Schering-Plough reports positive phase II vicriviroc results

Schering-Plough has announced the results of a phase II clinical trial showing that its investigational CCR5 antagonist, vicriviroc, displayed robust and sustained viral suppression during 48 weeks of use in treatment-experienced patients with HIV.

The compound was administered in a once-daily dose in combination with an optimised background regimen of ritonavir-boosted protease inhibitor-containing antretroviral therapy.

Vicriviroc is an extracellular HIV infection inhibitor that operates by antagonism of the CCR5 co-receptor to block the entry of infectious virions into uninfected CD4 cells in the body.

In the study, the Aids Clinical Trial Group reported a median decrease in viral load of 1.92 and 1.44 log10 copies per millilitre and a median increase in CD4 cell count of 130 and 96 cells per microlitre for the 10 milligram and 15 milligram vicrivoc treatment groups respectively.

Roy Gulick, professor at the Weill Medical College of Cornell University, said: “These 48-week data establish the durability of viral suppression with a vicriviroc-containing regimen in treatment-experienced patients with advanced HIV disease and are the first to demonstrate the sustained effects of a CCR5- based regimen through 48 weeks.”

He added that there exists an urgent medical need for innovative antiviral compounds with new modes of action and distinct resistance profiles for the treatment of HIV patients, while the firm anticipates further clinical trials of the compound in conjunction with antiretroviral medications.

In May 2007, Schering-Plough reported that it had received a positive opinion from the Committee for Medicinal Products for Human Use of the European Medicines Agency for a combination of Pegintron (peginterferon alfa-2b) and Rebetol (ribavirin) for hepatitis C patients co-infected with HIV.