Merck, known as MSD outside of the United States and Canada, announced the presentation of findings from a Phase 3 clinical trial that assessed safety and efficacy of PREVYMIS (letermovir) compared to valganciclovir for cytomegalovirus (CMV) prophylaxis in 601 adult kidney transplant recipients at high risk for CMV disease (D+/R-).

At 52 weeks following kidney transplant, trial results met the primary endpoint demonstrating that PREVYMIS was effective and non-inferior to valganciclovir for preventing CMV disease. PREVYMIS is a first-in-class antiviral agent that was approved by the U.S. FDA in 2017 and is indicated for prophylaxis of CMV infection and disease in adult CMV-seropositive recipients [R+] of an allogeneic hematopoietic stem cell transplant (HSCT).

PREVYMIS is contraindicated in patients receiving pimozide or ergot alkaloids. Increased pimozide concentrations may lead to QT prolongation and torsades de pointes. Increased ergot alkaloids concentrations may lead to ergotism. PREVYMIS is contraindicated with pitavastatin and simvastatin when co-administered with cyclosporine. Significantly increased pitavastatin or simvastatin concentrations may lead to myopathy or rhabdomyolysis.

“CMV disease is an important cause of morbidity and mortality in kidney transplant recipients. Valganciclovir has been the most commonly used drug for CMV prophylaxis in this setting, but myelotoxicity (especially neutropenia and leukopenia) is an important limitation of this drug. Myelotoxicities can be difficult to manage in patients who are already receiving complex treatment regimens with other drugs that also have bone marrow suppressive effects,” said Dr. Ajit P. Limaye, Director, Solid Organ Transplant Infectious Disease Program at University of Washington School of Medicine.

“I was excited to see these trial results that showed that the efficacy of PREVYMIS for prevention of CMV disease in kidney transplant patients was similar to the current standard of care treatment (valganciclovir), but with significantly less toxicity.”

“There is a need for additional CMV prophylactic options for kidney transplant recipients to help patients reduce risk of opportunistic infections,” said Dr. Nicholas Kartsonis, senior vice president, vaccines and infectious diseases, Global Clinical Development, Merck Research Laboratories. “These new study results in adult kidney transplant patients are encouraging and demonstrate the potential of PREVYMIS to prevent CMV disease with a therapy that showed lower rates of neutropenia and leukopenia versus the comparator.”