Efficacy and Safety of Switching to Dolutegravir/Lamivudine Versus Continuing a Tenofovir Alafenamide-Based Regimen in Virologically Suppressed Adults With Human Immunodeficiency Virus Type 1: Subgroup Analysis of Participants With Elvitegravir as Baseline Third Agent From the TANGO Study.

TANGO results have established the durable efficacy of dolutegravir/lamivudine in virologically suppressed individuals who switched from 3- or 4-drug tenofovir alafenamide (TAF)-based regimens. In this post hoc subgroup analysis, 144-week efficacy and tolerability of dolutegravir/lamivudine in participants who switched from elvitegravir/cobicistat/emtricitabine/TAF were consistent with the overall switch population. Clinical Trials Registration: NCT03446573.

Efficacy and safety of switching to dolutegravir/lamivudine in virologically suppressed people with HIV-1 aged ≥ 50 years: week 48 pooled results from the TANGO and SALSA studies.

BACKGROUND: As the population of people with HIV ages, concerns over managing age-related comorbidities, polypharmacy, immune recovery, and drug-drug interactions while maintaining viral suppression have arisen. We present pooled TANGO and SALSA efficacy and safety results dichotomized by age (< 50 and ≥ 50 years). METHODS: Week 48 data from the open-label phase 3 TANGO and SALSA trials evaluating switch to once-daily dolutegravir/lamivudine (DTG/3TC) fixed-dose combination vs continuing current antiretroviral regimen (CAR) were pooled. Proportions of participants with HIV-1 RNA ≥ 50 and < 50 copies/mL (Snapshot, intention-to-treat exposed) and safety were analyzed by age category. Adjusted mean change from baseline in CD4 + cell count was assessed using mixed-models repeated-measures analysis. RESULTS: Of 1234 participants, 80% of whom were male, 29% were aged ≥ 50 years. Among those aged ≥ 50 years, 1/177 (< 1%) DTG/3TC participant and 3/187 (2%) CAR participants had HIV-1 RNA ≥ 50 copies/mL at 48 weeks; proportions with HIV-1 RNA < 50 copies/mL were high in both treatment groups (≥ 92%), consistent with overall efficacy and similar to observations in participants aged < 50 years (≥ 93%). Regardless of age category, CD4 + cell count increased or was maintained from baseline with DTG/3TC. Change from baseline in CD4 + /CD8 + ratio was similar across age groups and between treatment groups. One CAR participant aged < 50 years had confirmed virologic withdrawal, but no resistance was detected. In the DTG/3TC group, incidence of adverse events (AEs) was similar across age groups. Proportions of AEs leading to withdrawal were low and comparable between age groups. Although drug-related AEs were generally low, across age groups, drug-related AEs were more frequent in participants who switched to DTG/3TC compared with those who continued CAR. While few serious AEs were observed in both treatment groups, more were reported in participants aged ≥ 50 years vs < 50 years. CONCLUSIONS: Among individuals with HIV-1, switching to DTG/3TC maintained high rates of virologic suppression and demonstrated a favorable safety profile, including in those aged ≥ 50 years despite higher prevalence of concomitant medication use and comorbidities. TRIAL REGISTRATION NUMBER: TANGO, NCT03446573 (February 27, 2018); SALSA, NCT04021290 (July 16, 2019).

Dolutegravir + Lamivudine vs. Dolutegravir + Tenofovir Disoproxil Fumarate/Emtricitabine: Very-Low-Level HIV-1 Replication through 144 Weeks in the GEMINI-1 and GEMINI-2 Studies.

