Large Study Shows That Presence of Neutralizing Antibodies Did Not Predict Clinical Response to Betaseron Treatment
02 April 2007
Berlex, Inc., a U.S. affiliate of Bayer Schering Pharma AG, Germany, announced today the results of a retrospective study demonstrating that the presence of neutralizing antibodies (NAbs) that can develop in response to Betaseron(R) (interferon beta-1b) therapy did not predict clinical response in patients with multiple sclerosis (MS). (1) The study looked at data from over 6,600 patients across three continents. It is the largest dataset ever analysed on the relevance of NAbs to interferon beta therapy. The results were published in the March issue of The Journal of International Medical Research.
"This study confirms that NAbs, which develop in response to Betaseron therapy, tend to disappear over time and provides important evidence that the presence of NAbs in these patient populations was not associated with a poor clinical response to treatment." said Dr. Douglas Goodin, lead author of the article and Professor of Neurology, University of California, San Francisco. "While it is unclear how these findings might apply to other beta interferon therapies, these data underscore the fact that decisions regarding Betaseron treatment should be based on the clinical circumstances of the individual patient and not solely on the basis of their NAb status."
NAbs are antibodies that may attach themselves to an injected protein drug, such as beta interferon therapy, thereby potentially inhibiting its biological activity. All immunomodulating therapies for MS may cause the development of NAbs in a varying portion of patients, but there is controversy in the medical community about the role NAbs may or may not play in a patient's response to therapy.
"This study reinforces expert recommendations that treatment decisions should be based on a patient's overall response to therapy and not on the actual or potential presence of neutralizing antibiodies," said Darlene Jody, M.D., Executive Vice President, Specialised Therapeutics, Bayer Schering Pharma AG, Germany. "When treating MS, especially from the first event, patients and prescribers can continue to rely on the proven efficacy and safety of Betaseron."
The published study addressed the clinical impact of NAbs to Betaseron therapy in an office-based or "real world" setting. These results are in line with the clinical practice guidelines recently published by the American Academy of Neurology. (2) Since the development of NAbs is specific to each medication, it is unclear how these findings for Betaseron might apply to other beta interferons.
About the Study
The study reviewed the NAb status of 6,698 Betaseron patients from North America (n=2010), Europe (n=2417) and Australia (n=2271) using the myxovirus protein A assay (MxA). The prevalence of persistently high neutralizing antibodies in the Australian cohort, which included patients regardless of clinical response to Betaseron, was 37%. This finding was similar to the reported incidence seen in Betaseron clinical trials. The incidence of persistently high NAbs in the European and North American groups, however, was only 28% and 21% respectively even those these patients were pre-classified as having a "poor clinical response" to therapy. Since the patients known to be poor responders were more often NAb negative than the general population, the study concluded that persistent, high NAb status was not a key predictor of clinical response to therapy.
Data for the study were collected during a six-year period (1996-2002). Most of the NAb testing (73%) was performed within the first three years of treatment, when patients are thought to be at the greatest risk of developing NAbs. Patients in the study had MS for an average seven to 10 years at the time of testing.
(1) Goodin, DS, Hurwitz B, Noronha A.. Neutralizing Antibodies to Interferon beta-1b are Not Associated with Disease Worsening in Multiple Sclerosis. J Int Med Res. 2007; 35: 173-187.
(2) Goodin DS et al. Neutralizing antibodies to interferon beta: Assessment of their clinical and radiographic impact: An evidence report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology. Neurology 2007; 68: 977-984.
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