Conference Coverage

More Frequent Dosing of Interferon Beta-1a May Benefit Patients With MS With Breakthrough Disease

Twenty-six patients receiving twice-weekly treatment had no further breakthrough disease for 14 months or more.


 

NASHVILLE—Patients with multiple sclerosis (MS) with breakthrough disease may benefit from intramuscular interferon beta 1-a treatment twice per week, according to research described at the 2018 CMSC Annual Meeting. “Advantages to using an intramuscular interferon beta 1-a preparation include no skin reactions and a lower incidence of interferon neutralizing antibodies,” said Robert W. Baumhefner, MD, a neurologist at the Veteran Affairs West Los Angeles Medical Center.

Previous clinical trials have suggested a dose-response effect for interferon beta in MS. The European Interferon Beta-1a Dose Comparison Study, however, found no change in efficacy with just doubling the standard dose of intramuscular interferon beta-1a once per week. This may not be the same as increasing the frequency of intramuscular interferon administration, said Baumhefner. In addition, none of the previous studies have information on patients with breakthrough disease on standard-dose intramuscular interferon beta-1a switched to twice-weekly dosing.

Dr. Baumhefner conducted a retrospective observational study of patients MS with breakthrough disease receiving intramuscular interferon beta 1-a once per week who were switched to intramuscular interferon beta 1-a twice per week.

A total of 107 patients with MS were started on intramuscular interferon beta 1-a from 1995 to 2015 at the MS clinic of the VA West Los Angeles Medical Center. Of these, 59 patients with breakthrough disease were switched to twice-weekly intramuscular interferon beta-1a. There was adequate follow-up for at least two years for 52 of these patients. In addition, participants were followed up an average of every four months.

At each visit, an interval history of any relapse; scores on the Incapacity Status Scale, Functional Systems Scale, and Expanded Disability Status Scale (EDSS); and a proprietary graded neurologic examination were obtained. Annual MRI of the brain using a contrast-enhanced MS protocol was obtained in most patients. Baumhefner defined breakthrough disease as continued clinical relapses, new T2 or enhanced lesions on MRI, or worsening of EDSS or neurologic examination.

Of the 52 patients with adequate follow-up, 26 had no further breakthrough disease for 14 months or longer (range, 14-192 months). Five patients did not tolerate the increase in frequency of administration. Interferon beta neutralizing antibody testing was performed on 25 patients while they were receiving twice-weekly dosing. One patient who failed twice-weekly interferon beta had consistently elevated titers on two determinations (4%). African American patients, those with a higher EDSS score when switching, and patients with a longer duration of stability on weekly dosed treatment may be less likely to respond, the researcher concluded.

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