Maraviroc/raltegravir simplification strategy following 6 months of quadruple therapy with tenofovir/emtricitabine/maraviroc/raltegravir in treatment-naive HIV patients.

Objective: We assessed the virological efficacy of a 6 month maraviroc/raltegravir simplification strategy following 6 months of quadruple therapy combining tenofovir disoproxil fumarate/emtricitabine with maraviroc/raltegravir.

Methods: HIV-1-infected naive patients were enrolled in an open label, single-arm, Phase 2 trial. All patients received maraviroc 300 mg twice daily, raltegravir 400 mg twice daily and tenofovir/emtricitabine for 24 weeks. Patients with stable HIV-RNA <50 copies/mL stopped tenofovir/emtricitabine at week (W) 24 and pursued maraviroc/raltegravir until W48. The primary endpoint was the virological response defined by HIV-RNA <50 copies/mL at W48.

Results: Thirty-three patients were analysed. Patients were mostly male (94%), Caucasians (91%), MSM (82%); their median age was 42 years. At baseline, median CD4 cell count was 453 cells/mm and HIV-RNA was 4.3 log copies/mL. All patients had CCR5-tropic viruses by genotropism and phenotropism assays. All but one patient had an HIV-RNA < 50 copies/mL at W24 and entered the simplification phase. Virological success was maintained at W48 in 88% (90% CI 79%-97%) of patients. N155H mutation was detected at failure in one patient. No tropism switch was observed. Raltegravir and maraviroc plasma exposure were satisfactory in 92% and 79% of 41 samples from 21 patients. Five severe adverse events (SAEs) were observed up to W48; none was related to the study drugs. Four patients presented grade 3 AEs; none was related to the study. No grade 4 AE was observed. No patient died.

Conclusions: Maraviroc/raltegravir maintenance therapy following a 6 month induction phase with maraviroc/raltegravir/tenofovir/emtricitabine was well tolerated and maintained virological efficacy in these carefully selected patients.