In GEMINI-1/-2, dolutegravir + lamivudine was non-inferior to dolutegravir + tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) in achieving viral suppression (viral load [VL] < 50 copies/mL) in treatment-naive adults. Abbott's RealTime HIV-1 assay provides quantitative VL (40-10,000,000 copies/mL) and qualitative target detected or target not detected (TND) for VL < 40 copies/mL. This post hoc analysis assessed very-low-level viremia and "blips" through Week 144. Proportions with VL < 40 copies/mL and TND are presented overall and by baseline VL and CD4+ cell count. "Blips" (single VL ≥ 50 to <200 copies/mL with adjacent values < 50 copies/mL) were assessed from Day 1 after VL suppression and from Weeks 48 through to 144. Proportions with TND increased through Week 48 and were similar between groups at all visits (Week 144: dolutegravir + lamivudine, 451/716 [63%]; dolutegravir + TDF/FTC, 465/717 [65%]). By observed analysis, TND rates were similar between groups across baseline subgroups. Through Week 144, proportions with ≥1 "blip" were generally comparable for dolutegravir + lamivudine vs. dolutegravir + TDF/FTC from Day 1 (15% vs. 20%) and from Week 48 (7% vs. 11%). Through 144 weeks, the proportions with TND or "blips" were similar between dolutegravir + lamivudine and the three-drug comparator, reinforcing the efficacy and durability of dolutegravir + lamivudine.

Durable Efficacy of Switching From a 3- or 4-Drug Tenofovir Alafenamide-Based Regimen to the 2-Drug Regimen Dolutegravir/Lamivudine in the TANGO Study Through Week 196.

BACKGROUND: Switching to the 2-drug regimen dolutegravir/lamivudine demonstrated durable non-inferior efficacy vs continuing 3- or 4-drug tenofovir alafenamide-based regimens for maintaining virologic suppression in people with HIV-1 through Week 144 in TANGO. SETTING: 134 centers, 10 countries. METHODS: Adults with HIV-1 RNA <50 copies/mL for >6 months and no history of virologic failure were randomized to switch from stable tenofovir alafenamide-based regimens to dolutegravir/lamivudine on Day 1 (early-switch group) for 196 weeks. Those randomized to continue tenofovir alafenamide-based regimens on Day 1 who maintained virologic suppression at Week 144 switched to dolutegravir/lamivudine at Week 148 (late-switch group). Efficacy, safety, and tolerability (including weight and biomarker changes) of dolutegravir/lamivudine in early-switch and late-switch groups were assessed through Week 196. RESULTS: Overall, 369 participants switched to dolutegravir/lamivudine on Day 1 (early-switch) and 298 switched at Week 148 (late-switch). In the early-switch group, 83% (306/369) maintained virologic suppression through Year 4, and 3% (11/369) reported new adverse events between Weeks 144 and 196. The late-switch group at Week 196 and early-switch group at Week 48 had comparable proportions with virologic suppression (93% each) and similar safety profiles. No late-switch participants and 1 early-switch participant met confirmed virologic withdrawal criteria through Week 196, with no resistance-associated mutations observed. Treatment continued to be well tolerated long-term. CONCLUSION: Switching from tenofovir alafenamide-based regimens to dolutegravir/lamivudine showed durable efficacy, high barrier to resistance, and good tolerability through 4 years. These results support dolutegravir/lamivudine as a robust treatment for maintaining virologic suppression.

Very-Low-Level Viremia, Inflammatory Biomarkers, and Associated Baseline Variables: Three-Year Results of the Randomized TANGO Study.

