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Completed

NCT Number: NCT01011413

Safety and Efficacy of Reduced Versus Standard Dose Efavirenz (EFV) Plus Two Nucleotides in Antiretroviral-naïve Adults.

Clinical data suggests that the standard dose of the anti-HIV medication, efavirenz (EFV), could be reduced without compromising its effectiveness. Lower drug doses could have fewer side effects and would make EFV more affordable. The purpose of this study is to compare the safety and effectiveness, over 96 weeks, of standard (600mg) versus reduced dose (400mg) EFV in controlling HIV as part of initial combination antiretroviral therapy.

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Key information

Age range

16 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Phase 3

Primary location

St Vincent's Hospital

Sydney, New South Wales, 2010, Australia

About this study

In this international, multicenter trial, 630 HIV infected patients who have not received any previous treatment for their HIV-infection will be enrolled. Participants will be randomized equally (1:1) to receive Truvada (tenofovir and emtricitabine) with either the standard or reduced dose of EFV. Neither the study doctor nor the participant will know which treatment the participant is receiving. Physical examinations, laboratory analyses and questionnaires will be performed at the 11 study visits at screening, baseline (Week 0), Weeks 4, 12, 24, 36, 48, 60, 72, 84 and 96. The primary aim of this study is to compare between treatment groups the proportion of patients with undetectable HIV viral load (HIV RNA < 200 copies/mL) after 48 weeks. Information on immune function, drug adherence, resistance to antiretrovirals, quality of life, mental state and HIV-related conditions will also be collected. Blood samples will be collected for future testing. Interim analyses will be performed when the first 125 participants in each treatment group reach week 24 and when all participants reach week 24. These interim analyses will provide an early check that the reduced dose of EFV suppresses HIV infection as effectively as the standard dose of EFV. A follow-up analysis will be performed when all participants reach week 96.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • HIV-1 positive by licensed diagnostic test
  • aged >16 years of age (or minimum age as determined by local regulations or as legal requirements dictate)
  • 50 < cluster of differentiation (CD)4 <500 cells/µL
  • No prior AIDS-defining illness, using the Center for Diseases Control 1993 Case Definition (except pulmonary tuberculosis)
  • HIV RNA ≥1000 copies/mL
  • no prior exposure to antiretroviral therapy (ART) (including short course ART for preventing MTCT)
  • calculated creatinine clearance (CLCr) more than or equal to 50 mL/min (Cockcroft-Gault formula)
  • provision of written informed consent.

Exclusion criteria

  • the following laboratory values:
  • absolute neutrophil count (ANC) <500 cells/μL
  • hemoglobin <7.0 g/dL
  • platelet count <50,000 cells/μL
  • alanine aminotransferase and/or aspartate aminotransferase >5 x upper limit of normal
  • pregnant women or nursing mothers
  • active opportunistic or malignant disease not under adequate control
  • use of immunomodulators within 30 days prior to screening
  • use of any prohibited medications
  • current alcohol or illicit substance use that might adversely affect study participation

Treatment and study plan

Efavirenz 600mg

Drug

3 x EFV 200 milligram (mg) tablets once daily

Other names: Matrix EFV 200mg tablets

Efavirenz 400mg

Drug

2 x EFV 200 milligram (mg) tablets plus 1x matched EFV placebo tablet once daily

Other names: Matrix EFV 200mg tablets, Matrix EFV 200mg matched placebo tablets.

Primary outcomes

  1. Percentage of Participants With Plasma HIV-1 RNA <200 Copies/mL 48 Weeks After Randomisation

    Time frame: 48 weeks

    Percentage of participants in each of the treatment arms with centrally quantified plasma HIV-1 RNA viral load <200 copies/mL 48 weeks after randomisation.

Secondary outcomes

  1. Percentage of Participants With Plasma HIV-1 RNA <400 Copies/mL and <50 Copies/mL at 48 and 96 Weeks After Randomisation

    Time frame: Baseline and 2 years

    Percentage of participants in each of the two treatment arms with plasma HIV-1 RNA <400 copies/mL and <50 copies/mL at 48 and 96 weeks after randomisation

  2. Mean Change From Baseline in CD4+ T-cell Count

    Time frame: Baseline and 2 years

    Mean change from baseline to week 96 in CD4+ T-cell count/mm3 between the two treatment arms

  3. Clinical Endpoints: Opportunistic Disease or Death, and Serious Non-AIDS-defining Events and Non-AIDS-related Mortality

    Time frame: up to 2 years

    Number of participants in each randomised arm diagnosed with a serious non-AIDS defining event, who die from an AIDS-defining event, who die from a non-AIDS-defining event

  4. Change From Baseline in Metabolic Endpoints

    Time frame: Baseline and 2 years

    Change from baseline to week 96 in fasted total cholesterol, high density cholesterol and low density cholesterol, and glucose between randomised treatment arms

  5. Adherence: Median Scores of Self-reported Adherence to Randomised Study Medications

    Time frame: 2 years

    AIDS Clinical Trials Group (ACTG) 7-day adherence questionnaire scores. Maximum value is all pills taken every day; minimum value is no pills taken per day. Higher scores indicate a better outcome.

  6. Change From Baseline in Fasted Insulin Levels

    Time frame: Baseline and 2 years

    Change from baseline to week 96 in fasted insulin levels

  7. Change in Selected Serum Biochemical Parameters

    Time frame: Baseline and 2 years

    Change from baseline to week 96 in alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase levels between randomised treatment arms

  8. Change From Baseline in Estimate Creatinine Clearance

    Time frame: Baseline and 2 years

    Change from baseline to week 96 in estimate creatinine clearance between randomised treatment arms

  9. Steady-state Efavirenz Concentrations

    Time frame: Week 4

    Steady-state efavirenz mid-dosing interval plasma concentrations

Sponsors and collaborators

Lead sponsor

Kirby Institute

Other Gov

Registry information

Official study title

A Randomised, Double-blind, Placebo-controlled, Trial to Compare the Safety and Efficacy of Reduced Dose Versus Standard Dose EFV Plus Two Nucleotides (N(t)RTI) in Antiretroviral-naïve HIV-infected Adults Over 96 Weeks

Acronym: ENCORE1

Important dates

Study start
2011
Primary completion
2013
Study completion
2014
First posted
Nov 11, 2009
Registry last updated
Feb 21, 2020

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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