Plegridy® (peginterferon beta-1a)

FDA-Approved Medications: New Data on Previously Approved Medications: Injectable Medications

Company: Biogen

  • Dose: 125 micrograms injected subcutaneously every 14 days
  • Approved in 2014 for relapsing forms of MS

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Plegridy is a form of interferon beta-1a that is pegylated, meaning that its chemical structure allows for longer duration of the medication’s effect. Like other interferon-based agents used in multiple sclerosis, however, the exact means by which Plegridy exercises its therapeutic effect in MS is not fully understood.

An evaluation of the long-term safety and effectiveness of Plegridy in adults with relapsing forms of MS has yielded reassuring findings, researchers reported recently.

The Plegridy Observational Program (POP) is an initiative sponsored by Biogen, the company that markets Plegridy. It is a five-year project involving patients in 14 countries who are taking Plegridy. The effort is a “post-marketing study,” meaning that it collects data on real-world use of a medication following the medication’s approval by regulatory authorities.

The study includes a safety analysis involving 1,126 patients, plus an effectiveness analysis that examines data on 1,125 patients. Results for both analyses are grouped according to whether individuals are newly diagnosed (those diagnosed with MS within one year before consenting to the study) and those who were previously diagnosed. The newly diagnosed individuals are younger (mean age 38.0 vs 45.9 years), have less MS-related disability, and have a higher rate of relapse before entering the study (mean relapses: 0.9 vs 0.3) than those diagnosed more than one year before entering the study.

As of September 11, 2018, annualized relapse rates were similar between the newly and previously diagnosed patients (0.12 vs 0.14). Serious adverse events were reported in 5.3% of those who were newly diagnosed, compared with 7.0% of previously diagnosed individuals. Transient, post-injection flu-like symptoms were common in both groups (reported in 47.7% of newly diagnosed and 38.6% of previously diagnosed patients) as were injection-site reactions (35.8% vs 38.6%). Of note, newly diagnosed individuals had a significantly shorter MS-treatment history (mean duration 21.5 months), compared with non-newly diagnosed individuals (mean duration 87.3 months).

No birth defects, premature births, or ectopic or molar pregnancies relating to Plegridy exposure were reported among expectant mothers in the study. Nineteen live births and two miscarriages were recorded.55

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