Dolutegravir plus abacavir-lamivudine for the treatment of HIV-1 infection.

BACKGROUND: Dolutegravir (S/GSK1349572), a once-daily, unboosted integrase inhibitor, was recently approved in the United States for the treatment of human immunodeficiency virus type 1 (HIV-1) infection in combination with other antiretroviral agents. Dolutegravir, in combination with abacavir-lamivudine, may provide a simplified regimen. METHODS: We conducted a randomized, double-blind, phase 3 study involving adult participants who had not received previous therapy for HIV-1 infection and who had an HIV-1 RNA level of 1000 copies per milliliter or more. Participants were randomly assigned to dolutegravir at a dose of 50 mg plus abacavir-lamivudine once daily (DTG-ABC-3TC group) or combination therapy with efavirenz-tenofovir disoproxil fumarate (DF)-emtricitabine once daily (EFV-TDF-FTC group). The primary end point was the proportion of participants with an HIV-1 RNA level of less than 50 copies per milliliter at week 48. Secondary end points included the time to viral suppression, the change from baseline in CD4+ T-cell count, safety, and viral resistance. RESULTS: A total of 833 participants received at least one dose of study drug. At week 48, the proportion of participants with an HIV-1 RNA level of less than 50 copies per milliliter was significantly higher in the DTG-ABC-3TC group than in the EFV-TDF-FTC group (88% vs. 81%, P=0.003), thus meeting the criterion for superiority. The DTG-ABC-3TC group had a shorter median time to viral suppression than did the EFV-TDF-FTC group (28 vs. 84 days, P<0.001), as well as greater increases in CD4+ T-cell count (267 vs. 208 per cubic millimeter, P<0.001). The proportion of participants who discontinued therapy owing to adverse events was lower in the DTG-ABC-3TC group than in the EFV-TDF-FTC group (2% vs. 10%); rash and neuropsychiatric events (including abnormal dreams, anxiety, dizziness, and somnolence) were significantly more common in the EFV-TDF-FTC group, whereas insomnia was reported more frequently in the DTG-ABC-3TC group. No participants in the DTG-ABC-3TC group had detectable antiviral resistance; one tenofovir DF-associated mutation and four efavirenz-associated mutations were detected in participants with virologic failure in the EFV-TDF-FTC group. CONCLUSIONS: Dolutegravir plus abacavir-lamivudine had a better safety profile and was more effective through 48 weeks than the regimen with efavirenz-tenofovir DF-emtricitabine. (Funded by ViiV Healthcare; SINGLE ClinicalTrials.gov number, NCT01263015 .).

Missing CD4+ cell response in randomized clinical trials of maraviroc and dolutegravir.

BACKGROUND: Missing data can compromise inferences from clinical trials, yet the topic has received little attention in the clinical trial community. Shortcomings in commonly used methods used to analyze studies with missing data (complete case, last- or baseline-observation carried forward) have been highlighted in a recent Food and Drug Administration-sponsored report. This report recommends how to mitigate the issues associated with missing data. We present an example of the proposed concepts using data from recent clinical trials. METHODS: CD4+ cell count data from the previously reported SINGLE and MOTIVATE studies of dolutegravir and maraviroc were analyzed using a variety of statistical methods to explore the impact of missing data. Four methodologies were used: complete case analysis, simple imputation, mixed models for repeated measures, and multiple imputation. We compared the sensitivity of conclusions to the volume of missing data and to the assumptions underpinning each method. RESULTS: Rates of missing data were greater in the MOTIVATE studies (35%-68% premature withdrawal) than in SINGLE (12%-20%). The sensitivity of results to assumptions about missing data was related to volume of missing data. Estimates of treatment differences by various analysis methods ranged across a 61 cells/mm3 window in MOTIVATE and a 22 cells/mm3 window in SINGLE. CONCLUSIONS: Where missing data are anticipated, analyses require robust statistical and clinical debate of the necessary but unverifiable underlying statistical assumptions. Multiple imputation makes these assumptions transparent, can accommodate a broad range of scenarios, and is a natural analysis for clinical trials in HIV with missing data.

Oral bemnifosbuvir (AT-527) vs placebo in patients with mild-to-moderate COVID-19 in an outpatient setting (MORNINGSKY).

