Darunavir/cobicistat/emtricitabine/tenofovir alafenamide in treatment-naive patients with HIV-1: subgroup analyses of the phase 3 AMBER study

Background: The once-daily, single-tablet regimen darunavir/cobicistat/emtricitabine/tenofovir alafenamide (D/C/F/TAF) 800/150/200/10mg is approved for the treatment of HIV-1 infection. The 48-week efficacy and safety of D/C/F/TAF versus darunavir/cobicistat+emtricitabine/tenofovir disoproxil fumarate (control) in treatment-naive adults were demonstrated in the phase 3 AMBER study.Objective: To describe AMBER outcomes across patient subgroups based on demographic and clinical characteristics at baseline.Methods: AMBER patients had viral load (VL) >= 1000 copies/mL, CD4(+) cell count >50 cells/mu L, and genotypic susceptibility to darunavir, emtricitabine, and tenofovir. Primary endpoint was the proportion of patients with virologic response (VL <50 copies/mL; FDA snapshot). Safety was assessed by adverse events, estimated glomerular filtration rate (cystatin C; eGFR(cystC)), and bone mineral density. Outcomes were assessed by age (<less than or equal to>/>50 years), gender, race (black/non-black), baseline VL (<=/>100,000 copies/mL), baseline CD4(+) cell count (</<greater than or equal to>200 cells/mu L), and baseline WHO clinical stage of HIV infection (1/2).Results: For the 725 AMBER patients (D/C/F/TAF: 362; control: 363), virologic response rates at week 48 were similar with D/C/F/TAF (91%) and control (88%), and this was consistent across all subgroups. Adverse event rates were similar in both arms, although numerically higher among patients >50 years and women, relative to their comparator groups, regardless of treatment arm (notably, sample sizes were small for patients >50 years and women). Improvements in eGFR(cystC) and stable bone mineral density were observed with D/C/F/TAF overall, and results were generally consistent across subgroups.Conclusions: For treatment-naive patients in AMBER, initiating therapy with the D/C/F/TAF single-tablet regimen was an effective and well-tolerated option, regardless of demographic or clinical characteristics.