The National Institute for Health and Care Excellence (NICE) has changed its mind and issued a Final Appraisal Document, recommending MSD’s Prevymis (letermovir) for preventing cytomegalovirus (CMV) reactivation and disease after an allogeneic haematopoietic stem cell transplant (HSCT) within the NHS.

HSCT - commonly known as blood or bone marrow transplants - can be a life-saving treatment for a range of different diseases including certain cancers such as leukaemia and lymphoma, but a typical HSCT regimen can weaken the immune system, allowing for the reactivation of CMV in infected individuals.

Prevymis is a member of a new class of drugs called non-nucleoside CMV inhibitors, which work by inhibiting the ability of the CMV virus to replicate within the body.

The recommendation is based on data from a Phase III clinical trial that included 565 patients who received stem cell transplants, and found that 24 weeks after the transplant a lower proportion of patients in the Prevymis group developed clinically significant CMV infection, compared to the placebo group.

Henny Braund, chief executive of Anthony Nolan, which manages a register of over 700,000 potential stem cell donors, said that the company are “delighted” that NICE has accepted the drug, in what is an “important step forward.”

He continued, “This decision may subsequently allow stem cell transplant patients in England, Wales and Northern Ireland access to a treatment which could significantly improve their quality of life. Recovering from a stem cell transplant can be a long road and letermovir may help patients avoid the most difficult side effects associated with other treatment options. We’re happy to see that NICE views patient experience so highly in their decision-making.”

In draft guidelines in July last year, NICE noted that while clinical trial evidence shows that Prevymis is indeed effective in reducing CMV infection and reduces the need for pre-emptive therapy, whether it reduces mortality from CMV disease is uncertain and rejected it.

Approximately 50-80% of adults in the UK are thought to be infected with CMV, which is a common member of the herpes family of viruses. Once infected it often persist in the body in an inactive or latent state, typically causing no symptoms.