The Intensive Pharmacokinetics Sub-study of Encore1 (ENCORE1-PK)
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ClinicalTrials.gov Identifier: NCT01271894 |
Recruitment Status
:
Completed
First Posted
: January 7, 2011
Last Update Posted
: May 13, 2013
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Condition or disease | Intervention/treatment | Phase |
---|---|---|
HIV Infection | Drug: Efavirenz | Phase 3 |
Study Type : | Interventional (Clinical Trial) |
Actual Enrollment : | 40 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Masking: | Double (Participant, Investigator) |
Primary Purpose: | Screening |
Official Title: | 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 |
Study Start Date : | September 2011 |
Actual Primary Completion Date : | May 2013 |
Actual Study Completion Date : | May 2013 |

Arm | Intervention/treatment |
---|---|
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
|
Drug: Efavirenz
400 mg once daily; given as 2 x 200 mg + 1 x placebo
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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
|
Drug: Efavirenz
600 mg once daily; given as 3 x 200 mg once
|
- 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 ]
- To compare the safety and tolerability of EFV 400 mg versus 600 mg given once daily. [ Time Frame: 48 weeks ]
- To investigate the correlation between EFV concentration measurements from dried blood spots and concentration measured in matched plasma samples. [ Time Frame: 48 weeks ]

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

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01271894
Argentina | |
Hospital J.M. Ramos Mejia | |
Buenos Aires, Argentina | |
South Africa | |
Desmond Tutu HIV Foundation | |
Cape Town, South Africa | |
Thailand | |
Thai Red Cross-AIDS Research Centre, HIV-NAT Research Collaboration | |
Bangkok, Thailand | |
United Kingdom | |
Chelsea and Westminister Hospital | |
London, United Kingdom |
Principal Investigator: | Marta Boffito, Dr. | Chelsea & Westminster Hospital |
Responsible Party: | Kirby Institute |
ClinicalTrials.gov Identifier: | NCT01271894 History of Changes |
Other Study ID Numbers: |
NCHECR-ENCORE1-PK |
First Posted: | January 7, 2011 Key Record Dates |
Last Update Posted: | May 13, 2013 |
Last Verified: | November 2012 |
Keywords provided by Kirby Institute:
HIV efavirenz pharmacokinetic |
Additional relevant MeSH terms:
HIV Infections Lentivirus Infections Retroviridae Infections RNA Virus Infections Virus Diseases Sexually Transmitted Diseases, Viral Sexually Transmitted Diseases Immunologic Deficiency Syndromes Immune System Diseases Efavirenz 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 |