Background: We compared proportions of participants with target detected, target not detected (TND), and elevated viral load (VL) and assessed baseline variables associated with week 144 inflammatory biomarker levels between dolutegravir-lamivudine (DTG/3TC) and tenofovir alafenamide-based regimens (TBRs) in the TANGO study (post hoc). Methods: TANGO is an open-label, multicenter, phase 3 study that randomized adults with VL <50 copies/mL to switch to once-daily fixed-dose DTG/3TC or continue TBR. At baseline and each study visit, the VL was measured. Elevated VL event frequencies were assessed, including "blips." Interleukin 6, D-dimer, high-sensitivity C-reactive protein, soluble CD14, and soluble CD163 were measured at baseline and at week 144. Loge-transformed week 144 biomarker levels were compared between treatment groups using an analysis of covariance model adjusting for baseline variables. Results: High, comparable proportions of participants had VL <40 copies/mL and TND at week 144 (DTG/3TC, 279 of 369 [76%]; TBR, 267 of 372 [72%], intention-to-treat exposed Snapshot analysis; adjusted difference, 3.9% [95% confidence interval, -2.5% to 10.2%]), with similar TND proportions at all postbaseline visits (123 of 369 [33%] vs 101 of 372 [27%], respectively). Similar proportions of DTG/3TC participants had ≥1 postbaseline VL ≥50 copies/mL (28 of 369 [8%] vs 42 of 372 [11%] for TBR), primarily blips (18 of 369 [5%] and 26 of 372 [7%], respectively). Week 144 inflammatory biomarker levels were low and comparable between groups and associated with multiple demographic and baseline characteristics, including baseline biomarker levels, indicating a multifactorial inflammatory response. Conclusions: Week 144 biomarker levels were low and generally comparable between treatment groups, reflecting similar, robust, and durable viral suppression observed using the stringent TND end point. Trial registration:  ClinicalTrials.gov, NCT03446573.

Effects of the HIV-1 maturation inhibitor GSK3640254 on QT interval in healthy participants.

GSK3640254 (GSK'254) is a novel HIV-1 maturation inhibitor with pharmacokinetics supporting once-daily (QD) therapy for HIV-1 treatment. This thorough QT/corrected QT (QTc) study evaluated the effect of GSK'254 on cardiac repolarization. In this two-part, randomized study, healthy participants received GSK'254 or placebo QD for 7 days (part 1) to determine safety and pharmacokinetics of a 500-mg supratherapeutic dose. Four sequential treatment periods composed the main QTc study (part 2): GSK'254 100 mg, GSK'254 500 mg, placebo QD for 7 days, or placebo QD for 6 days with a 400-mg moxifloxacin dose on Day 7 (all with a moderate-fat meal). Concentration-QTc analyses modeled the relationship between GSK'254 plasma concentrations and placebo-adjusted change from baseline in QT interval corrected with Fridericia's formula (ΔΔQTcF). Of 50 participants enrolled, 48 completed the study (part 1, 8/8; part 2, 40/42). Least-squares (LS) mean change from baseline in QTcF for GSK'254 100 mg followed the placebo pattern across time points (maximum LS mean ΔΔQTcF, 1.7 ms); the upper bound of the 90% CI remained <10 ms. Maximum LS mean ΔΔQTcF for GSK'254 500 mg exceeded the 10-ms threshold: 10.6 ms (90% CI 7.75-13.38). Neither GSK'254 dose had clinically relevant effects on heart rate or cardiac conduction. By concentration-QTc analysis, no effect on ΔΔQTcF >10 ms is expected up to GSK'254 concentrations of ~3070 ng mL-1 . No clinically relevant effects on cardiac parameters were seen in healthy participants with GSK'254 at the 100-mg dose.

Cardiometabolic Parameters 3 Years After Switch to Dolutegravir/Lamivudine vs Maintenance of Tenofovir Alafenamide-Based Regimens.