Aim: This phase III study assessed the efficacy/safety/antiviral activity/pharmacokinetics of bemnifosbuvir, a novel, oral nucleotide analog to treat COVID-19. Patients & methods: Outpatient adults/adolescents with mild-to-moderate COVID-19 were randomized 2:1 to bemnifosbuvir/placebo. Time to symptom alleviation/improvement (primary outcome), risk of hospitalization/death, viral load and safety were evaluated. Results: Although the study was discontinued prematurely and did not meet its primary end point, bemnifosbuvir treatment resulted in fewer hospitalizations (71% relative risk reduction), COVID-19-related medically attended hospital visits, and COVID-19-related complications compared with placebo. No reduction in viral load was observed. The proportion of patients with adverse events was similar; no deaths occurred. Conclusion: Bemnifosbuvir showed hospitalization reduction in patients with variable disease progression risk and was well tolerated. Clinical Trial Registration: NCT04889040 (ClinicalTrials.gov).

Dolutegravir/abacavir/lamivudine versus current ART in virally suppressed patients (STRIIVING): a 48-week, randomized, non-inferiority, open-label, Phase IIIb study.

BACKGROUND: Simplified dosing regimens are important for patients who face challenges in adhering to HIV-1 therapy. We investigated the safety and virological efficacy of switching to once-daily abacavir/dolutegravir/lamivudine (ABC/DTG/3TC). METHODS: The STRIIVING study was a randomized, open-label, Phase IIIb study in adults with HIV-1 RNA <50 copies/ml on antiretroviral therapy (ART) at enrolment (ClinicalTrials.gov identifier, NCT02105987). Subjects were randomly assigned to switch to ABC/DTG/3TC once daily for 48 weeks (early-switch group) or continue current ART for 24 weeks and then switch to ABC/DTG/3TC (late-switch group). The primary end point was the proportion of subjects with HIV-1 RNA <50 copies/ml at week 24. RESULTS: Of 553 subjects enrolled, 275 were randomly assigned to switch immediately to ABC/DTG/3TC and 278 continued on current ART. At week 24, 85% and 88% of subjects who switched to ABC/DTG/3TC or remained on current ART, respectively, were virologically suppressed, indicating that ABC/DTG/3TC was non-inferior (difference in proportion, -3.4%; 95% CI -9.1, 2.4). At week 48, 83% and 92% were virologically suppressed in the early- and late-switch groups, respectively. Adverse events were reported more frequently with ABC/DTG/3TC (66%) than with current ART (47%) by week 24, and in the late-switch group, 60% of subjects reported adverse events post-switch. Pharmacokinetic data supported immediate switch. HIV Treatment Satisfaction Questionnaire scores improved in participants switching to ABC/DTG/3TC versus current ART. CONCLUSIONS: Data demonstrating non-inferiority of switching to ABC/DTG/3TC versus continuing current ART support ABC/DTG/3TC as an option when considering switch regimens in HIV-1-infected adults with stable viral suppression.

Greater change in bone turnover markers for efavirenz/emtricitabine/tenofovir disoproxil fumarate versus dolutegravir + abacavir/lamivudine in antiretroviral therapy-naive adults over 144 weeks.

OBJECTIVE: Antiretroviral therapy initiation has been linked to bone mineral density and bone biomarker changes. We assessed long-term bone turnover biomarker effects over 144 weeks in patients initiating dolutegravir (DTG) + abacavir/lamivudine (ABC/3TC) versus efavirenz/emtricitabine/tenofovir disoproxil fumarate (EFV/FTC/TDF). METHODS: Patients randomized in SINGLE received DTG (50 mg once daily) + ABC/3TC or fixed-dose combination EFV/FTC/TDF. We evaluated vitamin D serum levels and bone turnover markers (BTMs), including type 1 collagen cross-linked C-telopeptide (CTx), osteocalcin, bone-specific alkaline phosphatase (BSAP), and procollagen type 1 N-terminal propeptide (P1NP), at baseline and weeks 48, 96, and 144. RESULTS: Among the 833 enrolled patients (68% white, 85% men), baseline median age was 35 years (range 18-85), median CD4 was 338 cells/µl, and median BMI was 24 kg/m. Fifty-three percent of patients smoked, and 6% reported baseline vitamin D use, with no meaningful differences between groups. Relative to baseline, CTx, osteocalcin, BSAP, and P1NP increased; vitamin D decreased in both groups at weeks 48, 96, and 144. Changes from baseline typically peaked at weeks 48 or 96 and for the four analytes, excluding vitamin D, with the EFV/FTC/TDF group having significantly greater changes from baseline at all time points. CONCLUSION: DTG + ABC/3TC in antiretroviral therapy-naive patients resulted in significantly lower increases in BTMs (CTx, osteocalcin, BSAP, P1NP) compared with EFV/FTC/TDF over 144 weeks. The observed changes are consistent with results from other smaller, randomized trials. These differences in BTMs likely correlate with changes in bone mineral density over time.

Dolutegravir efficacy at 48 weeks in key subgroups of treatment-naive HIV-infected individuals in three randomized trials.

