Aplaviroc
Aplaviroc is a CCR5 entry inhibitor that belongs to a class of 2,5-diketopiperazines developed for the treatment of HIV infection. It was developed by GlaxoSmithKline.
In October 2005, all studies of aplaviroc were discontinued due to liver toxicity 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 under-effective in many patients even at high concentrations.