KENILWORTH, NJ, USA I October 19, 2016 I Merck & Co., Inc. (NYSE: MRK), known as MSD outside the United States and Canada, today 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 cytomegalovirus (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. Additional details about the study can be found online at www.clinicaltrials.gov/ct2/show/NCT02137772.

About letermovir

Letermovir is an investigational once-daily antiviral medicine under development for the prevention of CMV infection and disease. It is a member of a new class of non-nucleoside CMV inhibitors (3,4 dihydro-quinazolines) and inhibits viral replication by targeting the viral terminase complex. Letermovir has been granted orphan designation by the European Medicines Agency, the U.S. Food and Drug Administration (FDA) and the Japanese Ministry of Health, Labour and Welfare for the prevention of CMV infection and disease in at-risk populations. Letermovir also has been granted Fast Track designation by the FDA.

Under an agreement signed in 2012, Merck (through a subsidiary) purchased worldwide rights to develop and commercialize letermovir from AiCuris GmbH & Co KG (www.aicuris.com).

About Merck

For 125 years, Merck has been a global health care leader working to help the world be well. Merck is known as MSD outside the United States and Canada. Through our prescription medicines, vaccines, biologic therapies, and animal health products, we work with customers and operate in more than 140 countries to deliver innovative health solutions. We also demonstrate our commitment to increasing access to health care through far-reaching policies, programs and partnerships. For more information, visit www.merck.com and connect with us on Twitter, Facebook, YouTube and LinkedIn.

SOURCE: Merck