Brief Report: Efficacy and Safety of Switching to Coformulated Elvitegravir, Cobicistat, Emtricitabine, and Tenofovir Alafenamide (E/C/F/TAF) in Virologically Suppressed Women

J Acquir Immune Defic Syndr. 2018 Jun 1;78(2):209-213. doi: 10.1097/QAI.0000000000001663.

Abstract

Background: The integrase inhibitor regimen [elvitegravir/cobicistat/emtricitabine/tenofovir disoproxil fumarate (TDF)] demonstrated superior efficacy when compared with a protease inhibitor regimen [ritonavir-boosted atazanavir (ATV + RTV) and FTC/TDF] in 575 treatment-naive women at week 48. We investigated the efficacy, safety, and tolerability of switching to a TAF-based, single-tablet regimen containing elvitegravir, cobicistat, FTC, and tenofovir alafenamide (E/C/F/TAF) versus remaining on ATV + RTV plus FTC/TDF.

Methods: After completing the initial randomized, blinded phase, virologically suppressed (HIV-1 RNA <50 copies/mL) women on ATV + RTV plus FTC/TDF were rerandomized (3:1) to receive open-label E/C/F/TAF versus remaining on their current regimen. The primary end point was proportion of participants with plasma HIV-1 RNA <50 copies per milliliter at week 48 (U.S. FDA snapshot algorithm), with a prespecified noninferiority margin of 12%. Safety [adverse events (AEs)] and tolerability were also assessed.

Results: Of 575 women originally randomized and treated in the blinded phase, 159 were rerandomized to switch to E/C/F/TAF and 53 to remain on ATV + RTV plus FTC/TDF. At week 48, virologic suppression was maintained in 150 (94%) of women on E/C/F/TAF and 46 (87%) on ATV + RTV plus FTC/TDF [difference 7.5% (95% confidence interval -1.2% to 19.4%)], demonstrating noninferiority of E/C/F/TAF to ATV + RTV and FTC/TDF. Incidence of AEs was similar between groups; study drug-related AEs were more common with E/C/F/TAF (11% versus 4%).

Conclusions: Switching to E/C/F/TAF was noninferior to continuing ATV + RTV plus FTC/TDF in maintaining virologic suppression and was well tolerated at 48 weeks.

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adenine / administration & dosage
  • Adenine / analogs & derivatives*
  • Adenine / pharmacology
  • Adult
  • Anti-HIV Agents / administration & dosage
  • Anti-HIV Agents / pharmacology*
  • Antiretroviral Therapy, Highly Active / methods
  • Cobicistat / administration & dosage
  • Cobicistat / pharmacology*
  • Double-Blind Method
  • Drug Combinations
  • Drug Resistance, Viral
  • Drug-Related Side Effects and Adverse Reactions
  • Emtricitabine / administration & dosage
  • Emtricitabine / pharmacology*
  • Female
  • HIV Infections / drug therapy*
  • HIV-1
  • Humans
  • Integrase Inhibitors / pharmacology
  • Protease Inhibitors / pharmacology
  • Quinolones / administration & dosage
  • Quinolones / pharmacology*
  • RNA, Viral / blood

Substances

  • Anti-HIV Agents
  • Drug Combinations
  • Integrase Inhibitors
  • JTK 303
  • Protease Inhibitors
  • Quinolones
  • RNA, Viral
  • GS-7340
  • Emtricitabine
  • Adenine
  • Cobicistat