Plegridy® (peginterferon beta-1a)
FDA-Approved Medications: New Data on Previously Approved Medications
- Dose: 125 mcg every 14 days, selfadministered subcutaneously (starting at 63 mcg at Day 1, then increasing to 94 mcg on Day 15 and to 125 mcg on Day 29)
- Approved for RMS in 2014
Plegridy® (peginterferon beta-1a) is a synthetic version of the human interferon beta. Interferon beta slows progression of MS by balancing the expression of pro- and anti inflammatory substances in the brain and preventing some inflammatory neurons from crossing into the brain. This reduces neuron inflammation and is believed to increase production of nerve growth factor.
Plegridy gained FDA approval in 2014 for relapsing forms of MS (RMS). The pivotal double-blind study followed 1,012 individuals with RMS who had a baseline Expanded Disability Status Scale (EDSS) score of 5.0 or less and who had experienced at least two relapses within the previous three years and at least one relapse in the previous year. The participants were randomized to Plegridy 125 mcg or placebo once every 14 days. Neurological evaluations were performed at baseline, every 12 weeks, and during a suspected relapse. Brain MRI evaluations were done at baseline, week 24, and week 48.
At 48 weeks, the mean number of T1-enhancing lesions was significantly lower in the Plegridy group than among placebotreated patients (0.2 versus 1.4), as was the mean number of T2 new or enlarging hyperintense lesions (3.6 versus 10.9). Relapse rates also were significantly reduced among individuals receiving Plegridy, compared with placebo.42
New Phase IV (post-approval) data suggest Plegridy slows MS-related disability with long-term use. Researchers studied 963 patients who received at least one dose of the medication. The individuals were split into two groups: newly diagnosed (242) and nonnewly diagnosed (721). More than 80 percent of the participants with either newly diagnosed or long-standing RMS remained relapse-free for up to two years.
Nearly one-third of the individuals in both groups discontinued Plegridy at some point after initiation. Adverse events and lack of effect were the most commonly cited reasons for discontinuation, and influenza-like illness and injection-site irritation were the most commonly reported adverse effects.14