Background: Cardiometabolic outcomes were investigated 3 years after switching to the 2-drug regimen dolutegravir/lamivudine (DTG/3TC) vs continuing 3-/4-drug tenofovir alafenamide (TAF)-based regimens in a multicenter phase 3 noninferiority study based on an open-label randomized design. Method: Adults with virologically suppressed HIV-1 switched to once-daily DTG/3TC (n = 369) or continued TAF-based regimens (n = 372). Cardiometabolic health parameters were assessed through week 144 via mixed-model repeated measures or logistic regression analyses, adjusting for baseline variables. Results: At week 144, 13% (42/316) of the DTG/3TC group and 12% (37/303) of the TAF-based regimen group had ≥10% weight gain from baseline (adjusted odds ratio, 1.11; 95% CI, .68-1.80). Adjusted change from baseline in serum leptin, a surrogate marker of adiposity, was similar between groups (treatment ratio, 1.00; 95% CI, .89-1.13). The lipid profile generally favored DTG/3TC in the baseline boosted subgroup. Adjusted odds revealed no clinically meaningful differences between groups: homeostatic model assessment of insulin resistance ≥2 (adjusted odds ratio, 0.79; 95% CI, .50-1.26), metabolic syndrome (International Diabetes Federation criteria, 0.99; .59-1.68), hepatic fibrosis (fibrosis-4 index score ≥1.45, 1.39; .63-3.06), and coronary artery disease risk (Framingham risk score ≥10%, 0.92; .56-1.49). Baseline variables and characteristics associated with odds of each cardiometabolic parameter outcome were consistent with known risk factors, including age, sex, race, and some disease characteristics. Conclusions: Cardiometabolic health 3 years after switching to DTG/3TC was comparable to that for individuals continuing TAF-based regimens, further supporting DTG/3TC as a robust switch option with a stable metabolic profile. Trial registration: ClinicalTrials.gov NCT03446573.

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.

Sustained Virologic Suppression With Dolutegravir/Lamivudine in a Test-and-Treat Setting Through 48 Weeks.

Background: We assessed the efficacy and safety of dolutegravir/lamivudine (DTG/3TC) in a US test-and-treat setting at a secondary 48-week time point of the multicenter, single-arm, phase IIIb STAT study. Methods: Participants were eligible adults newly diagnosed with human immunodeficiency virus (HIV)-1 and had started once-daily DTG/3TC within 14 days of diagnosis, before laboratory results were available. Antiretroviral therapy (ART) was modified if baseline testing indicated DTG or 3TC resistance, hepatitis B virus (HBV) coinfection, or creatinine clearance <30 mL/min per 1.73 m2, and these participants remained in the study. A proportion with HIV-1 ribonucleic acid (RNA) <50 copies/mL at Week 48 was calculated among all participants (intention-to-treat-exposed [ITT-E] missing = failure analysis) and those with available data (observed analysis). Results: At Week 48, 82% of all participants regardless of ART (107 of 131; ITT-E missing = failure) and 97% with available data (107 of 110; observed analysis) achieved HIV-1 RNA <50 copies/mL. High proportions of virologic response were seen overall, including in participants with high viral load (≥500 000 copies/mL; 89%) or low CD4+ cell count (<200 cells/mm3; 78%) at baseline. Ten participants had treatment modification (baseline HBV coinfection, n = 5; participant/proxy decision, n = 2; baseline M184V resistance mutation, adverse event [AE; rash], and pregnancy, n = 1 each) before Week 48. Two participants met confirmed virologic failure criteria. No treatment-emergent resistance was observed. Ten participants reported drug-related AEs (all grade 1-2); no serious drug-related AEs occurred. Conclusions: Results demonstrated high proportions of participants with sustained virologic suppression, no treatment-emergent resistance, and good safety over 48 weeks, supporting first-line use of DTG/3TC in a test-and-treat setting.

Pharmacokinetic and pharmacokinetic/pharmacodynamic characterization of the dolutegravir/rilpivirine two-drug regimen in SWORD-1/-2 phase 3 studies.

