Merck Announces Pivotal Phase 3 Study of Letermovir

Kenilworth : Merck & Co., Inc., known as MSD outside the United States and Canada, announced that the pivotal Phase 3 clinical study of letermovir, an investigational antiviral medicine, met its primary endpoint. The global, multicenter, randomized, placebo-controlled study evaluated the efficacy and safety of letermovir for the prevention of clinically-significant cytomegalo virus (CMV) infection in adult (18 years and older) CMV-seropositive recipients of an allogeneic hematopoietic stem cell transplant (HSCT). Merck will submit results from the study for presentation at a future scientific conference.

“There is an unmet need for therapeutic options in the prevention of CMV infection in high-risk allogeneic hematopoietic stem cell transplant recipients,” said Dr. Roy Baynes, senior vice president of clinical development, Merck Research Laboratories. “Merck is pleased this pivotal Phase 3 study with letermovir met its primary endpoint. We thank the patients and families who participated in this study and we look forward to presenting results at a future scientific meeting.”

In the study, letermovir was administered once daily, either in oral tablet or IV formulation. Letermovir was started as early as the day of HSCT transplant and no later than 28 days post-transplant, and continued through approximately 100 days after transplant. The primary outcome measure was the percentage of participants with clinically-significant CMV infection through 24 weeks after transplant.