Merck Announces Phase 3 Results of Antiviral Meds

Feb 27, 2017


Merck & Co. Inc., known as MSD outside the United States and Canada, announced results of the Phase 3 clinical study of letermovir, an investigational antiviral medicine for the prevention of clinically significant cytomegalovirus (CMV) infection in adult CMV-seropositive recipients of a bone marrow transplant (BMT). CMV is a common virus that infects people of all ages.

The study met its primary efficacy endpoint, showing that significantly fewer patients with undetectable CMV DNA at the start of study treatment developed clinically significant CMV infection through Week 24 post-HSCT. In the study, letermovir prophylaxis was associated with lower all-cause mortality through Week 24 post-HSCT. Based on these results, Merck plans to submit regulatory applications for the approval of letermovir in the United States and European Union (EU) in 2017.

“These results showed that letermovir prophylaxis beginning after HSCT and continuing through Day 100 post-transplant significantly reduced CMV infection requiring preemptive antiviral therapy through Week 24 post-transplant,” said Dr. Francisco M. Marty, associate professor of medicine at Harvard Medical School and attending physician in transplant and oncology infectious diseases at Dana-Farber Cancer Institute and Brigham and Women’s Hospital, who presented the data.

Results from the study were presented for the first time at the BMT Tandem Meetings, the combined annual meetings of the Center for International Blood & Marrow Transplant Research (CIBMTR) and the American Society for Blood and Marrow Transplantation (ASBMT), in Orlando, Fla., Feb. 22-26.

Efficacy was consistently demonstrated across patient subgroups.