AIM: SWORD-1 and SWORD-2 phase 3 studies concluded that switching virologically suppressed participants with HIV-1 from their current three- or four-drug antiretroviral regimen (CAR) to the two-drug regimen of once-daily dolutegravir (DTG, 50 mg) and rilpivirine (RPV, 25 mg) was safe, well tolerated and noninferior for maintaining HIV-1 suppression at week 48 and highly efficacious to week 148. A secondary objective was to characterize drug exposure and exposure-efficacy/safety relationships. METHODS: Adults with plasma HIV-1 RNA <50 copies/mL were randomized to switch to once-daily DTG + RPV on day 1 or to continue CAR for 52 weeks before switching. Trough plasma concentrations (C0) of DTG and RPV, the proportion of participants with HIV-1 RNA <50 copies/mL and adverse events to week 100 were summarized and subjected to exposure-response analyses in the overall population, in the subset of participants who switched from CAR containing enzyme-inducing drugs and by age category (≥50 and <50 years). The relationship between C0avg (individual average C0 across visits) and efficacy/safety was investigated. RESULTS: Although week 2 DTG and RPV C0 were lower in participants switching from enzyme-inducing antiretroviral drugs, C0 and C0avg stayed above in vitro antiviral protein binding-adjusted IC90 and to week 100 with viral suppression >89%. DTG or RPV C0avg showed no relationship with virologic failures or safety. Participants ≥50 years had similar C0avg and safety response to younger participants. CONCLUSION: No clinically relevant relationship between DTG or RPV exposures and virologic or safety response was observed, confirming the DTG + RPV switch for participants as a safe and effective treatment.

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.

Brief Report: Evaluation of Inflammation and Atherogenesis Biomarkers Through 148 Weeks Postswitch to Dolutegravir and Rilpivirine in SWORD-1/SWORD-2.

BACKGROUND: Switching to the 2-drug regimen dolutegravir + rilpivirine demonstrated noninferiority vs continuing a 3-drug or 4-drug current antiretroviral regimen (CAR) at week 48 and maintained high levels of virologic suppression to week 148 in the SWORD studies. We report inflammation and atherogenesis biomarkers postswitch to dolutegravir + rilpivirine. SETTING: SWORD-1: 65 centers, 13 countries; SWORD-2: 60 centers, 11 countries. METHODS: Virologically suppressed adults were randomized to switch to dolutegravir + rilpivirine (early-switch group; n = 513) or continue CAR (n = 511). Participants continuing CAR switched to dolutegravir + rilpivirine at week 52 (late-switch group; n = 477). Biomarkers were evaluated from Baseline to week 48 for dolutegravir + rilpivirine and CAR and noncomparatively for dolutegravir + rilpivirine postswitch through 148 weeks (early-switch) and 96 weeks (late-switch). RESULTS: Through week 48, changes in biomarkers did not significantly differ between dolutegravir + rilpivirine and CAR groups, except for increases in soluble CD14 and decreases in fatty acid-binding protein-2, which favored dolutegravir + rilpivirine. For inflammation biomarkers through week 148, there was no marked change in C-reactive protein, inconsistent changes in soluble CD14 and interleukin-6, and increases in soluble CD163. For atherogenesis biomarkers through week 148, fatty acid-binding protein-2 and soluble vascular cell adhesion molecule-1 showed sustained reductions; D-dimer showed inconsistent increases between early-switch vs late-switch groups. CONCLUSIONS: No consistent pattern of change in biomarkers postswitch to dolutegravir + rilpivirine was observed through weeks 48 and 148 in SWORD-1/SWORD-2, suggesting no association of increased inflammation or atherogenesis with the 2-drug regimen while maintaining virologic suppression.

Efficacy and Safety of Switching to Dolutegravir/Lamivudine Versus Continuing a Tenofovir Alafenamide-Based 3- or 4-Drug Regimen for Maintenance of Virologic Suppression in Adults Living With Human Immunodeficiency Virus Type 1: Results Through Week 144 From the Phase 3, Noninferiority TANGO Randomized Trial.

