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The Intensive Pharmacokinetics Sub-study of Encore1 (ENCORE1-PK)

This study has been completed.
Sponsor:
Collaborator:
Chelsea and Westminster NHS Foundation Trust
Information provided by (Responsible Party):
Kirby Institute
ClinicalTrials.gov Identifier:
NCT01271894
First received: January 5, 2011
Last updated: May 10, 2013
Last verified: November 2012

January 5, 2011
May 10, 2013
September 2011
May 2013   (final data collection date for primary outcome measure)
To compare the pharmacokinetic parameters of EFV determined from blood collected over a 24-hour dosing interval in blinded samples from participants taking either 600 mg or 400 mg once daily in combination with Truvada. [ Time Frame: 48 weeks ] [ Designated as safety issue: No ]
To compare the pharmacokinetic parameters of plasma EFV (Cmin and GMR) over a 24-hour dosing interval in blinded samples from participants taking 600mg EFV or 400mg EFV once daily in combination with Truvada. [ Time Frame: 48 weeks ] [ Designated as safety issue: Yes ]
Complete list of historical versions of study NCT01271894 on ClinicalTrials.gov Archive Site
  • To compare the safety and tolerability of EFV 400 mg versus 600 mg given once daily. [ Time Frame: 48 weeks ] [ Designated as safety issue: Yes ]
  • To investigate the correlation between EFV concentration measurements from dried blood spots and concentration measured in matched plasma samples. [ Time Frame: 48 weeks ] [ Designated as safety issue: No ]
  • To compare the safety and tolerability of 400mg versus 600mg efavirenz dose. [ Time Frame: 48 weeks ] [ Designated as safety issue: Yes ]
  • To investigate the correlation between EFV concentration measurements from dried blood spots and individual matched plasma samples. [ Time Frame: 48 weeks ] [ Designated as safety issue: Yes ]
Not Provided
Not Provided
 
The Intensive Pharmacokinetics Sub-study of Encore1 (ENCORE1-PK)
The Intensive Pharmacokinetics 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 Two Nucleotide Reverse Transcriptase Inhibitors (N(t)RTI) in Antiretroviral-naïve HIV-infected Individuals Over 96 Weeks

Safety and efficacy are key issues in antiretroviral therapy (ART) selection. Efavirenz (EFV) is an important component of combination ART in treatment naive individuals. Like many drugs, there are inter-individual differences in the efficacy and tolerability of EFV. The Encore1 study provides an opportunity to examine the pharmacokinetics (PK)(processes by which a drug is absorbed, distributed, metabolized, and eliminated by the body) of EFV in blood samples collected over a 24-hour dosing interval in participants receiving either standard 600 mg or reduced 400 mg dose EFV once daily.

This sub-study will investigate the relationships between dosage, EFV plasma concentrations, toxicity and virological efficacy. EFV concentrations in dried blood spots and matched plasma and will be evaluated to determine the utility of dried blood spot measurements in measuring EFV plasma concentrations. Measurements dried blood spots could potentially be a cheap and easy alternative to measurements in plasma. Dried blood spots can be easily collected from venous blood or fingerprick, do not need plasma separation and potentially need less stringent storage conditions during shipment.

Interventional
Phase 3
Allocation: Randomized
Endpoint Classification: Pharmacokinetics Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Investigator)
Primary Purpose: Screening
HIV Infection
  • Drug: Efavirenz
    600 mg once daily; given as 3 x 200 mg once
  • Drug: Efavirenz
    400 mg once daily; given as 2 x 200 mg + 1 x placebo
  • Experimental: Reduced dose Efavirenz arm
    Participants randomized in main study to receive EFV (400 mg once daily; 2 x 200 mg + 1 x placebo once daily) plus tenofovir/emtricitabine (300/200 mg) fixed-dose combination once daily
    Intervention: Drug: Efavirenz
  • Active Comparator: Normal Efavirenz dose arm
    Patients randomized in the main study to receive EFV (600 mg once daily; 3 x 200 mg once daily) plus tenofovir/emtricitabine (300/200 mg) fixed-dose combination once daily
    Intervention: Drug: Efavirenz
Not Provided

*   Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
 
Completed
40
May 2013
May 2013   (final data collection date for primary outcome measure)

All participants enrolled into the main Encore1 study at participating sub-study sites will be eligible to participate.

Participants must meet the following additional inclusion criteria prior to intensive pharmacokinetic assessment. Inclusion Criteria:

  • provide written sub-study consent at or before week 0
  • taken randomized study drugs for at least 4 weeks but less than 8 weeks
  • taken EFV in the evening for at least 7 days
  • taken all EFV doses over the 3 preceding days.
Both
16 Years and older
No
Contact information is only displayed when the study is recruiting subjects
Argentina,   South Africa,   Thailand,   United Kingdom
 
NCT01271894
NCHECR-ENCORE1-PK
No
Kirby Institute
Kirby Institute
Chelsea and Westminster NHS Foundation Trust
Principal Investigator: Marta Boffito, Dr. Chelsea & Westminster Hospital
Kirby Institute
November 2012

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP