title: Efficacy and safety of maraviroc vs. efavirenz in treatment-naive patients with HIV-1: 5-year findings.
abstract: OBJECTIVE
  Maraviroc, a chemokine co-receptor type 5 (CCR5) antagonist, has demonstrated comparable efficacy and safety to efavirenz, each in combination with zidovudine/lamivudine, over 96 weeks in the Maraviroc vs. Efavirenz Regimens as Initial Therapy (MERIT) study. Here we report 5-year findings.
  
  
  METHODS
  A randomized, double-blind, multicenter phase IIb/III study with an open-label extension phase.
  
  
  METHODS
  Treatment-naive patients with CCR5-tropic HIV-1 infection (Trofile) received maraviroc 300 mg twice daily or efavirenz 600 mg once daily, and zidovudine/lamivudine 300 mg/150 mg twice daily. After the last patient's week 96 visit, the study was unblinded and patients could enter a nominal 3-year open-label phase. Endpoints at the 5-year nominal visit (week 240) included proportion of patients (CCR5 tropism re-confirmed by enhanced sensitivity Trofile) with viral load (plasma HIV-1 RNA) below 50 and 400 copies/ml, and change from baseline in CD4(+) cell count, as well as safety.
  
  
  RESULTS
  The proportion of patients maintaining viral load below 50 copies/ml was similar between treatment arms throughout the study and at week 240 (maraviroc 50.8% vs. efavirenz 45.9%). Maraviroc-treated patients had a greater increase from baseline in mean CD4(+) cell count than efavirenz-treated patients at week 240 (293 vs. 271 cells/μl, respectively). Fewer patients on maraviroc vs. efavirenz experienced treatment-related adverse events (68.9 vs. 81.7%) and discontinued as a result of any adverse event (10.6 vs. 21.3%).
  
  
  CONCLUSIONS
  Maraviroc maintained similar long-term antiviral efficacy to efavirenz over 5 years in treatment-naive patients with CCR5-tropic HIV-1. Maraviroc was generally well tolerated with no unexpected safety findings or evidence of long-term safety concerns.
authors.affiliation: aKirby Institute, University of New South Wales, Sydney, Australia bPfizer Inc, Groton, Connecticut, USA cUniversity of Witwatersrand, Johannesburg dPrivate Practice, Pretoria, South Africa eOrlando Immunology Center, Orlando, Florida, USA fSaint-Pierre University Hospital, Brussels, Belgium gUniversity of Toronto, Toronto, Canada hSan Raffaele Scientific Institute, Milan, Italy iPfizer Inc, New York jUniversity of Alabama at Birmingham, Birmingham, Alabama, USA kPfizer Global Research and Development, Sandwich, UK.
authors.forename: David A
authors.initials: DA
authors.lastname: Cooper
authors.forename: Jayvant
authors.initials: J
authors.lastname: Heera
authors.forename: Prudence
authors.initials: P
authors.lastname: Ive
authors.forename: Mariette
authors.initials: M
authors.lastname: Botes
authors.forename: Edwin
authors.initials: E
authors.lastname: Dejesus
authors.forename: Robert
authors.initials: R
authors.lastname: Burnside
authors.forename: Nathan
authors.initials: N
authors.lastname: Clumeck
authors.forename: Sharon
authors.initials: S
authors.lastname: Walmsley
authors.forename: Adriano
authors.initials: A
authors.lastname: Lazzarin
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Mukwaya
authors.forename: Michael
authors.initials: M
authors.lastname: Saag
authors.forename: Elna
authors.initials: E
authors.lastname: van Der Ryst
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000480:Alkynes; D019380:Anti-HIV Agents / Q000009:adverse effects* / Q000627:therapeutic use*; D023241:Antiretroviral Therapy, Highly Active / Q000009:adverse effects* / Q000379:methods*; D048588:Benzoxazines / Q000009:adverse effects / Q000627:therapeutic use; D018791:CD4 Lymphocyte Count; D003510:Cyclohexanes / Q000009:adverse effects / Q000627:therapeutic use; D003521:Cyclopropanes; D004311:Double-Blind Method; D064420:Drug-Related Side Effects and Adverse Reactions / Q000453:epidemiology; D005260:Female; D015658:HIV Infections / Q000188:drug therapy* / Q000821:virology*; D015497:HIV-1 / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D000077592:Maraviroc; D008875:Middle Aged; D016896:Treatment Outcome; D014230:Triazoles / Q000009:adverse effects / Q000627:therapeutic use; D019562:Viral Load; D055815:Young Adult
chemical_list: D000480:Alkynes; D019380:Anti-HIV Agents; D048588:Benzoxazines; D003510:Cyclohexanes; D003521:Cyclopropanes; D014230:Triazoles; C098320:efavirenz; D000077592:Maraviroc