BACKGROUND: Switching to dolutegravir/lamivudine (DTG/3TC) was noninferior to continuing tenofovir alafenamide (TAF)-based regimens for maintaining virologic suppression at week 48 of the TANGO study. Here we present week 144 outcomes (efficacy, safety, weight, and biomarkers). METHODS: TANGO is a randomized (1:1, stratified by baseline third agent class), open-label, noninferiority phase 3 study. Virologically suppressed (>6 months) adults with human immunodeficiency virus type 1 (HIV-1) switched to once-daily DTG/3TC or continued TAF-based regimens. RESULTS: A total of 741 participants received study treatment (DTG/3TC, n = 369; TAF-based regimen, n = 372). At week 144, the proportion of participants with an HIV-1 RNA level ≥50 copies/mL (primary end point, Snapshot; intention-to-treat-exposed population) after switching to DTG/3TC was 0.3% (1 of 369) versus 1.3% (5 of 372) for those continuing TAF-based regimens, demonstrating noninferiority (adjusted treatment difference, -1.1 [95% confidence interval, -2.4 to .2), with DTG/3TC favored in the per-protocol analysis (adjusted treatment difference, -1.1 [-2.3 to -.0]; P = .04). Few participants met confirmed virologic withdrawal criteria (none in the DTG/3TC and 3 in the TAF-based regimen group), with no resistance observed. Drug-related adverse events were more frequent with DTG/3TC (15%; leading to discontinuation in 4%) than TAF-based regimens (5%; leading to discontinuation in 1%) through week 144, but rates were comparable after week 48 (4%; leading to discontinuation in 1% in both groups). Changes from baseline in lipid values generally favored DTG/3TC; no clinical impact on renal function and comparable changes in inflammatory and bone biomarkers across groups were observed. CONCLUSIONS: Switching to DTG/3TC demonstrated noninferior and durable efficacy compared with continuing TAF-based regimens in treatment-experienced adults with HIV-1, with good safety and tolerability, and no resistance through 144 weeks.

Integrase Inhibitor Resistance Mechanisms and Structural Characteristics in Antiretroviral Therapy-Experienced, Integrase Inhibitor-Naive Adults with HIV-1 Infection Treated with Dolutegravir plus Two Nucleoside Reverse Transcriptase Inhibitors in the DAWNING Study.

At week 48 in the phase IIIb DAWNING study, the integrase strand transfer inhibitor (INSTI) dolutegravir plus 2 nucleoside reverse transcriptase inhibitors demonstrated superiority to ritonavir-boosted lopinavir in achieving virologic suppression in adults with HIV-1 who failed first-line therapy. Here, we report emergent HIV-1 drug resistance and mechanistic underpinnings among dolutegravir-treated adults in DAWNING. Population viral genotyping, phenotyping, and clonal analyses were performed on participants meeting confirmed virologic withdrawal (CVW) criteria on dolutegravir-containing regimens. Dolutegravir binding to and structural changes in HIV-1 integrase-DNA complexes with INSTI resistance-associated substitutions were evaluated. Of participants who received dolutegravir through week 48 plus an additional 110 weeks for this assessment, 6 met CVW criteria with treatment-emergent INSTI resistance-associated substitutions and 1 had R263R/K at baseline but not at CVW. All 7 achieved HIV-1 RNA levels of <400 copies/mL (5 achieved <50 copies/mL) before CVW. Treatment-emergent G118R was detected in 5 participants, occurring with ≥2 other integrase substitutions, including R263R/K, in 3 participants and without other integrase substitutions in 2 participants. G118R or R263K increased the rate of dolutegravir dissociation from integrase-DNA complexes versus wild-type but retained prolonged binding. Overall, among treatment-experienced adults who received dolutegravir in DAWNING, 6 of 314 participants developed treatment-emergent INSTI resistance-associated substitutions, with a change in in vitro dolutegravir resistance of >10-fold and reduced viral replication capacity versus baseline levels. This study demonstrates that the pathway to dolutegravir resistance is a challenging balance between HIV-1 phenotypic change and associated loss of viral fitness. (This study has been registered at ClinicalTrials.gov under identifier NCT02227238.).

Three-year durable efficacy of dolutegravir plus lamivudine in antiretroviral therapy - naive adults with HIV-1 infection.

OBJECTIVE: To assess efficacy and safety of dolutegravir (DTG) + lamivudine (3TC) vs. DTG + tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) in treatment-naive adults with HIV-1 in the prespecified 144-week secondary analyses of GEMINI-1 and GEMINI-2. DESIGN: Identical, multicenter, phase III, randomized, non-inferiority studies (double-blind through 96 weeks). METHODS: Participants with HIV-1 RNA ≤500 000 copies/ml and no major viral resistance mutations to nucleoside reverse transcriptase inhibitors, nonnucleoside reverse transcriptase inhibitors, or protease inhibitors were randomized 1:1 to once-daily DTG + 3TC or DTG + TDF/FTC. RESULTS: At week 144, DTG + 3TC (N = 716) was noninferior to DTG + TDF/FTC (N = 717) in proportion of participants achieving HIV-1 RNA <50 copies/ml (Snapshot algorithm) in the pooled analysis (82% vs. 84%, respectively; adjusted treatment difference [95% confidence interval (CI)], -1.8% [-5.8, 2.1]), GEMINI-1 (-3.6% [-9.4, 2.1]), and GEMINI-2 (0.0% [-5.3, 5.3]). Twelve DTG + 3TC participants and nine DTG + TDF/FTC participants met protocol-defined confirmed virologic withdrawal (CVW) criteria; none developed treatment-emergent resistance. One DTG + 3TC participant who did not meet CVW criteria developed M184V at week 132 and R263R/K at week 144, conferring a 1.8-fold change in susceptibility to DTG; non-adherence to therapy was reported. Significantly fewer drug-related adverse events occurred with DTG + 3TC vs. DTG + TDF/FTC (20% vs. 27%; relative risk [95% CI], 0.76 [0.63-0.92]). Renal and bone biomarker changes favored DTG + 3TC. CONCLUSIONS: Three-year durable efficacy, long-term tolerability, and high barrier to resistance support first-line use of DTG + 3TC for HIV-1 treatment (see Supplemental Digital Content 1, http://links.lww.com/QAD/C297; video abstract).

Impact of treatment adherence on efficacy of dolutegravir plus lamivudine and dolutegravir plus tenofovir disoproxil fumarate/emtricitabine: pooled analysis of the GEMINI-1 and GEMINI-2 clinical studies.

Background: GEMINI-1 and GEMINI-2 (ClinicalTrials.gov, NCT02831673 and NCT02831764, respectively) are double-blind, multicenter, phase III studies that demonstrated the non-inferiority of once-daily dolutegravir + lamivudine to dolutegravir + tenofovir disoproxil fumarate/emtricitabine in achieving HIV-1 RNA <50 copies/mL at 48, 96, and 144 weeks in treatment-naive adults with HIV-1 infection.Objective: We present a post hoc analysis of the impact of treatment adherence on Week 48 virologic response.Methods: Adherence was estimated using pill counts and categorized as ≥90% vs <90%. Unadjusted treatment differences with exact 95% CIs were derived for the proportion of participants with HIV-1 RNA <50 copies/mL within each adherence category, using Snapshot algorithm and last available on-treatment viral load through Week 48.Results: In each treatment group, 5% of participants had <90% adherence (dolutegravir + lamivudine group, 35/716; dolutegravir + tenofovir disoproxil fumarate/emtricitabine group, 34/717). The proportion of participants with HIV-1 RNA <50 copies/mL (Snapshot) at Week 48 in the <90% adherence group was 69% in the dolutegravir + lamivudine group and 65% in the dolutegravir + tenofovir disoproxil fumarate/emtricitabine group (analysis by last on-treatment viral load: 91% and 85%, respectively). Corresponding proportions in the ≥90% adherence group were 93% and 96% (analysis by last on-treatment viral load: 97% and 99%, respectively).Conclusions: Decreased adherence resulted in lower Week 48 virologic efficacy outcomes that were comparable between treatment groups. These results indicate that the robust antiviral activity and regimen forgiveness of dolutegravir + lamivudine is similar to dolutegravir-containing 3-drug regimens (see graphical abstract).

Pharmacokinetics, Safety, and Tolerability of a Single Oral Dose of Abacavir/Dolutegravir/Lamivudine Combination Tablets in Healthy Japanese Study Participants.

Pharmacokinetics, safety, and tolerability of abacavir 600 mg/dolutegravir 50 mg/lamivudine 300 mg were assessed in this phase 1, single-arm, open-label, single-dose study in fasted healthy male (n = 4) and female (n = 8) participants of Japanese heritage. Participants received a single dose of abacavir 600 mg/dolutegravir 50 mg/lamivudine 300 mg after an 8-hour fast, with safety assessments and blood samples for pharmacokinetic parameters collected through 72 hours after dosing. Geometric mean maximum plasma concentrations were 5.22 µg/mL (time to maximum concentration [tmax ], 1.01 hours) for abacavir, 4.13 µg/mL (tmax , 3.50 hours) for dolutegravir, and 3.35 µg/mL (tmax , 2.98 hours) for lamivudine. Geometric mean area under the concentration-time curve values were 18.20, 71.60, and 16.60 µg • h/mL for abacavir, dolutegravir, and lamivudine, respectively. No adverse events were reported, and no clinically significant findings were observed in laboratory values, physical examinations, or 12-lead electrocardiographic parameters. Single-tablet administration of abacavir 600 mg/dolutegravir 50 mg/lamivudine 300 mg was well tolerated in Japanese participants. Exposure to abacavir and lamivudine was comparable with that seen in previous studies. A modest increase in exposure to dolutegravir vs previous clinical studies was observed but is not expected to impact the clinical management of HIV-1 or increase the risk for adverse events.

Dolutegravir-based regimens in treatment-naive and treatment-experienced aging populations: analyses of 6 phase III clinical trials.

Background: Older adults living with HIV (OALWH) are a growing population facing unique challenges to successful antiretroviral therapy.Objective: To assess efficacy and safety profiles of antiretroviral regimens, including those containing dolutegravir, in OALWH.Methods: Combined data from 6 phase III/IIIb trials in treatment-naive (ARIA, FLAMINGO, SINGLE, SPRING-2; N = 2634) and treatment-experienced (DAWNING, SAILING; N = 1339) participants receiving dolutegravir- or non-dolutegravir-based regimens were analyzed by age (<50, ≥50 to <65, and ≥65 years). Baseline data included comorbidities and numbers of concomitant medications. Week 48 efficacy outcomes included virologic response (HIV-1 RNA <50 copies/mL) and CD4+ cell count change from baseline. Safety outcomes included incidence of adverse events (AEs), serious AEs, and AE-related withdrawals.Results: Use of ≥5 concomitant medications was more frequently reported among treatment-naive and treatment-experienced participants aged ≥50 to <65 (30% [90/296] and 25% [57/227], respectively) and ≥65 years (43% [10/23] and 29% [4/14]) than among those aged <50 years (13% [310/2315] and 11% [118/1098]). Comorbidities were more prevalent in the older age groups. For dolutegravir-based regimens, Week 48 rates of virologic response and change in CD4+ cell count were similar across age groups (treatment naive, 80-87% and 234-251 cells/mm3; treatment experienced, 70-100% and 105-156 cells/mm3, respectively). There were no major differences in safety outcomes in each age group.Conclusions: In these analyses of combined phase III/IIIb trial data, efficacy and safety of dolutegravir-based regimens were generally similar across age groups in treatment-naive or treatment-experienced participants. Polypharmacy and comorbidities were more common among OALWH than those aged <50 years.