Interferon beta (IFNβ) was the first disease-modifying
therapy available to treat
multiple sclerosis (MS), providing patients with a treatment that resulted in reduced relapse rates and delays in the onset of disability. Four IFNβ drugs are currently approved to treat relapsing forms of MS: subcutaneous (SC) IFNβ-1b, SC IFNβ-1a, intramuscular IFNβ-1a, and, most recently, SC
peginterferon beta-1a.
Peginterferon beta-1a has an extended half-life and requires less frequent administration than other available treatments (once every 2 weeks vs every other day, 3 times per week, or weekly). Large randomized controlled clinical trials have confirmed the efficacy of
interferons for the treatment of relapsing MS. The most frequent adverse events in patients receiving IFNs include
injection site reactions and flu-like symptoms. Patient education and mitigation strategies are key to managing these adverse events and supporting
therapy adherence. With fewer
injections needed,
peginterferon beta-1a is associated with less frequent discomfort, which may translate to improved adherence, a major factor in treatment efficacy. Because the available
interferon therapies differ in administration route and frequency of injection, switching among these
therapies may be a viable option for patients who experience issues with tolerability. Although a variety of disease-modifying
therapies are now available to treat relapsing MS, the efficacy and long-term safety profile of
interferons make them an important first-line option for treatment.