Plegridy: Just Approved. Interferon Every 2 weeks.

A new form of interferon beta-1a  (the active ingredient in Avonex and Rebif) is now available in a pegylated form.  A tail was added to the interferon molecule so injection under skin can be given only once every 2 weeks.

In the ADVANCE Trial,  512 patients received 125 micrograms of Plegridy and 500 patients received placebo every 14 days under the skin over 48 weeks.   MS attacks (annualized relapse rate) dropped by 36%.    Risk of disability progression was reduced by 38%.  Sixty-seven percent less new or enlarging T2 lesions and 86% less contrast-enhancing T1 lesions.

Risks of Plegridy are similar to other interferons and can include injection site reactions, flu-like symptoms, liver injury, depression and allergic reactions.  Plegridy comes in a single-dose prefilled pen or prefilled syringe.