UPDATE: ViroPharma discontinues Ph III maribavir trial, shares fall 5.3%

Shares in USA-based ViroPharma fell 5.3% to $6.23 on February 13, after the firm cancelled a Phase III trial evaluating maribavir to  prevent cytomegalovirus disease in liver transplant patients. All  subjects receiving the investigational drug are being moved to the  current standard-of-care. The decision was based on the results of a  late-stage study of the antiviral in stem-cell transplant patients, and  a recommendation from its Independent Data Monitoring Committee, which  considered the rate of viremia in both arms of the study. The abandoned  Phase III study was a randomized, double-blind, multicenter trial  intended to enroll 348 subjects. The primary efficacy endpoint was the  incidence of CMV disease within six months post transplantation, which  is expected to be approximately 12% in the oral ganciclovir control arm  of the study, based on data from published literature.