
Merck & Co. on Wednesday
announced that it will not seek FDA
approval for the use of its
experimental HIV drug vicriviroc in
treatment-experienced patients after the drug failed to meet primary endpoints in
two Phase III trials. The study results were presented at the Conference on Retroviruses and Opportunistic Infections.
The studies, which together enrolled 857 treatment-experienced patients with
HIV, found that vicriviroc failed to demonstrate superiority over placebo in
combination with optimised background therapy. Specifically, 64 percent of
patients in the vicriviroc arm achieved pre-determined viral load rates at 48 weeks, compared to 62 percent in the placebo arm.
Commenting on the findings, Lisa Dunkle, Merck's executive director clinical
research, said “it is becoming increasingly difficult for an additional HIV
medicine to demonstrate a significant incremental benefit as the fourth or fifth drug added to optimised background therapy.”
The drugmaker said that an ongoing Phase II study of vicriviroc in treatment-naïve HIV-infected patients will continue.
