailty and complexity in therapeutic management. Given the scheduled annual updates of PLWH data, the researchers who collaborate in the registry can send study proposals at any time to the steering committee of the registry, which evaluates every 3 months whether the research studies can be conducted on data and biosamples from the registry and whether they are aimed at a better understanding of a specific health condition, the emergence of comorbidities or the effect of potential treatments or experimental drugs that may have an impact on disease progression and quality of life. Finally, the research studies should aim to be inclusive, innovative and in touch with the communities and society as a whole. TRIAL REGISTRATION NUMBER: NCT04098315.

Association between SARS-CoV-2 RNAemia, skewed T cell responses, inflammation, and severity in hospitalized COVID-19 people living with HIV.

Severe COVID-19 outcomes have been reported in people living with HIV (PLWH), yet the underlying pathogenetic factors are largely unknown. We therefore aimed to assess SARS-CoV-2 RNAemia and plasma cytokines in PLWH hospitalized for COVID-19 pneumonia, exploring associations with magnitude and functionality of SARS-CoV-2-specific immune responses. Eighteen unvaccinated PLWH (16/18 on cART; median CD4 T cell count 361.5/µL; HIV-RNA<50 cp/mL in 15/18) and 18 age/sex-matched people without HIV were consecutively recruited at a median time of 10 days from symptoms onset. PLWH showed greater SARS-CoV-2 RNAemia, a distinct plasma cytokine profile, and worse respiratory function (lower PaO2/FiO2nadir), all correlating with skewed T cell responses (higher perforin production by cytotoxic T cells as well as fewer and less polyfunctional SARS-CoV-2-specific T cells), despite preserved humoral immunity. In conclusion, these data suggest a link between HIV-related T cell dysfunction and poor control over SARS-CoV-2 replication/dissemination that may in turn influence COVID-19 severity in PLWH.

Optimizing the antiretroviral treatment focusing on long-term effectiveness and a person-centered approach. Consensus Guidance Using a Delphi Process.

Definitive data on the long-term success of the latest antiretroviral therapy (ART) strategies are still lacking. A panel of infectious diseases specialists was convened to develop a consensus on how to tailor and follow ART over time. Panelists used a Delphi technique to develop a list of statements describing preferred management approaches for ART and patient monitoring and quality of life evaluation. Ninety infectious diseases specialists from several Infectious Diseases Centers in Italy participated in the consensus process. A consensus was reached on virological and immunological parameters to use to monitor long-term efficacy of antiretroviral treatment, while there was no consensus on the use of specific inflammation and immune-activation markers in clinical routine. The panel agreed on the need for an antiretroviral treatment with the lowest impact on bone, kidney and cardiovascular toxicity and on the utility of quality-of-life monitoring during the standard follow up of people living with HIV. The consensus statements developed by a panel of infectious diseases specialists may provide guidance to practitioners for a person-centered approach aimed at obtaining long-term virological and clinical success for people living with HIV.

Characterization and outcomes of difficult-to-treat patients starting modern first-line ART regimens: Data from the ICONA cohort.

OBJECTIVES: Treatment failures to modern antiretroviral therapy (ART) raise concerns, as they could reduce future options. Evaluations of occurrence of multiple failures to modern ART are missing and their significance in the long run is unclear. METHODS: People with HIV (PWH) in the ICONA cohort who started a modern first-line ART were defined as 'difficult to treat' (DTT) if they experienced ≥1 among: i) ≥2 VF (2 viral loads, VL>200 copies/mL or 1 VL>1000 copies/mL) with or without ART change; ii) ≥2 treatment discontinuations (TD) due to toxicity/intolerance/failure; iii) ≥1 VF followed by ART change plus ≥1 TD due to toxicity/intolerance/failure. A subgroup of the DTT participants were matched to PWH that, after the same time, were non-DTT. Treatment response, analysing VF, TD, treatment failure, AIDS/death, and SNAE (Serious non-AIDS event)/death, were compared. Survival analysis by KM curves and Cox regression models were employed. RESULTS: Among 8061 PWH, 320 (4%) became DTT. Estimates of becoming DTT was 6.5% (95% CI: 5.8-7.4%) by 6 years. DTT PWH were significantly older, with a higher prevalence of AIDS and lower CD4+ at nadir than the non-DTT. In the prospective analysis, DTT demonstrated a higher unadjusted risk for all the outcomes. Once controlled for confounders, significant associations were confirmed for VF (aHR 2.23, 1.33-3.73), treatment failure (aHR 1.70, 1.03-2.78), and SNAE/death (aHR 2.79, 1.18-6.61). CONCLUSION: A total of 6.5% of PWH satisfied our definition of DTT by 6 years from ART starting. This appears to be a more fragile group who may have higher risk of failure.

