Baumhefner told MedPage Today that standard practice for experiencing breakthrough disease on interferon treatment is to switch them to another drug. Eighteen drugs have been approved for the treatment of MS, but around half became available within the past decade.
"The long-term side effects of these newer agents are not known, so it might be advantageous to keep many of these patients -- if they stabilize -- on a drug that has been proven to be safe for 25 years," Baumhefner said.
Several previous studies, including the PRISMS trial, have suggested a dose-response effect for IFN-β in the treatment of MS, but other studies have failed to show this. Baumhefner noted that prior studies have not addressed the strategy of doubling the IFN dosage and treatment schedule for IFN-treated patients with breakthrough disease.
A total of 107 MS patients were started on intramuscular IFNβ-1a at the MS clinic of the VA West Los Angeles Medical Center from 1995 to 2015, and 59 of these patients with breakthrough disease were switched to twice-weekly intramuscular IFNβ-1a. Fifty-two patients were followed for at least 2 years.