A pivotal phase 3 study of letermovir (Merck), an investigational antiviral medication, has met its primary endpoint. The global, randomized, placebo-controlled trial evaluated the efficacy and safety of letermovir for the prevention of clinically significant cytomegalovirus (CMV) infection in adult (ages 18 years and older) CMV-seropositive recipients of an allogeneic hematopoietic stem-cell transplant (HSCT).
In the study, letermovir was administered once daily as either an oral tablet or an intravenous formulation. Treatment was started as early as the day of the HSCT transplant and no later than 28 days post-transplant, and was continued for approximately 100 days after transplant. The primary outcome measure was the percentage of participants with clinically significant CMV infection at 24 weeks after transplant.
Letermovir 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. The medication has been granted an orphan designation by the FDA for the prevention of CMV infection and disease in at-risk populations. Letermovir also has been granted fast track status.
Source: Merck; October 19, 2016.