Once-daily dolutegravir versus raltegravir in antiretroviral-naive adults with HIV-1 infection: 48 week results from the randomised, double-blind, non-inferiority SPRING-2 study.

BACKGROUND: Dolutegravir (S/GSK1349572) is a once-daily HIV integrase inhibitor with potent antiviral activity and a favourable safety profile. We compared dolutegravir with HIV integrase inhibitor raltegravir, as initial treatment for adults with HIV-1. METHODS: SPRING-2 is a 96 week, phase 3, randomised, double-blind, active-controlled, non-inferiority study that began on Oct 19, 2010, at 100 sites in Canada, USA, Australia, and Europe. Treatment-naive adults (aged ≥ 18 years) with HIV-1 infection and HIV-1 RNA concentrations of 1000 copies per mL or greater were randomly assigned (1:1) via a computer-generated randomisation sequence to receive either dolutegravir (50 mg once daily) or raltegravir (400 mg twice daily). Study drugs were given with coformulated tenofovir/emtricitabine or abacavir/lamivudine. Randomisation was stratified by screening HIV-1 RNA (≤ 100,000 copies per mL or >100,000 copies per mL) and nucleoside reverse transcriptase inhibitor backbone. Investigators were not masked to HIV-1 RNA results before randomisation. The primary endpoint was the proportion of participants with HIV-1 RNA less than 50 copies per mL at 48 weeks, with a 10% non-inferiority margin. Main secondary endpoints were changes from baseline in CD4 cell counts, incidence and severity of adverse events, changes in laboratory parameters, and genotypic or phenotypic evidence of resistance. Our primary analysis was by intention to treat. This trial is registered with ClinicalTrials.gov, number NCT01227824. FINDINGS: 411 patients were randomly allocated to receive dolutegravir and 411 to receive raltegravir and received at least one dose of study drug. At 48 weeks, 361 (88%) patients in the dolutegravir group achieved an HIV-1 RNA value of less than 50 copies per mL compared with 351 (85%) in the raltegravir group (adjusted difference 2·5%; 95% CI -2·2 to 7·1). Adverse events were similar between treatment groups. The most common events were nausea (59 [14%] patients in the dolutegravir group vs 53 [13%] in the raltegravir group), headache (51 [12%] vs 48 [12%]), nasopharyngitis (46 [11%] vs 48 [12%]), and diarrhoea (47 [11%] in each group). Few patients had drug-related serious adverse events (three [<1%] vs five [1%]), and few had adverse events leading to discontinuation (ten [2%] vs seven [2%] in each group). CD4 cell counts increased from baseline to week 48 in both treatment groups by a median of 230 cells per µL. Rates of graded laboratory toxic effects were similar. We noted no evidence of treatment-emergent resistance in patients with virological failure on dolutegravir, whereas of the patients with virologic failure who received raltegravir, one (6%) had integrase treatment-emergent resistance and four (21%) had nucleoside reverse transcriptase inhibitors treatment-emergent resistance. INTERPRETATION: The non-inferior efficacy and similar safety profile of dolutegravir compared with raltegravir means that if approved, combination treatment with once-daily dolutegravir and fixed-dose nucleoside reverse transcriptase inhibitors would be an effective new option for treatment of HIV-1 in treatment-naive patients. FUNDING: ViiV Healthcare.

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.

Dolutegravir in antiretroviral-naive adults with HIV-1: 96-week results from a randomized dose-ranging study.

OBJECTIVE: To evaluate the efficacy and safety/tolerability of dolutegravir (DTG, S/GSK1349572), a potent inhibitor of HIV integrase, through the full 96 weeks of the SPRING-1 study. DESIGN: ING112276 (SPRING-1) was a 96-week, randomized, partially blinded, phase IIb dose-ranging study. METHODS: Treatment-naive adults with HIV received DTG 10, 25, or 50 mg once daily or efavirenz (EFV) 600 mg once daily (control arm) combined with investigator-selected dual nucleos(t)ide reverse transcriptase inhibitor backbone regimen (tenofovir/emtricitabine or abacavir/lamivudine). The primary endpoint of the study was the proportion of participants with plasma HIV-1 RNA less than 50 copies/ml, based on time to loss of virologic response at 16 weeks (conducted for the purpose of phase III dose selection), with a planned analysis at 96 weeks. Safety and tolerability were also assessed. RESULTS: Of 208 participants randomized to treatment, 205 received study drug. At week 96, the proportion of participants achieving plasma HIV-1 RNA less than 50 copies/ml was 79, 78, and 88% for DTG 10, 25, and 50 mg, respectively, compared with 72% for EFV. The median increase from baseline in CD4 cells was 338 cells/µl with DTG (all treatment groups combined) compared with 301 cells/µl with EFV (P  = 0.155). No clinically significant dose-related trends in adverse events were observed, and fewer participants who received DTG withdrew because of adverse events (3%) compared with EFV (10%). CONCLUSION: Throughout the 96 weeks of the SPRING-1 study, DTG demonstrated sustained efficacy and favorable safety/tolerability in treatment-naive individuals with HIV-1.

Once-daily dolutegravir versus twice-daily raltegravir in antiretroviral-naive adults with HIV-1 infection (SPRING-2 study): 96 week results from a randomised, double-blind, non-inferiority trial.

