Plegridy as Intramuscular Injection for RRMS Approved in Europe

The European Commission (EC) has approved a new, intramuscular formulation of Plegridy (peginterferon beta-1a) to treat people with relapsing-remitting multiple sclerosis (RRMS).

This new mode of administration — in which Plegridy is directly injected into the muscle, rather than under the skin (subcutaneously) — does not compromise the therapy’s safety or effectiveness. Rather, this formulation might lower the incidence of injection site reactions, offering patients a reliable alternative to the therapy’s standard subcutaneous formulation.

“The availability of a new intramuscular route of administration offers individuals living with relapsing MS an additional choice of a platform therapy, combining the safety and efficacy of Plegridy, with the potential to significantly reduce injection site reactions,” Maha Radhakrishnan, MD, chief medical officer at Biogen, the developer of Plegridy, said in a press release.

Plegridy is an immunomodulatory medication that aims to lower the frequency of severe bouts of inflammation in the central nervous system (CNS; brain and spinal cord) due to the immune system wrongly targeting and attacking myelin (the fatty substance that isolates and protects nerve endings).

The medication is made up of a “pegylated” form of interferon beta-1a, a naturally produced protein that is known to control the balance between anti- and pro-inflammatory immune signals.

The “pegylated” version of interferon beta-1a found in Plegridy’s composition, in which the protein is attached to a compound called polyethylene glycol (PEG), increases the time it takes for the protein to be eliminated from the body. This allows for Plegridy to be administered less often, usually once every two weeks.

Plegridy’s original subcutaneous formulation was approved to treat relapsing MS in the U.S. and Europe in 2014, and it is currently available in more than 60 countries across the globe.

The therapy’s approval was supported by data from a Phase 3 trial, called ADVANCE (NCT00906399), which demonstrated Plegridy’s superiority over a placebo at lowering the number of relapses and MS lesions visible on MRI scans, as well as at slowing the rate of disability progression. Plegridy was also found to have a favorable safety and tolerability profile.

The EC’s decision to approve the new intramuscular formulation was based on data from an open-label Phase 1 trial showing this mode of administration was bioequivalent to Plegridy’s original subcutaneous formulation in healthy volunteers. Bioequivalence means that both formulations provide the same amount of the medication’s active ingredient at the expected site of action and at equivalent doses.

Both formulations were also found to have a similar safety profile. Although the frequency of side effects in volunteers given the medication by intramuscular or subcutaneous injections was identical (65.9% vs. 68.7%), the frequency of injection site reactions was lower in those receiving Plegridy’s intramuscular formulation (14.4% vs. 32.1%).

Biogen has also requested U.S. Food and Drug Administration approval of Plegridy as an intramuscular injection.