Initial results from the longest study ever of a multiple sclerosis medication have been unveiled at a recent medical conference.1 The ongoing trial is testing the efficacy of Betaseron (interferon beta 1b) in a group of more than 200 patients over a 16-year follow up period.
The initial findings were presented at an annual meeting of the American Academy of Neurology, held in early April.
Follow-Up of Original Study Patients
The results of a Betaseron pivotal trial in the late 1980s led to the approval of the drug in 1993 for the treatment of relapsing-remitting multiple sclerosis. This is the most common form of the disease characterized by episodes of acute worsening of symptoms followed by partial or complete recovery periods free of MS progression.2
People who first enrolled in the Betaseron pivotal trial between 1988 and 1990 are being followed in this latest study. Investigators began contacting these patients earlier this year and so far, 234 have been identified. The 16-year follow-up study is expected to be completed later this year.
How the Initial Trial Was Carried Out
In that original trial—the first randomized, controlled trial of a medication made for multiple sclerosis—patients were selected at random to one of three groups. The first group received 50 microgram (mcg) doses of the medication, the second group was given 250 mcg doses, and the last group received a placebo as a comparison. The trial lasted for up to 4 years. It was later found that the 250 mcg dose was more effective than the lower one.
Analysis after two years showed that significantly more patients receiving Betaseron were relapse-free, that the relapses that did occur were less severe, and that hospitalizations for MS were cut nearly in half.
Latest Findings
So far, in the 16-year follow-up period, patients who received the 250-mcg dose have been more likely to report continued walking ability without assistance, the study researchers claim. The preliminary data show that about 50 percent of those in that group reported the ability to walk without assistance compared to 41 percent of those originally assigned to the group receiving a placebo.
In terms of mortality, nearly 90 percent of the 234 patients identified from the Betaseron pivotal trial are still alive. When broken down by the group to which the patients were originally assigned, 94 percent of those given the 250 mcg doses of Betaseron are still alive, the investigators reported. That compares to 82 percent of those in the placebo group.
More Study Needed: Expert
“The differences between the original treatments groups in the preliminary data warrant further investigation,” said George Ebers, MD, a professor of Neurology at the University of Western Ontario in London, Ontario, and one of the follow-up study’s investigators. “It is important to determine if the treatment benefits seen in the first years of the Betaseron pivotal trial confer long-term benefits, as these preliminary results might suggest.”
Ebers says this is the first study to evaluate the impact of treating patients with disease-modifying interferons in terms of long-term disability and life expectancy. While MS usually doesn’t pose a high risk of death, he said, previous studies have suggested that there’s a modest reduction in life expectancy for people with the disease.
The 16-year follow up study will also help doctors determine the long-term safety and efficacy when medication for MS is initiated early on in the course of the disease, the study authors noted.
“I anticipate that the full study results will help us to better judge the question of long-term effectiveness,” Ebers said. “In addition, the full results will provide us with data we do not have at this preliminary stage around the measurement of cognitive function, including memory, attention, and reasoning.”
1. Ebers G, Rice G, Wolf C et al. 16-year long-term follow-up of interferon beta-1b treatment in RRMS. 57th Annual Meeting of the American Academy of Neurology. 2005 Apr 9-16. Miami Beach, FL.
2. National Multiple Sclerosis Society. What is Multiple Sclerosis? Available at: http://www.nationalmssociety.org/What%20is%20MS.asp. Accessed May 16, 2005.
John Martin is a long-time health journalist and an editor for Priority Healthcare. His credits include overseeing health news coverage for the website of Fox Television's The Health Network, and articles for the New York Post and other consumer and trade publications.