BACKGROUND: In the primary analysis of SPRING-2 at week 48, dolutegravir showed non-inferior efficacy to and similar tolerability to raltegravir in adults infected with HIV-1 and naive for antiretroviral treatment. We present the 96 week results. METHODS: SPRING-2 is an ongoing phase 3, randomised, double-blind, active-controlled, non-inferiority study in treatment-naive adults infected with HIV-1 that started in Oct 19, 2010. We present results for the safety cutoff date of Jan 30, 2013. Patients had to be aged 18 years or older and have HIV-1 RNA concentrations of 1000 copies per mL or more. Patients were randomly assigned (1:1) to receive either dolutegravir (50 mg once daily) or raltegravir (400 mg twice daily), plus investigator-selected tenofovir-emtricitabine or abacavir-lamivudine. Prespecified 96 week secondary endpoints included proportion of patients with HIV-1 RNA less than 50 copies per mL, CD4 cell count changes from baseline, safety, tolerability, and genotypic or phenotypic resistance. We used an intention-to-treat exposed population (received at least one dose of study drug) for the analyses. Sponsor staff were masked to treatment assignment until primary analysis at week 48; investigators, site staff, and patients were masked until week 96. FINDINGS: Of 1035 patients screened, 827 were randomly assigned to study group, and 822 received at least one dose of the study drug (411 patients in each group). At week 96, 332 (81%) of 411 patients in the dolutegravir group and 314 (76%) of 411 patients in the raltegravir group had HIV-1 RNA less than 50 copies per mL (adjusted difference 4∙5%, 95% CI -1∙1% to 10∙0%) confirming non-inferiority. Secondary analyses of efficacy such as per protocol (HIV RNA <50 copies per mL: 83% for dolutegravir and 80% for raltegravir) and treatment-related discontinuation equals failure (93% without failure for dolutegravir; 91% for raltegravir) supported non-inferiority. Virological non-response occurred less frequently in the dolutegravir group (22 [5%] patients for dolutegravir vs 43 [10%] patients for raltegravir). Median increases in CD4 cell count from baseline were similar between groups (276 cells per µL for dolutegravir and 264 cells per µL for raltegravir). Ten patients (2%) in each group discontinued because of adverse events, with few such events between weeks 48 and 96 (zero in the dolutegravir group and one in the raltegravir group). No study-related serious adverse events occurred between week 48 and week 96. At virological failure, no additional resistance to integrase inhibitors or nucleotide reverse transcriptase inhibitors was detected since week 48 or in any patient receiving dolutegravir. INTERPRETATION: At week 96, once-daily dolutegravir was non-inferior to twice-daily raltegravir in treatment-naive, patients with HIV-1. Once-daily dosing without requirement for a pharmacokinetic booster makes dolutegravir-based therapy an attractive treatment option for HIV-1-infected treatment-naive patients.

Once daily dolutegravir (S/GSK1349572) in combination therapy in antiretroviral-naive adults with HIV: planned interim 48 week results from SPRING-1, a dose-ranging, randomised, phase 2b trial.

BACKGROUND: Dolutegravir (S/GSK1349572) is a new HIV-1 integrase inhibitor that has antiviral activity with once daily, unboosted dosing. SPRING-1 is an ongoing study designed to select a dose for phase 3 assessment. We present data from preplanned primary and interim analyses. METHODS: In a phase 2b, multicentre, dose-ranging study, treatment-naive adults were randomly assigned (1:1:1:1) to receive 10 mg, 25 mg, or 50 mg dolutegravir or 600 mg efavirenz. Dose but not drug allocation was masked. Randomisation was by a central integrated voice-response system according to a computer-generated code. Study drugs were given with either tenofovir plus emtricitabine or abacavir plus lamivudine. Our study was done at 34 sites in France, Germany, Italy, Russia, Spain, and the USA beginning on July 9, 2009. Eligible participants were seropositive for HIV-1, aged 18 years or older, and had plasma HIV RNA viral loads of at least 1000 copies per mL and CD4 counts of at least 200 cells per µL. Our primary endpoint was the proportion of participants with viral load of less than 50 copies per mL at week 16 and we present data to week 48. Analyses were done on the basis of allocation group and included all participants who received at least one dose of study drug. This study is registered with ClinicalTrials.gov, number NCT00951015. FINDINGS: 205 patients were randomly allocated and received at least one dose of study drug: 53, 51, and 51 to receive 10 mg, 25 mg, and 50 mg dolutegravir, respectively, and 50 to receive efavirenz. Week 16 response rates to viral loads of at most 50 copies per mL were 93% (144 of 155 participants) for all doses of dolutegravir (with little difference between dose groups) and 60% (30 of 50) for efavirenz; week 48 response rates were 87% (139 of 155) for all doses of dolutegravir and 82% (41 of 50) for efavirenz. Response rates between nucleoside reverse transcriptase inhibitor subgroups were similar. We identified three virological failures in the dolutegravir groups and one in the efavirenz group-we did not identify any integrase inhibitor mutations. We did not identify any dose-related clinical or laboratory toxic effects, with more drug-related adverse events of moderate-or-higher intensity in the efavirenz group (20%) than the dolutegravir group (8%). We did not judge that any serious adverse events were related to dolutegravir. INTERPRETATION: Dolutegravir was effective when given once daily without a pharmacokinetic booster and was well tolerated at all assessed doses. Our findings support the assessment of once daily 50 mg dolutegravir in phase 3 trials.