The follow-up to a pivotal clinical trial of a currently available multiple sclerosis (MS) therapy is about to wind to a close at nearly a dozen trial sites around the country. It's the longest follow-up of a clinical trial involving Betaseron (interferon beta-1b), spanning nearly two decades. The latest results from the follow-up trial were released in late September at a meeting of neurologists in San Diego.1
Patient Outcomes Assessed After 16 Years
Investigators have been making contact with patients who took part in the original Betaseron pivotal clinical trial, conducted between 1988 and 1990. That study led to the approval of the medication in 1993. It was the first, large, randomized, placebo-controlled study of any therapy in MS. Betaseron also became the first medication to treat relapsing MS at that time.
So far, 331 of the original 372 patients who had taken part in the pivotal trial have been identified.
In the original study, patients were selected at random to receive one of two doses of Betaseron: 50 micrograms (mcg) or 250 mcg, the current prescribed dosage of the drug. A third group of patients was assigned randomly to a group receiving only a placebo.
On average, patients continued on the three interventions for nearly four years. Two years later, doctors learned that significantly more patients who had received either of the two doses of Betaseron had no MS relapses compared to those on a placebo. Those that did experience a relapse found it was less severe. The number of hospitalizations also dropped among those who had been taking the medication. The same results were confirmed five years later, according to Betaseron's manufacturer, Berlex.
After the pivotal study was completed, the drug was made available to all patients.
Positive Results Noted
"I am impressed by the fact that even after 16 years, the investigators in this study were able to identify nearly 90 percent of the patients from the original trial in a short period of time," said George Ebers, MD, lead investigator in the 16-year follow-up trial, and a professor in the Department of Clinical Neurology at Oxford University. "This is important because results from follow-up studies with retention rates higher than 80% can be viewed with greater confidence."
Earlier this year, Ebers and his colleagues released earlier findings from the follow-up trial at meeting of the American Academy of Neurology.2
So far, 51 percent of patients who received the 250-mcg dose have been more likely to report continued walking ability without assistance compared to 45 percent of those who had taken a placebo initially, the study researchers claim. Additionally, nearly all of the patients originally assigned to receive 250 mcg of Betaseron are still alive today, compared to about 83 percent of those who had received a placebo in the pivotal trial.
Review of the patient data is expected to continue into next year. Final results are expected to be unveiled at that time.
"We look forward to the completion of the Betaseron 16-Year Long-Term Follow-Up Study," said Ralph Makar, Vice-President and General Manager of the Therapeutics Business Unit at Berlex Labs, in a statement. "The results of this study will provide valuable information regarding the potential impact of early treatment initiation and the long-term safety, efficacy, and tolerability of Betaseron."
1. 130th Annual Meeting of the American Neurological Association. 2005 Sep 25-28. San Diego, CA.
2. 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.
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.