OBJECTIVES: Dolutegravir (DTG) has been studied in three trials in HIV treatment-naive participants, showing noninferiority compared with raltegravir (RAL), and superiority compared with efavirenz and ritonavir-boosted darunavir. We explored factors that predicted treatment success, the consistency of observed treatment differences across subgroups and the impact of NRTI backbone on treatment outcome. DESIGN: Retrospective exploratory analyses of data from three large, randomized, international comparative trials: SPRING-2, SINGLE, and FLAMINGO. METHODS: We examined the efficacy of DTG in HIV-infected participants with respect to relevant demographic and HIV-1-related baseline characteristics using the primary efficacy endpoint from the studies (FDA snapshot) and secondary endpoints that examine specific elements of treatment response. Regression models were used to analyze pooled data from all three studies. RESULTS: Snapshot response was affected by age, hepatitis co-infection, HIV risk factor, baseline CD4⁺ cell count, and HIV-1 RNA and by third agent. Differences between DTG and other third agents were generally consistent across these subgroups. There was no evidence of a difference in snapshot response between abacavir/lamivudine (ABC/3TC) and tenofovir/emtricitabine (TDF/FTC) overall [ABC/3TC 86%, TDF/FTC 85%, difference 1.1%, confidence interval (CI) -1.8, 4.0 percentage points, P = 0.61] or at high viral loads (difference -2.5, 95% CI -8.9, 3.8 percentage points, P = 0.42). CONCLUSIONS: DTG is a once-daily, unboosted integrase inhibitor that is effective in combination with either ABC/3TC or TDF/FTC for first-line antiretroviral therapy in HIV-positive individuals with a variety of baseline characteristics.

Brief Report: Dolutegravir Plus Abacavir/Lamivudine for the Treatment of HIV-1 Infection in Antiretroviral Therapy-Naive Patients: Week 96 and Week 144 Results From the SINGLE Randomized Clinical Trial.

The SINGLE study was a randomized, double-blind, noninferiority study that evaluated the safety and efficacy of 50 mg dolutegravir + abacavir/lamivudine versus efavirenz/tenofovir/emtricitabine in 833 ART-naive HIV-1 + participants. Of 833 randomized participants, 71% in the dolutegravir + abacavir/lamivudine arm and 63% in the efavirenz/tenofovir/emtricitabine arm maintained viral loads of <50 copies per milliliter through W144 (P = 0.01). Superior efficacy was primarily driven by fewer discontinuations due to adverse events in the dolutegravir + abacavir/lamivudine arm [dolutegravir + abacavir/lamivudine arm, 16 (4%); efavirenz/tenofovir/emtricitabine arm, 58 (14%)] through W144 [corrected]. No treatment-emergent integrase or nucleoside resistance was observed in dolutegravir + abacavir/lamivudine recipients through W144.

96-Week results of abacavir/lamivudine versus tenofovir/emtricitabine, plus efavirenz, in antiretroviral-naive, HIV-1-infected adults: ASSERT study.

BACKGROUND: Abacavir/lamivudine (ABC/3TC) and tenofovir disoproxil fumarate/emtricitabine (TDF/FTC) are widely used as first-line antiretroviral therapies. However, there are limited data comparing the safety of these therapies with long-term use. The objective of this study was to assess the long-term safety of these commonly used first-line nucleoside/nucleotide combinations each administered with efavirenz (EFV). METHODS: This open-label, 96-week, randomized study compared the safety (renal, bone and metabolic) and efficacy of ABC/3TC and TDF/FTC plus EFV in HLA-B*5701-negative antiretroviral-naive adults. RESULTS: A total of 385 subjects were enrolled, and 249 (65%) subjects completed the study. The difference in changes from baseline in estimated glomerular filtration rate (calculated by the Modified Diet in Renal Disease equation) between treatment arms was not significant. There was a significant difference between the arms (P < 0.0001) for markers of tubular dysfunction (retinol-binding protein and ß-2 microglobulin) favouring ABC/3TC. Hip bone mineral density decreased from baseline in both arms, with a significantly greater decline with TDF/FTC (ABC/3TC -2.2% and TDF/FTC -3.5%; P < 0.001 at week 96). Subjects in the ABC/3TC arm had greater increases from baseline in median total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol and triglycerides. Adverse events were similar between arms. The virological failure rate was low in both arms. CONCLUSIONS: ABC/3TC and TDF/FTC in combination with EFV minimally affected estimated glomerular filtration rate over 96 weeks. TDF/FTC was associated with greater increases in tubular dysfunction and bone turnover marker levels, greater decreases in hip bone mineral density, and smaller increases in serum lipid levels.