Factors Associated with Low-Level Viremia in People Living with HIV in the Italian Antiviral Response Cohort Analysis Cohort: A Case-Control Study.

Despite effective antiretroviral therapies (ARTs), a subset of people living with HIV (PLWH) still experience low-level viremia (LLV, i.e., 50-1,000 copies/mL). The present study compared PLWH experiencing LLV with those maintaining virological suppression (VS) and explored the potential impact of preexisting drug resistance and other factors on LLV. We conducted a retrospective, 1:1 matched case-control study within a cohort of drug-experienced VS subjects from the Italian Antiviral Response Cohort Analysis database, followed in the period 2009-2019. Cases were individuals experiencing LLV, while controls were those who maintained VS. Matching was for calendar year of first ART regimen. Preexisting drug resistance was calculated as cumulative genotypic susceptibility score (GSS) according to regimen administered at the observational period start. To explore the effect of cumulative GSS, treated as a binary variable (≥2 and <2) and other factors on LLV, we performed a logistic regression analysis. Within a main population of 3,455 PLWH, 337 cases were selected. Cases were comparable to the controls for both gender and age. However, cases showed that they had experienced a longer time since HIV diagnosis, a higher number of drugs previously administered, lower baseline CD4+ T cell count and a higher zenith viral load (VL). By multivariate analysis, we found that higher zenith VL [adjusted odds ratio (aOR) (95% confidence interval [CI]) 1.30 (1.14-1.48)], a cumulative usage of both PI [aOR (95% CI): 2.03 (1.19-3.48)] and InSTI [aOR (95% CI): 2.23 (1.47-3.38)] and a cumulative GSS <2 [aOR (95% CI) 0.67 (0.46-0.98)], were associated with a higher risk in developing LLV. In current high-efficacy ART era, in drug-experienced PLWH, the predictors of increased risk of LLV were the presence of preexisting drug resistance, higher zenith VL, and previous PI, and InSTI exposure.

Pillars of long-term antiretroviral therapy success.

BACKGROUND: Meeting the challenge of antiretroviral therapy (ART) whose efficacy can last a lifetime requires continuous updating of the virological, pharmacological, and quality of life outcomes to be pursued and a continuous review of literature data on the efficacy and tolerability of new drugs and therapeutic strategies. METHODS: With the aim of identifying open questions and answers about the current controversies in modern ART, we adapted the Design Thinking methodology to the needs of the design phase of a scientific article, involving a team of experts in HIV care. RESULTS: Five main pillars of treatment success were discussed: sustained virologic suppression over time; immunological recovery; pharmacological attributes; long-term tolerability and safety of ART; and people's satisfaction and quality of life. The definition of the outcomes to be achieved in each thematic area and the tools to achieve them were reviewed and discussed. CONCLUSIONS: Long-term treatment success should be intended as a combination of HIV-RNA suppression, immune recovery, and high quality of life. To achieve this, the regimen should be well-tolerated, with high potency, genetic barrier, and forgiveness, and should be tailored by a person-centered perspective, based on individual needs, preferences, and therapeutic history.

Bictegravir/emtricitabine/tenofovir alafenamide as initial treatment for HIV-1: five-year follow-up from two randomized trials.

