NASHVILLE -- Among multiple sclerosis (MS) patients experiencing breakthrough disease on standard-dose once-a-week interferon beta 1-a (IFN-1α), switching to twice-weekly dosing may offer advantages, a researcher reported here.
More than half of patients with breakthrough disease and adequate follow-up (26/52 patients) who were switched to twice-weekly treatment had no further clinical relapses, new T2 lesions, or enhanced lesions on MRI, or worsening of Expanded Disability Status Scale (EDSS) during at least 14 months (range 14 to 192 months) of follow-up, according to Robert Baumhefner, MD, of the VA Greater Los Angeles Healthcare System.
Action Points
- Note that this study was published as an abstract and presented at a conference. These data and conclusions should be considered to be preliminary until published in a peer-reviewed journal.
He presented data on a 17-year experience treating MS patients with the twice-weekly dosage of intramuscular IFNβ-1a at the Consortium of Multiple Sclerosis Centers (CMSC) annual meeting.
Baumhefner told ľֱ 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 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.
Patients were evaluated, on average, every 4 months. At each visit an interval history of any relapse, Incapacity Status Scale, Functional Systems Scale, Expanded Disability Status Scale (EDSS), and a proprietary graded neurologic examinations were obtained.
Annual MRI of the brain using a contrast-enhanced MS protocol was also obtained for most patients.
Breakthrough disease was defined as continued clinical relapses, new T2 or enhanced lesions on MRI, or worsening of EDSS or neurologic examination.
Five patients did not tolerate the increase in frequency of administration. IFNβ neutralizing antibody testing was performed on 25 patients while on twice-weekly dosing, and one patient who failed twice-weekly IFNβ had consistently elevated titers on two determinations (4%).
African-American patients, patients with a higher EDSS score when switching, and patients with a longer duration of stability on once-weekly treatment were less likely to respond.
Baumhefner said for many patients with breakthrough disease on standard IFNβ-1a, increasing the treatment dosage with twice-weekly therapy may be an acceptable alternative to switching treatments.
June Halper, MSN, MSCN, CMCS CEO, agreed, noting that "it makes a lot of sense for some patients to stay on a drug that has worked for them, and tweak the therapy if there is a breakthrough instead of automatically moving on to another drug," she told ľֱ.
Baumhefner said a prospective, blinded, randomized trial comparing once-weekly and twice-weekly intramuscular IFNβ-1a may be warranted.
Disclosures
Baumhefner disclosed no relevant relationships with industry.
Primary Source
Consortium of Multiple Sclerosis Centers
Baumhefner RW "17-Year experience of treating multiple sclerosis with intramuscular interferon beta-1a twice a week" CMSC 2018; Abstract DX04.