Good viral suppression with S-P's vicriviroc

US drug major Schering-Plough reported strong results from an ongoing Phase II clinical trial of its anti-HIV drug candidate vicriviroc. According to the firm, the CCR5 receptor antagonist demonstrated potent and sustained viral suppression after 24 weeks of therapy in 118 treatment-experienced HIV patients, when administered in once-daily doses in combination with an optimized ritonavir-boosted protease inhibitor-containing antiretroviral regimen.

In the study, data from which were presented at the 16th International AIDS Conference in Toronto, Canada, viral load decrease was significantly greater for patients in each vicriviroc group compared to the control arm at day 14 and at week 24 (p<0.01), and was not different between the vicriviroc groups (p>0.05). Although there was no statistical difference in the viral load reductions between the three vicriviroc arms, a higher rate of virologic failure and emergence of X4 virus was observed at the lowest dose of 5mg.

This is the first trial with a CCR5 receptor antagonist for HIV to report 24-week treatment results. Researchers from the US National Institutes of Health-sponsored Adult AIDS Clinical Trial Group, which is conducting the study, presented the data during a late-breaker session at the Toronto conference.