ABSTRACT
OBJECTIVE: To assess efficacy and safety of cobicistat versus ritonavir as pharmacoenhancers for atazanavir when administered with emtricitabine/tenofovir df as initial treatment for HIV-1 infection. DESIGN: Randomized, partially placebo-controlled, double-blind, multicenter study. PARTICIPANTS: Antiretroviral treatment-naive adults, screening HIV-1 RNA of at least 5000 copies/ml and CD4 cell count more than 50 cells/µl. INTERVENTION: Randomized 2 : 1 (stratified by HIV RNA ≤ or >100,000 copies/ml) to receive placebo-blinded once-daily cobicistat 150 mg or ritonavir 100 mg with open-label atazanavir and fixed-dose emtricitabine/tenofovir df. MAIN OUTCOME MEASURES: Efficacy and safety at weeks 24 and 48. RESULTS: Eighty-four percent of ATV/co participants and 86% of ATV/r participants suppressed HIV-1 RNA (<50 copies/ ml) at week 24, and 82 and 86% at week 48, respectively, and mean CD4 cell count increased 203 and 199 cells/µl at week 24 and 208 and 177 cells/µl at week 48, respectively. Study treatment discontinuation due to adverse events occurred in 4% ATV/co and in 3% ATV/r participants through 48 weeks. Treatment-related adverse events occurred in 36% ATV/co and 48% ATV/r participants; hyperbilirubinemia occurred in 96 and 100%, and ocular icterus or jaundice occurred in 14 and 17%, respectively. Mean estimated glomerular filtration rate (Cockcroft-Gault, ml/min) decrease occurred in both treatment groups and was evident at week 2 (ATV/co -9, ATV/r -4), reached a nadir by week 24 (-15, -14, respectively), and did not progress further through week 48 (-13, -14). CONCLUSION: Using cobicistat and ritonavir as pharmacoenhancers for atazanavir and administered with emtricitabine/tenofovir df achieved comparable rates of virologic suppression and CD4 cell count increase with satisfactory safety profiles.
Subject(s)
Adenine/analogs & derivatives , Antiretroviral Therapy, Highly Active , Carbamates/administration & dosage , Deoxycytidine/analogs & derivatives , HIV Infections/drug therapy , HIV-1 , Oligopeptides/administration & dosage , Organophosphonates/administration & dosage , Pyridines/administration & dosage , Ritonavir/administration & dosage , Thiazoles/administration & dosage , Adenine/administration & dosage , Atazanavir Sulfate , CD4 Lymphocyte Count , Cobicistat , Deoxycytidine/administration & dosage , Double-Blind Method , Drug Administration Schedule , Emtricitabine , Female , Humans , Male , RNA, Viral , Tenofovir , Treatment OutcomeABSTRACT
OBJECTIVE: To assess the safety and efficacy of two, single-tablet regimens for the initial treatment of HIV infection. DESIGN: Phase 2, randomized, double-blind, double-dummy, multicenter, active-controlled study. METHODS: Antiretroviral treatment-naive adults with a screening HIV-1 RNA at least 5000 copies/ml and a CD4 cell count more than 50 cells/µl were randomized 2: 1 to receive fixed-dose combination tablets of elvitegravir/cobicistat/emtricitabine/tenofovir disoproxil fumarate (EVG/COBI/FTC/TDF; N = 48) or efavirenz/emtricitabine/tenofovir disoproxil fumarate (EFV/FTC/TDF; n = 23) for 48 weeks. The primary endpoint was proportion of participants with HIV-1 RNA less than 50 copies/ml at week 24. RESULTS: Participants receiving EVG/COBI/FTC/TDF exhibited a more rapid decline in HIV-1 RNA and a greater proportion suppressed viral load to less than 50 copies/ml than participants receiving EFV/FTC/TDF. Both EVG/COBI/FTC/TDF and EFV/FTC/TDF resulted in high rates of viral suppression and increases in CD4 cell count. Ninety and 83% of participants suppressed HIV-1 RNA to less than 50 copies/ml both at the 24-week and 48-week visits for EVG/COBI/FTC/TDF and EFV/FTC/TDF, respectively. Once-daily administration of EVG/COBI/FTC/TDF provided a mean EVG trough concentration 10-fold over its protein binding-adjusted IC(95) across study visits. EVG/FTC/TDF/GS-9350 was generally well tolerated with a lower rate of drug-related central nervous system (17%) and psychiatric (10%) adverse events versus EFV/FTC/TDF (26 and 44%, respectively). Decreases in estimated glomerular filtration rate occurred within the first few weeks of dosing in participants receiving EVG/COBI/FTC/TDF, remained within the normal range and did not progress at week 24 or 48; no participant experienced a clinical adverse event or discontinued study drug due to changes in serum creatinine or renal function. CONCLUSION: Once-daily EVG/COBI/FTC/TDF achieved and maintained a high rate of virologic suppression with fewer central nervous system and psychiatric adverse events compared to a current standard-of-care regimen of EFV/FTC/TDF.
