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The Neurocognitive Sub-study of Encore1

This study has been completed.
The HIV Netherlands Australia Thailand Research Collaboration
Information provided by (Responsible Party):
Kirby Institute Identifier:
First received: January 19, 2012
Last updated: September 18, 2013
Last verified: September 2013
The purpose is to investigate whether HIV and HIV medication can affect certain areas of brain function. This study will look at possible changes in brain function including memory, concentration and thought processes to see if there are any differences between the two doses of efavirenz used in the Encore1 study and also the level of efavirenz in the blood

Condition Intervention Phase
HIV Drug: Efavirenz Phase 3

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary Purpose: Screening
Official Title: The Neurocognitive Sub Study of Encore1:A Randomised, Double‐Blind, Placebo‐Controlled, Clinical Trial to Compare the Safety and Efficacy of Reduced Dose Efavirenz (EFV) With Standard Dose EFV Plus 2N(t)RTI in Antiretroviral‐naïve HIV‐Infected Individuals Over 96 Weeks A Randomised, Double-blind, Placebo-controlled, Clinical Trial to Compare the Safety and Efficacy of Reduced Dose Efavirenz (EFV) With Standard Dose EFV Plus Two Nucleotide Reverse Transcriptase Inhibitors (N(t)RTI) in Antiretroviral-naïve HIV-infected Individuals Over 96 Weeks

Resource links provided by NLM:

Further study details as provided by Kirby Institute:

Primary Outcome Measures:
  • The primary endpoint is the comparison between of neurocognitive function in patients initiating sdEFV and 400EFV [ Time Frame: 48 weeks ]

Secondary Outcome Measures:
  • The association between week 4 plasma EFV levels and change from baseline neurocognitive function to week 4 and 24. [ Time Frame: Week 24 ]
  • To assess dynamic changes in neurocognitive function over the total duration of follow-up. [ Time Frame: 96 weeks ]

Enrollment: 71
Study Start Date: January 2012
Study Completion Date: March 2013
Primary Completion Date: March 2013 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Reduced dose Efavirenz arm
Patient's on main study that was randomised to receive TDF (300mg qd)/FTC (200mg qd) + EFV (400mg qd; 2 x 200mg + 1 x 200mg placebo qd).
Drug: Efavirenz
400mg qd; 2 x 200mg
Active Comparator: Normal Efavirenz dose arm
Patient's on main study randomised to receive tenofovir (TDF) (300mg qd)/emtricitabine (FTC) (200mg qd) + EFV (600mg qd; 3 x 200mg qd)
Drug: Efavirenz
600mg qd; 3 x 200mg qd


Ages Eligible for Study:   16 Years and older   (Child, Adult, Senior)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • All subjects entering into the main study protocol at participating centres will be eligible to enter this sub-study.

Exclusion Criteria:

  • Existing neurological brain disease
  • Recent (<6months ) head injury
  • Current major depression or psychosis
  • Current alcohol abuse
  • Intended use of recreational drugs during study period
  • Uncontrolled medical conditions deemed to potentially interfere with cognitive function (e.g. uncontrolled diabetes, pyrexial illness, uraemia etc)
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT01516060

HIVNAT Research Collaboration
Bangkok, Thailand
Sponsors and Collaborators
Kirby Institute
The HIV Netherlands Australia Thailand Research Collaboration
Principal Investigator: Rebekah Puls Kirby Institute
  More Information

Responsible Party: Kirby Institute Identifier: NCT01516060     History of Changes
Other Study ID Numbers: Encore1-NC
Study First Received: January 19, 2012
Last Updated: September 18, 2013

Additional relevant MeSH terms:
Reverse Transcriptase Inhibitors
Nucleic Acid Synthesis Inhibitors
Enzyme Inhibitors
Molecular Mechanisms of Pharmacological Action
Anti-Retroviral Agents
Antiviral Agents
Anti-Infective Agents
Cytochrome P-450 CYP2C9 Inhibitors
Cytochrome P-450 Enzyme Inhibitors
Cytochrome P-450 CYP2C19 Inhibitors
Cytochrome P-450 CYP2B6 Inducers
Cytochrome P-450 Enzyme Inducers
Cytochrome P-450 CYP3A Inducers processed this record on September 21, 2017