Background: Bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) is a single-tablet regimen recommended for HIV-1 treatment. The safety and efficacy of B/F/TAF as initial therapy was established in two Phase 3 studies: 1489 (vs dolutegravir [DTG]/abacavir/lamivudine) and 1490 (vs DTG + F/TAF). After 144 weeks of randomized follow-up, an open-label extension evaluated B/F/TAF to 240 weeks. Methods: Of 634 participants randomized to B/F/TAF, 519 completed the double-blinded treatment, and 506/634 (80%) chose the 96-week open-label B/F/TAF extension, which was completed by 444/506 (88%) participants. Efficacy was based on the secondary outcome of the proportion of participants with HIV-1 RNA <50 copies/mL at Week 240 by missing = excluded and missing = failure methods. All 634 participants who were randomized to B/F/TAF and received at least one dose of B/F/TAF were included in efficacy and safety analyses. (Study 1489: ClinicalTrials.govNCT02607930; EudraCT 2015-004024-54. Study 1490: ClinicalTrials.govNCT02607956; EudraCT 2015-003988-10). Findings: Of those with available virologic data, 98.6% (95% CI [97.0%-99.5%], 426/432) maintained HIV-1 RNA <50 copies/mL at Week 240 (missing = excluded); when missing virologic data were considered as failure, 67.2% (95% CI [63.4%-70.8%], 426/634) maintained HIV-1 RNA <50 copies/mL. Mean (SD) change in CD4+ count from baseline was +338 (236.2) cells/µL. No treatment-emergent resistance to B/F/TAF was detected. Adverse events led to drug discontinuation in 1.6% (n = 10/634) of participants (n = 5 with events considered drug-related). No discontinuations were due to renal adverse events. Median (IQR) total cholesterol increased 21 (1,42) mg/dL from baseline; the change in total cholesterol:HDL was 0.1 (-0.5,0.6). Median (IQR) weight change from baseline was +6.1 kg (2.0, 11.7) at Week 240. In Study 1489, hip and spine bone mineral density mean percent changes from baseline were ≤0.6%. Interpretation: Through 5 years of follow-up, B/F/TAF maintained high rates of virologic suppression with no treatment-emergent resistance and rare drug discontinuations due to adverse events. These results demonstrate the durability and safety of B/F/TAF in people with HIV. Funding: Gilead Sciences.

Healthcare Resource Consumption and Related Costs in Patients on Antiretroviral Therapies: Findings from Real-World Data in Italy.

This real-world analysis conducted on administrative databases of a sample of Italian healthcare entities was aimed at describing the role of therapeutic pathways and drug utilization in terms of adherence, persistence, and therapy discontinuation in HIV-infected patients under antiretroviral therapies (ART) and Tenofovir Alafenamide (TAF)-based regimens on healthcare resource consumption and related direct healthcare costs. Between 2015 and 2019, adults (≥18 years) prescribed with TAF-based therapies were identified and characterized in the year prior to the first prescription (index-date) for TAF-based therapies and followed-up until the end of data availability. Overall, 2658 ART-treated patients were included, 1198 of which were under a TAF-based regimen. TAF-based therapies were associated with elevated percentages of adherence (83.3% patients with proportion of days covered, PDC > 95% and 90.6% with PDC > 85%) and persistence (78.5%). The discontinuation rate was low in TAF-treated patients, ranging from 3.3% in TAF-switchers to 5% in naïve. Persistent patients had lower overall mean annual healthcare expenditures (EUR 11,106 in persistent vs. EUR 12,380 in non-persistent, p = 0.005), and this trend was statistically significant also for costs related to HIV hospitalizations. These findings suggest that a better therapeutic management of HIV infection might result in positive clinical and economic outcomes.

SARS-CoV-2 infection clinical picture and outcomes in adults living with HIV: a cohort analysis.

Existing evidence about HIV and SARS-CoV-2 co-infection has, so far, yield conflicting results. Methods: This is a cohort, single center, clinical study aimed at identifying possible characteristics of PLWH that could correlate with the risk of acquiring SARS-CoV-2 and would influence the outcome. 155 cases of SARS-CoV-2 infection were compared with 307 PLWH who tested negative. No variable was associated with an increased risk of infection. SARS-CoV-2 PLWH were completely asymptomatic in 20.6% of cases. Factors associated with severe COVID-19 were age (P=0.001), diabetes (P=0.009) hypertension (P=0.004), cardiovascular disease (P=0.001) or an increasing number of chronic co-morbidities (P=0.002); only the first two variables retained statistical significance in a multivariable model. Only older age and a lower CD4 count were statistically associated with death in the multivariate model. Sixteen PLWH not included in the analysis were infected by SARS-Cov-2 after vaccination. In 4 cases the infection was completely asymptomatic, while in the remaining 12 cases the infection was mild and resembled a flu-like syndrome. Conclusions: No baseline characteristic defines patients at greater risk of SARS-CoV-2 infection. Older age and the presence of multi-comorbidities are risk factors for a severe clinical course. Lower CD4 counts correlate with a fatal outcome.

