FDA Approves Plegridy (Peginterferon Beta-1a) for Treatment of Multiple Sclerosis
Relapses, disability progression, and brain lesions are reduced in phase III study
The FDA has given the nod to Plegridy (peginterferon beta-1a, Biogen Idec) for the treatment of patients with relapsing forms of multiple sclerosis (RMS).
Plegridy is the only pegylated beta interferon (IFN) approved for use in RMS. It is dosed once every 2 weeks and can be administered subcutaneously with the Plegridy pen (a new, ready-to-use autoinjector) or a prefilled syringe.
The FDA’s approval of Plegridy is based on results from the pivotal ADVANCE trial, which involved more than 1,500 patients with MS. ADVANCE was a 2-year, phase III, placebo-controlled (in year 1) study that evaluated the efficacy and safety of Plegridy administered subcutaneously. The analyses for all primary and secondary efficacy endpoints occurred at the end of year 1. After the first year, patients receiving placebo were treated with Plegridy for the duration of the study.
In the first year of the ADVANCE trial, Plegridy dosed once every 2 weeks significantly reduced the annualized relapse rate (ARR) by 36% compared with placebo (P = 0.0007). Plegridy also reduced the risk of 12-week confirmed disability progression, as measured by the Expanded Disability Status Scale, by 38% compared with placebo (P = 0.0383). Moreover, active treatment significantly reduced the number of new gadolinium-enhancing [Gd+] lesions by 86% (P < 0.0001) and reduced new or newly enlarging T2-hyperintense lesions by 67% (P < 0.0001) compared with placebo.
The most common adverse events included injection-site reactions, flu-like illness, fever, headache, muscle pain, chills, injection-site pain, weakness, injection-site itching, and joint pain.
The IFN beta-1a in Plegridy is pegylated to extend its half-life, thereby allowing a less-frequent dosing schedule. Pegylation prolongs the circulation time of the molecule in the body by increasing its size, stabilizes the molecule by improving its solubility, and shields the molecule from enzymes in the body that try to break it down into smaller particles.
The recommended dosage of Plegridy is 125 mcg injected subcutaneously every 14 days. Patients should start treatment with 63 mcg on day 1. On day 15, the dose is increased to 94 mcg, reaching the full dose of 125 mcg on day 29.
Severe hepatic injury, including hepatitis, autoimmune hepatitis, and rare cases of severe hepatic failure, have been reported with IFN beta. Elevated hepatic enzyme levels and hepatic injury have been observed with the use of Plegridy in clinical studies. Depression, suicidal ideation, and suicide have been reported in patients receiving IFN beta. Seizures are also associated with the use of IFN beta. Anaphylaxis and other serious allergic reactions are rare complications of treatment with IFN beta. Injection-site reactions, including injection-site necrosis, can occur with the use of subcutaneous IFN beta.
Congestive heart failure, cardiomyopathy, and cardiomyopathy with congestive heart failure can occur in patients receiving IFN beta. IFN beta can cause decreased peripheral blood counts in all cell lines, including rare instances of pancytopenia and severe thrombocytopenia. Autoimmune disorders of multiple target organs, including idiopathic thrombocytopenia, hyper- and hypothyroidism, and autoimmune hepatitis, have been reported with the use of IFN beta.