Merck’s letermovir hits Phase III target

Merck’s ($MRK) FDA fast-tracked antiviral letermovir has hit its primary endpoint in a Phase III test as the partners look to capitalize on Chimerix’s blowup.

The Phase III test was looking at the efficacy and safety of letermovir once daily, in both tab and IV form, for the prevention of clinically significant cytomegalovirus (CMV) infection in patients that are seropositive recipients of an allogeneic hematopoietic stem cell transplant.

Data were not posted, but these will come at a future scientific conference, according to the company. The primary outcome measure was the percentage of participants with clinically significant CMV infection through 24 weeks after transplant.

The med is designed to inhibit the human CMV viral terminase and the Big Pharma got hold of the drug under a deal signed back in 2012 when Merck bought the worldwide rights to develop and sell letermovir from Bayer spinout AiCuris.

This will be a boost for Merck, and comes after rival Chimerix saw a Phase III study flop for its antiviral brincidofovir last year.  

“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, SVP of clinical development, Merck Research Laboratories.

“Merck is pleased this pivotal Phase III 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.”