Merck & Co’s – known as MSD outside the US and Canada – Prevymis (letermovir) demonstrated non-inferior efficacy and a more favourable safety profile compared to standard of care valganciclovir in a phase 3 cytomegalovirus (CMV) disease prevention trial in adult patients following kidney transplantations.
The findings from the trial were presented during a late-breaking oral session at the IDWeek Annual Meeting and will form the basis of a supplemental new drug application to the US Food and Drug Administration (FDA) by the end of the year, the company said in a statement.
At 52 weeks following kidney transplant, trial results met the primary endpoint of demonstrating that the anti-viral agent was effective and non-inferior to valganciclovir for preventing CMV disease, with 10.4% of participants who received Prevymis developing CMV disease versus 11.8% of participants on valganciclovir.
Moreover, in a pre-specified safety analysis, Prevymis treated participants had significantly less myelotoxicity, as measured by rates of leukopenia or neutropenia, compared to valganciclovir-treated participants; 26.0% versus 64.0%.
CMV is a common herpes virus, infecting a large proportion of the population. Those with normal immune systems rarely develop CMV symptoms after initial infection, with the virus typically remaining inactive or latent in the body for life.
Transplant patients, however, are among those most vulnerable to CMV infection, especially in the critical few months after the transplant, which can lead to end-organ damage, including gastrointestinal tract disease, pneumonia or retinitis.
“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,” explained Dr Ajit 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, but with significantly less toxicity,” Limaye added.
Also commenting on the positive results of the study, Dr Nicholas Kartsonis, senior vice president, vaccines and infectious diseases, global clinical development, Merck Research Laboratories, said: “There is a need for additional CMV prophylactic options for kidney transplant recipients to help patients reduce risk of opportunistic infections.
“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.”