Merck, known as MSD outside the United States and Canada, announced that the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) has adopted a positive opinion recommending approval of Prevymis (letermovir) for prophylaxis of cytomegalovirus (CMV) reactivation and disease in adult CMV-seropositive recipients [R+] of an allogeneic haematopoietic stem cell transplant (HSCT).

The CHMP positive opinion will be considered by the European Commission. If the CHMP opinion is affirmed, the European Commission will grant a centralized marketing authorization with unified labeling that is valid in the 28 countries of the European Union (EU), as well as European Economic Area members, Iceland, Liechtenstein and Norway. Merck anticipates that the European Commission decision will be adopted within approximately two months.

In the pivotal phase 3 clinical trial evaluating letermovir, significantly fewer patients in the Prevymis arm (38%, n=122/325) compared to the placebo arm (61%, n=103/170) developed clinically significant CMV infection, discontinued treatment or had missing data through Week 24 post-HSCT [treatment difference: -23.5 (95% confidence interval -32.5 to -14.6), (p<0.0001)], the primary efficacy endpoint.

Prevymis was approved by the US Food and Drug Administration (FDA) on November 8. In the US, Prevymis is indicated for prophylaxis of cytomegalovirus infection and disease in adult CMV-seropositive recipients [R+] of an allogeneic hematopoietic stem cell transplant. Merck also has filed letermovir for regulatory approval in other markets including Japan, where it is currently under review.