Interferon β-1b shows sustained benefits in multiple sclerosis (MS) even after 11 years of treatment, with patients who start the drug early continuing to have a significant edge over those who had delayed treatment, new research finds.
“Many believed there might be a loss of benefit over time (with interferon β-1b treatment), but we consistently saw that the delayed treatment group never ‘caught up’ with the patients treated earlier,” coauthor Mark S. Freedman, MD, a professor of medicine (neurology) with the University of Ottawa and Ottawa Research Center, in Ontario, Canada, told Medscape Medical News.
The BENEFIT (Betaferon/Betaseron in newly emerging multiple sclerosis for initial treatment) trial originally involved 468 patients randomly assigned to subcutaneous interferon β-1b, 250 μg (n = 292; early treatment), or placebo (n = 176; delayed treatment) subcutaneously every other day for 2 years, or until diagnosis of clinically definite MS.
All patients had a first event suggestive of MS and two or more MRI lesions suggestive of MS at the study’s baseline.
After 2 years or the conversion to clinically definite MS, patients in the placebo group were offered treatment with interferon β-1b or other treatments. Those who switched to interferon β-1b represented the delayed treatment group in subsequent studies, with a mean delay in treatment initiation of 1.33 years.
For the 11-year follow-up, presented here at the American Neurological Association (ANA) 2014 Annual Meeting, 278 of the original 468 patients were enrolled, including 167 from the early treatment group and 111 from the delayed treatment group.
The patients in the early treatment groups continued to show favorable outcomes at 11 years, including a longer time to development of clinically definite MS compared with the delayed treatment group (P=.0012) and a lower estimate of risk for MS (65.2% vs 75% in the delayed treatment group; P=.0034).
Patients in the early treatment group also showed a longer period to a first relapse (P=.0005), and a 34.5% reduction in relapses compared to the delayed treatment group.
Similarly, the risk for secondary progressive MS at 11 years was twice as high in the delayed treatment group (8.3%) as in the early treatment group (4.5%).
“The low level conversion to secondary-progressive MS is expected, but the fact that two times as many patients did this transition from the delayed treatment group again plays on the suggestion that what is lost by not starting treatment immediately is never regained,” Dr Freedman said.
The annualized relapse rate was lower in the early treatment group (P=.0018) and the median Expanded Disability Status Scale (EDSS) remained low in both groups, with a median change of 0.5 for early and delayed treatment.
The long-term data showed that both groups fared relatively well, however. As many as 69.8% of patients in the combined study groups were fully ambulatory at 11 years, with minimal or no signs of disability, and an EDSS score of less than 3.0.
In addition, 73.4% of the patients continued to hold jobs, compared with 81.3% 11 years earlier.
The ability to continue employment with MS is especially notable, Dr Freedman said.
“The fact that patients remained ’employable’ indicates a benefit to society, as many patients have disease that make them seek disability insurance and they leave their jobs,” he said.
Neurologist Lily Jung-Henson, MD, medical director of Swedish Neuroscience Neurology at Ballard, in Seattle, Washington, agreed that the employability issue is an important benefit of MS treatment.
“The fact that early treatment resulted in low disability and the ability to remain employed helps frame discussions around cost-benefit,” Dr Jung-Henson told Medscape Medical News.
“Some payors argue that the cost of treatment may not be worth the potential benefit of treating the disease. However, if a patient is able to stay employed and therefore contribute to the overall economy, rather than becoming disabled, then it makes sense to treat early.”
In general, the reduction in the rate of disease progression with early treatment also represents an important benefit, Dr Jung-Henson said.
“Given the fact that 50% of patients progress at 15 years to impaired ambulation, the ability to reduce the rate of progression translates into better functioning long-term, again important in a condition that doesn’t significantly reduce life span and affects people in the prime of their lives.”
The study received support from Bayer Schering Pharma. Dr Freedman has served as a director, officer, partner, employee, advisor, consultant, or trustee for Actelion Pharmaceuticals, Ltd; Bayer HealthCare Pharmaceuticals; Biogen Idec Inc; Celgene Corporation; EMD Serono Inc; Glycominds; Genzyme; Merck Serono; Novartis Pharmaceuticals Corporation; Opexa; and sanofi-aventis. He has received research grant from Bayer HealthCare Pharmaceuticals and Genzyme Corporation. Dr Jung-Henson speaks on behalf of Serono and Pfizer, which makes Rebif (interferon β-1b); Novartis, which makes Extavia (also interferon β-1a); and Biogen, which makes Avonex and Plegridy (interferon β-1a). She also receives consulting fees from Teva, Biogen, Novartis, and Genzyme and research funding from Biogen, Novartis, and Genzyme.