ViroPharma's maribavir fails pivotal trial

US drugmaker ViroPharma has reported that its Phase III trial evaluating maribavir used as prophylaxis in allogeneic stem cell, or bone marrow,  transplant patients did not achieve its primary endpoint. In the primary  analysis, there was no statistically-significant difference between  maribavir and placebo in reducing the rate of CMV disease. In addition,  the study failed to meet its key secondary endpoints.

The primary endpoint of the randomized, double-blind,  placebo-controlled, multicenter pivotal study was the incidence of CMV  disease within six months post-transplant. The incidence of disease was  4.4% for maribavir compared to 4.8% for placebo (p=0.79). The first of  four key secondary endpoints was the rate of initiation of anti-CMV  treatment within six months, which was 37.9% for maribavir compared to  40.5% for placebo (p=0.49). In addition, the incidence of  graft-versus-host disease, mortality and CMV disease-free survival was  comparable between the groups.

"We are extremely disappointed by the outcome of this pivotal study,"  said chief executive Vincent Milano. "We still have a significant amount  of work to do to fully understand this outcome and its impact on the  overall program," he added.