A (Slightly) New Medication for Multiple Sclerosis Comes Out in November
October 21, 2014
Interferons have been used for the treatment of multiple sclerosis (MS) since 1993. The existing line-up of interferons for MS (Avonex, Betaseron, Extavia and Rebif) will soon be joined by Plegridy, approved by the US Food and Drug Administration in August 2014. Plegridy will become commercially available in November 2014.
Plegridy is a pegylated form of interferon beta. Pegylation is a process, used by several other non-MS medications, whereby a long string of polyethylene glycol molecules is attached to the interferon beta molecule, to extend its half-life by reducing clearance via kidneys or other elimination pathways in the body. This modification allows less frequent dosing of Plegridy – once every two weeks – although it is still administered as an injection under the skin.
In the ADVANCE trial, Plegridy was compared to placebo and demonstrated efficacy in reducing the relapses, MRI activity and disability progression. Both biweekly and monthly dosing were tested, but only the biweekly dosing was found to be effective. Plegridy exhibited similar tolerability and safety profile to that of other interferons, with about 60% patients reporting injection site redness, while 47% reported flu-like symptoms at any time (but only 5% of the patients in the study discontinued the treatment due to side effects). Because no head-to-head trials were done with Plegridy, it remains to be seen how Plegridy compares with the existing MS treatments in terms of efficacy. This information would be of particular significance to those MS patients currently on interferons who are looking for a more convenient form of therapy. The other unknown at this time is the cost of this medication.