4 January 2018 - Shire today announced that the U.S. FDA) has granted breakthrough therapy designation for maribavir (SHP620), a Phase 3 investigational treatment for cytomegalovirus infection and disease in transplant patients resistant or refractory to prior therapy. 

By targeting a key CMV enzyme, maribavir is thought to inhibit cytomegalovirus (CMV) DNA replication and encapsidation, and prevent the escape of viral capsids from the nucleids of infected cells.

Breakthrough therapy designation status for maribavir was granted based on the data from two Phase 2 studies, including a Phase 2 trial in 120 patients ages 12 or older with CMV infection. In the study, 67% of patients treated with varying doses of maribavir (400 to 1200 mg twice daily) for up to 24 weeks had no detectable levels of the virus in their blood plasma within six weeks of starting treatment. Dysgeusia (taste disturbance) was the most commonly reported treatment-emergent adverse event (AE) considered to be related to maribavir. Other related treatment-emergent AEs occurring in greater than or equal to 5% of study participants for any dose included nausea, CMV infection, immunosuppressant drug level increased, diarrhoea, rash, vomiting, anaemia, and pruritus.

Read Shire press release