Aplaviroc is a CCR5

CCR5

C-C chemokine receptor type 5, also known as CCR5, is a protein that in humans is encoded by the CCR5 gene. CCR5 is a member of the beta chemokine receptors family of integral membrane proteins...

 entry inhibitor developed for the treatment of HIV

HIV

Human immunodeficiency virus is a lentivirus that causes acquired immunodeficiency syndrome , a condition in humans in which progressive failure of the immune system allows life-threatening opportunistic infections and cancers to thrive...

 infection. It is developed by GlaxoSmithKline

GlaxoSmithKline

GlaxoSmithKline plc is a global pharmaceutical, biologics, vaccines and consumer healthcare company headquartered in London, United Kingdom...

In October 2005, all studies of aplaviroc were discontinued due to liver toxicity

Hepatotoxicity

Hepatotoxicity implies chemical-driven liver damage.The liver plays a central role in transforming and clearing chemicals and is susceptible to the toxicity from these agents. Certain medicinal agents, when taken in overdoses and sometimes even when introduced within therapeutic ranges, may injure...

 concerns. Some authors have claimed that evidence of poor efficacy may have contributed to termination of the drug's development; the ASCENT study, one of the discontinued trials, showed aplaviroc to be inferior to efavirenz

Efavirenz

Efavirenz is a non-nucleoside reverse transcriptase inhibitor and is used as part of highly active antiretroviral therapy for the treatment of a human immunodeficiency virus type 1....

as the third component of a three-drug regimen.