Residual phenotypic susceptibility to doravirine in multidrug-resistant HIV-1 from subjects enrolled in the PRESTIGIO Registry.

OBJECTIVES: Doravirine shows a rather distinct resistance profile within the nonnucleoside reverse transcriptase inhibitor (NNRTI) class. This study aimed to evaluate the phenotypic susceptibility to doravirine, rilpivirine and etravirine in a panel of multidrug-resistant (MDR) HIV-1 isolates collected from people living with HIV (PLWH) enrolled in the PRESTIGIO Registry. METHODS: Recombinant viruses expressing PLWH-derived protease, reverse transcriptase coding regions were generated from plasma samples at virological failure with documented resistance to protease inhibitors, nucleoside reverse transcriptase inhibitors, NNRTIs and integrase strand transfer inhibitors. In vitro susceptibility was assessed through a phenotypic assay measuring fold-change values with respect to the reference NL4-3 virus. Genotypic susceptibility was computed by the Stanford HIVdb algorithm 8.9-1. RESULTS: Plasma samples were collected from 22 PLWH: 20 (91%) were male, median age 55 years (IQR 50-58), time since HIV-1 diagnosis 27 years (23-31) and time on antiretroviral treatment 23 years (22-26). Median doravirine, etravirine and rilpivirine fold-change values were 9.8 (2.9-40.4), 42.9 (3.1-100.0) and 100.0 (17.9-100.0), respectively. According to the fold-change cut-offs, full susceptibility was observed in five (23%), four (18%) and one (5%) cases with doravirine, etravirine and rilpivirine, respectively. Irrespective of the presence of specific doravirine mutations, higher numbers of NNRTI mutations correlated with higher fold-change values for doravirine. By comparing the distribution of fold-change values with the Stanford HIVdb predicted susceptibility, a significant correlation was detected for doravirine and rilpivirine but not etravirine. CONCLUSION: Despite extensive cross-resistance among NNRTIs, doravirine can be a valid option in a proportion of PLWH with MDR HIV-1. Doravirine activity appeared to be inferred with fair accuracy by the HIVdb algorithm.

Efficacy and Safety of Switching to the 2-Drug Regimen Dolutegravir/Lamivudine Versus Continuing a 3- or 4-Drug Regimen for Maintaining Virologic Suppression in Adults Living With Human Immunodeficiency Virus 1 (HIV-1): Week 48 Results From the Phase 3, Noninferiority SALSA Randomized Trial.

BACKGROUND: In TANGO, switching to dolutegravir/lamivudine (DTG/3TC) demonstrated long-term noninferior efficacy vs continuing tenofovir alafenamide-based regimens in treatment-experienced adults with HIV-1. The phase 3 SALSA study evaluated efficacy and safety of switching to DTG/3TC compared with continuing various 3-/4-drug current antiretroviral regimens (CARs). METHODS: Adults with HIV-1 RNA <50 copies/mL and no previous virologic failure were randomized (1:1, stratified by baseline third agent class) to switch to once-daily fixed-dose combination DTG/3TC or continue CAR (primary endpoint: proportion of participants with HIV-1 RNA ≥50 copies/mL at week 48; Snapshot, intention-to-treat-exposed population, 5% noninferiority margin). RESULTS: Overall, 493 adults (39% women; 39% aged ≥50 years; 19% African American/African heritage; 14% Asian) were randomized to switch to DTG/3TC (n = 246) or continue CAR (n = 247). At week 48, 1 (0.4%) participant in the DTG/3TC group and 3 (1.2%) in the CAR group had HIV-1 RNA ≥50 copies/mL (Snapshot), demonstrating noninferiority (adjusted difference, -0.8%; 95% CI, -2.4%, .8%). Zero participants met confirmed virologic withdrawal criteria; therefore, no resistance testing was performed. Drug-related adverse events were more frequent with DTG/3TC (20%) than CAR (6%) through week 48 but comparable post-week 24 (5% vs 2%, respectively). Proximal tubular renal function and bone turnover biomarkers improved with DTG/3TC. Both groups had generally minimal changes in lipids and inflammatory biomarkers. CONCLUSIONS: Switching to DTG/3TC was noninferior to continuing CAR for maintaining virologic suppression at week 48 with no observed resistance, supporting the efficacy, good safety, and high barrier to resistance of DTG/3TC. CLINICAL TRIALS REGISTRATION: www.clinicaltrials.gov, NCT04021290.

