Letermovir for preventing cytomegalovirus in children and adolescents following allogeneic haematopoietic stem cell transplant

Letermovir is being developed for the prevention of cytomegalovirus (CMV) in children and adolescents following allogeneic haematopoietic stem cell transplant (HSCT). CMV is a common virus that can cause mild infection. Most people get infected at some stage during their lifetime but are very often unaware of it. After infection, the virus remains in the body in a 'latent' (inactive) state and only becomes active again if the body's immunity, specifically its cell-mediated immunity, is weakened. CMV disease in patients with impaired cell-mediated immunity such as HSCT patients is long-term, debilitating, and life-threatening because of the complications it causes, such as inflammation of the lungs, liver, and the digestive tract. Prevention of CMV infection/disease in children after transplantation has been challenged by the limited number of available antivirals and side effects associated with currently available products.