Phase III trial of MK 8228 for Cytomegalovirus - Merck

Merck/MSD has announced that the first patient has been enrolled in a global Phase III clinical study of MK 8228 (letermovir), to evaluate 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 allogeneic hematopoietic stem cell transplants. In the study, letermovir will be administered once daily, either as an oral tablet or IV formulation, for 14 weeks after transplant. The dose will be 240 mg once daily for participants receiving concomitant cyclosporin A and 480 mg once daily for participants not receiving cyclosporin A.

The primary outcome measure of the study will be the percentage of participants with clinically-significant CMV infection through 24 weeks after transplant who were administered letermovir compared to placebo. Merck expects approximately 540 patients will be enrolled in the study at more than 70 centers in 20 countries, including the United States. The estimated study completion date is July 2017.