Another HIV entry
inhibitor study is halted

Disappointing clinical trial data has led to the halt of a clinical trial of Schering Plough's experimental HIV entry inhibitor vicriviroc, AIDSMap.com reports. Study data showed that HIV viral loads among treatment-naive study subjects increased soon after treatment with the drug was started.

The vicriviroc trial cancellation is the second major HIV entry inhibitor study to be halted within the last month. GlaxoSmithKline stopped all human trials of its experimental entry inhibitor aplaviroc after study data showed the drug carried a significant risk for severe liver toxicity.

Both vicriviroc and aplaviroc aimed to jam CCR5 receptors on the surface of immune system cells that HIV must latch on to in order to infect the cells. A CCR5 inhibitor being developed by Pfizer, called maraviroc, has been cleared for human tests. (Advocate.com)