Clinical trial NCT00243230
Conditions: HIV Infections
Sponsor: Merck Sharp & Dohme LLC
Start date: 2005-09-19; Completion date: 2011-03-17
Enrollment: 116 participants; Allocation: RANDOMIZED; Intervention model: PARALLEL

Brief summary:
Vicriviroc (vye-kri-VYE-rock) is an investigational drug that belongs to a new class of drugs, called C-C chemokine receptor type 5 (CCR5) receptor blockers. This group of drugs blocks one of the ways human immunodeficiency virus (HIV) enters T-cells (the cells that fight infection). The purpose of this 48-week study is to evaluate 2 dose levels of vicriviroc in participants with HIV who have not responded adequately to standard HIV treatments. This study was designed to evaluate the safety and efficacy of doses of vicriviroc, when taken in combination with other HIV drugs, in terms of ability to decrease the level of HIV (viral load) in the blood. The primary objective of the study was to evaluate antiviral efficacy of two doses of Vicriviroc maleate compared to placebo in combination with a protease inhibitor (PI)-containing optimized antiretroviral therapy (ART) regimen in CCR5-tropic HIV infected individuals failing a standard ART regimen.

Detailed description:
This is a randomized, double-blind, placebo controlled, parallel-group, multi-center study of vicriviroc maleate in participants with HIV infected with CCR5-tropic virus only for whom standard antiretroviral treatment (ART) has failed. The study will evaluate the antiviral efficacy of two doses of vicriviroc (20 mg once daily (QD) and 30 mg QD) compared with placebo when added to optimized ART therapy. The optimized background regimen will be chosen by the investigator based on results of drug susceptibility tests, history of prior antiretroviral drug use by the participant, and drug toxicity. The background regimen must include at least 3 antiretroviral drugs (not including study drug), one of which must be a ritonavir-boosted protease inhibitor (≥100 mg ritonavir). There will be two interim analyses: when all participants have completed 12 weeks and 24 weeks of treatment, respectively. Based on the balance of safety and efficacy determined in these analyses, a dosage or dosages will be selected for further study in additional registrational trials. The primary efficacy analysis will be conducted when all participants have completed 48 weeks of treatment. After Week 48, participants who meet applicable criteria will be offered open label vicriviroc 30 mg QD, if appropriate, until the sponsor terminates the clinical development of vicriviroc. Additionally, participants who discontinue early from the study prior to Week 48 will be offered re-screening for the open label segment of the study.

Arms: arm 1: Vicriviroc 30 mg once daily (QD), orally (PO), plus an open-label optimized antiretroviral therapy (ART) regimen containing a ritonavir-boosted protease inhibitor (PI/r) for 48 weeks. arm 2: Vicriviroc 20 mg QD, PO, plus an open-label optimized ART regimen containing a PI/r for 48 weeks. arm 3: Placebo QD, PO, plus an open-label optimized ART regimen containing a PI/r for 48 weeks. arm 4: Vicriviroc 30 mg once daily (QD), orally (PO), plus an open-label optimized ART regimen containing a ritonavir-boosted protease inhibitor (PI/r) for up to 45 months.
Interventions: intervention 1: Vicriviroc 30 mg intervention 2: Vicriviroc 20 mg intervention 3: Placebo intervention 4: Placebo intervention 5: Background ART Regimen
Intervention descriptions: intervention 1: Three tablets of vicriviroc 10 mg once daily for 48 weeks (Double-blind Period) or for up to 45 months (Open Label Period). intervention 2: Two tablets of vicriviroc 10 mg once daily for 48 weeks. intervention 3: Three tablets of placebo once daily for 48 weeks. intervention 4: Two tablets of placebo once daily for 48 weeks. intervention 5: An open-label ritonavir-boosted optimized background ART regimen containing ≥3 drugs (including a protease inhibitor \[PI\]) selected for each individual study participant by the investigator. The optimized regimens most commonly include new nucleoside analogs (NRTIs) and a PI, usually "boosted" with concomitant ritonavir.

Protocol documents: