Vicriviroc (SCH 417690) in Combination Treatment With Optimized ART Regimen in Experienced Participants (VICTOR-E1) (MK-7690-020/P03672)

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.