Bictegravir/emtricitabine/tenofovir alafenamide in older individuals with HIV: Results of a 96-week, phase 3b, open-label, switch trial in virologically suppressed people ≥65 years of age.

OBJECTIVES: Bictegravir/emtricitabine/tenofovir alafenamide (B/F/TAF) is an effective treatment for HIV-1 infection; however, clinical trial data in older people living with HIV (PLWH) are lacking. The primary 24-week and secondary 48-week analyses of study GS-US-380-4449 (NCT03405935), which assessed the efficacy and safety of switching to B/F/TAF in older PLWH, have been published. Here we report the results of the final 96-week analyses from the study. METHODS: In this 96-week, phase 3b, open-label, single-arm trial, virologically suppressed PLWH aged ≥65 years switched from elvitegravir/cobicistat/emtricitabine/tenofovir alafenamide or a tenofovir disoproxil fumarate-based regimen to B/F/TAF. Viral suppression, resistance, immune response, safety, tolerability and adherence were evaluated through week 96. RESULTS: Of 90 participants screened, 86 were enrolled and switched to B/F/TAF. No participants had HIV-1 RNA ≥50 copies/ml (by FDA Snapshot algorithm) at weeks 72 or 96; virologic suppression rates were 94.2% (81/86; 95% CI 87.0-98.1) and 74.4% (64/86; 95% CI 63.9-83.2), respectively. No treatment-emergent resistance was observed, and CD4 counts remained stable. There were no study drug-related serious adverse events. Three participants experienced drug-related treatment-emergent adverse events that led to premature drug discontinuation. There were no clinically relevant changes from baseline to week 96 in fasting lipid parameters, and the median change in body weight at week 96 was 0.0 kg (IQR -2.3, 2.0). Median self-reported adherence was 100% (IQR 100-100%). CONCLUSIONS: Switching to B/F/TAF is an effective long-term option for virologically suppressed adults ≥65 years of age, with favourable safety and tolerability profiles in this population.

Real world efficacy of dolutegravir plus lamivudine in people living with HIV with undetectable viral load after previous failures.

BACKGROUND: Dolutegravir (DTG) +lamivudine (3TC) combination has been found to be as effective as triple therapies, and has been extensively prescribed in clinical practice as a maintenance therapy. We aimed to investigate the effect of previous virological failures (VFs) on virological efficacy. METHODS: The analysis included data of people living with HIV (PLWH) with HIV-RNA ≤50 copies/mL enrolled in an Italian retrospective multicohort study who were switching to DTG+3TC. Primary endpoint was viral rebound (VR; confirmed HIV-RNA ≥50 copies/mL or single HIV-RNA ≥50 copies/mL followed by change of antiretroviral therapies [ART]). Kaplan-Meier curves were used to estimate probabilities of VR based upon histories of previous VFs (single HIV-RNA ≥1000 copies/mL or confirmed HIV-RNA ≥50 copies/mL). A weighted Cox regression model was fitted to estimate the causal hazard ratio (HR) of history of failure on the risk of VR. RESULTS: A total of 966 PLWH were included; 20.1% had a history of previous VF. VR was detected in 23 PLWH. The one-year probability was 1.2% (95% confidence interval [CI], 0.2%-2.2%) in PLWH without previous VF and 3.3% (95% CI, 0.4%-6.2%) in those with ≥1 VF (log-rank P = 0.042). By multivariate analysis adjusted for CD4+ cell count at nadir, duration of virological suppression, and mode of HIV transmission, PLWH with ≥1 previous VF had a higher risk of virological rebound than those without previous VF (adjusted hazard ratio 3.06 [95% CI, 1.00-9.44], P = 0.051). CONCLUSION: Despite the low absolute one-year risk in both groups, real-world data confirmed that PLWH with a previous failure have an increased risk of viral rebound.

Real World Data on Forgiveness to Uncomplete Adherence to Bictegravir/ Emtricitabine/Tenofovir Alafenamide.

Background: forgiveness is the ability of a given regimen to maintain complete viral suppression despite a documented imperfect adherence. We explored forgiveness of bictegravir/emtricitabine/tenofovir alafenamide. Methods: drug refills were used to calculate the percent day covered (PDC) as a proxy of adherence. Forgiveness was calculated as the achieved rate of a selected HIV-RNA threshold by a given level of imperfect adherence. Results: 281 adult PLWH were followed for 343 patient/years. Adherence was very high with a median of 98% (IQR 95-100%). A PDC as low as 70% was sufficient to obtain 100% and maintain virologic suppression. According to probit analysis adherence was not related to the possibility to maintain an HIV-RNA TND or < 50 copies/ml. Conclusions: Long-term success of ART needs effective regimens that are the least intrusive of the patient's lifestyle, an elevated forgiveness may be considered as an additional feature that can further improve long-term outcomes.

Long-term outcome of lamivudine/dolutegravir dual therapy in HIV-infected, virologically suppressed patients.

BACKGROUND: The use of DTG-containing two-drug regimens is one of the most promising solutions to the need to ease the management of HIV treatment without harming its efficacy and safety. We report long- term results in patients switched, while virologically suppressed, to the combination of dolutegravir (DTG) plus lamivudine (3TC). METHODS: This is a prospective, clinical, uncontrolled cohort enrolling ART-experienced people living with HIV (PLWH) with HIV-RNA < 50 copies/ml for 6 months or longer, negative hepatitis B virus surface antigen, and without known M184V/I mutations. Kaplan-Meiers curves are used to describe persistency of virological suppression on therapy and a Cox regression model to evaluate baseline characteristics and the risk of stopping therapy. RESULTS: 218 individuals switched their regimen since 2015. The mean estimated follow-up was of 64.3 months (95% CI 61.3-67.3) for approximately 1000 patient/years. After 5 years of follow-up, 77.1% were still on the DTG-3TC combination. No virologic failure was detected throughout the whole study period, and only 15 subjects presented single isolated viral blips above 50 copies/ml. Most patients stopped therapy because of reasons unrelated to study drugs (lost to follow-up; patients' decision; moved to other Centers), but due to the unselected nature of the casuistry; 11 subjects died in the 5 years of follow-up mostly because of pre-existing co-morbidities (6 neoplastic diseases and 2 end-stage liver disease). The median baseline CD4 count was 669 cells/mcl (IQR 483-927). After 5 years it raised to 899 cells/mcl (IQR 646-1160) (P < 0.001) without a significant change of CD8 counts that lowered from 767 cells/mcl (IQR 532-1034) to 683 cells/mcl (IQR 538-988). Consequently, the CD4/CD8 ratio varied from 0.93 (IQR 0.60-1.30) to 1.15 (IQR 0.77-1.45) (P < 0.0001). A non-significant (P = 0.320) increment of mean creatinine, 0.06 mg/dl in magnitude, was observed over the whole follow-up. CONCLUSION: These long-term results over 5 years reinforce the durability and good tolerability of DTG-3TC. Our results continue to support the recommended switch use of this 2DR as a well-accepted treatment option for ART-experienced PLWH.

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

Despite the wide use of single-tablet regimens (STRs), few real-life data are available regarding the impact of pre-existent drug resistance on virological failure (VF). We aimed to fill this gap by analysing 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, comprising 678 treatment-naïve (G1), 2309 treatment-experienced aviraemic (G2) and 929 viraemic (G3), of whom 65.2% were treated with a STR based on efavirenz (35.2%) or rilpivirine (30.0%). At 2 years after starting a 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) both in G2 and G3. A higher probability of VF was also found in the 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 appears to influence virological efficacy of STRs in treatment-experienced individuals (both aviraemic and viraemic).

Adherence to and Forgiveness of 3TC/DTG in a Real-World Cohort.

Background: adherence and forgiveness are key factors for virologic success. We evaluated them for 3TC/DTG. Methods: pharmacy refills were used to calculate the proportion of days covered (PDC). Forgiveness was calculated as the achieved rate of HIV-RNA threshold by a given level of imperfect adherence. Results: 240 PLWH were included. The median follow-up was 819 days (IQR 450-1459) for a total of 681 person/years of follow-up. Adherence was very high with a median of 99% (IQR 95%-100%). Consequently, the virologic response was sustained with 83.8% of PLWH never exceeding a HIV RNA of 50 copies/ml and 95.8% of subjects with a steadily HIV-RNA < 200 copies/ml. A PDC lower than 80% was associated with a negative outcome irrespective of the HIV-RNA threshold considered. Conclusions: The extensive virologic efficacy of 3TC/DTG demonstrated both in clinical trials and real-world experiences seems to rely more on its friendliness than on its forgiveness.

Correlates of Treatment and Disease Burden in People Living with HIV (PLHIV) in Italy.

Treatment burden is a multidimensional concept, including several aspects of life of patients affected by chronic conditions. It has been poorly explored in people living with HIV (PLHIV). An online anonymous survey of PLHIV taking antiretroviral therapy (ART) was conducted, in order to investigate the self-reported correlates of disease burden. HIV Treatment and Diseases Burden (TDB) was investigated with a questionnaire containing 31 items in 7 domains. Respondents were stratified in high burden (H-TDB)/low burden (L-TDB) according to overall HIV TDB mean + 1 standard deviation. Factors associated with H-TDB has been evaluated with a logistic regression model. In total, 531 PLHIV completed the questionnaire. 99 PLHIV had a H-TDB (18.6%). PLHIV with H-TDB were younger (p < 0.001), less frequently on current two drug antiretroviral (ARV) regimens (p = 0.01) and more frequently with plasma HIV-RNA >50 copies/mL (p = 0.04). At multivariable regression analysis, younger age (aOR 1.43, 95%CI 1.14-1.80; p = 0.002), not fully treatment satisfaction (aOR 2.19, 95%CI 1.28-3.74; p = 0.004), the need of a more accurate dialogue with treating physician (aOR 2.29, 95%CI 1.21-4.36, p = 0.01) and a self-declared lower overall Health Status (aOR 1.75, 95%CI 1.33-2.32; p = 0.002) were all associated with a H-TDB. One out of five PLHIV showed a high level of treatment and disease burden. Younger age, not fully satisfaction with ART and need of interaction with a tailored health system should be taken into consideration as correlates of treatment and disease burden in a patient-centered approach, to reduce the negative impact that it can produce on the overall perceived health status of the person.

Durability of rilpivirine-based versus integrase inhibitor-based regimens in a large cohort of naïve HIV-infected patients starting antiretroviral therapy.

OBJECTIVES: Comparisons between rilpivirine (RPV) and integrase strand transfer inhibitors (INSTIs) in antiretroviral therapy (ART)-naïve HIV-infected individuals are currently lacking. This study aimed to compare, in an observational cohort setting, the durability of treatment with RPV-based and INSTI-based first-line regimens. METHODS: Patients who started first-line ARTs based on RPV or INSTIs, with HIV-RNA < 100 000 copies/mL and CD4 cell count > 200 cells/µL were included. The primary endpoint was the cumulative probability of treatment failure (TF = virological failure [confirmed HIV-RNA > 50 copies/mL] or discontinuation of the anchor drug in the regimen), as assessed by the Kaplan-Meier method. A multivariable Cox regression was used to control for potential confounding. RESULTS: Of the 1991 included patients, 986 started ART with an RPV-based regimen and 1005 with an INSTIs-based regimen. The median (IQR) follow-up was 20 (10, 35) months. The cumulative 2-year probability of TF with RPV (9.1% [95% 7.2, 11.1]) was lower than that observed in the INSTIs group (16.6% [13.8, 19.4], P = 0.0002) but not when compared with dolutegravir (DTG) alone. Starting ART with an INSTIs-based regimen vs. RPV was associated with a higher risk of TF after controlling for potential confounding factors (adjusted hazard ratio, AHR [95% CI]: 1.64 [1.28, 2.10]; P < 0.001). The results were similar when restricting the analysis to single-tablet regimens, although the probability of virological success was higher for INSTIs and DTG. CONCLUSIONS: In ART-naïve patients with low viral loads and high CD4 counts, the risk of treatment failure was lower in those who started RPV-based vs. INSTIs-based regimens other than DTG-based ones.