VIROPHARMA RECEIVES ORPHAN DESIGNATION FOR ANTIVIRAL

ViroPharma announced that the FDA has granted orphan drug designation for maribavir for prevention of cytomegalovirus (CMV) viremia and disease in at-risk populations.

CMV is a member of the herpes virus group, which includes the viruses that cause chicken pox, mononucleosis, herpes labialis and herpes genitalis. Like other herpes viruses, CMV has the ability to remain dormant in the body for long periods of time. However, in immunocompromised individuals including cancer patients, HIV patients and transplant patients, and in children born with primary CMV infection, CMV can lead to serious disease or death.

"We have made excellent progress with maribavir over the last 12 months. We demonstrated in a Phase II clinical trial that the drug appears to be well tolerated with impressive anti-CMV activity in stem cell transplant patients, which has allowed us to initiate our international Phase III development program," Colin Broom, ViroPharma's chief scientific officer, said.

Maribavir is a potent and selective orally bioavailable antiviral drug with a unique mechanism of action against cytomegalovirus and a favorable early clinical safety profile. It is a member of a new class of drugs called benzimidazole ribosides. Unlike currently available anti-CMV agents that inhibit CMV DNA polymerase, maribavir inhibits viral DNA assembly and egress of viral capsids from the nucleus of infected cells. Maribavir is also active in vitro against strains of CMV that are resistant to commonly used anti-CMV drugs.