Interferon beta in multiple sclerosis: experience in a British specialist multiple sclerosis centre

Abstract

Background: The efficacy of interferon beta (IFN beta) is well established in relapsing-remitting multiple sclerosis (MS). However, the use of this drug in clinical practice is complex, especially because it is only partially effective, its long term efficacy and side effects are unknown, its efficacy may be abrogated by the development of neutralising antibodies, compliance is variable, and its cost effectiveness is controversial. Objectives and Methods: Analysis of a prospectively followed up series of 101 MS patients treated with IFN beta was undertaken to: (1) monitor the outcome of IFN beta treatment in clinical practice; (2) compare the immunogenicity of the three commercial IFN beta preparations available; (3) assess the proportion of patients fulfilling the current guidelines of the Association of British Neurologists for stopping IFN beta therapy. Results: During a median treatment period of 26 months (range 2-85), the relapse rate decreased by 41%. Although the reduction in the relapse rate was similar for all three commercial products, none of the Avonex treated patients were relapse free, compared with 19% of the Betaferon treated and 27% of the Rebif treated patients (p=0.02). Neutralising antibodies were not detected in Avonex treated patients (0 of 18), compared with 12 of 32 (38%) Betaferon treated and 10 of 23 (44%) Rebif treated patients (p=0.02). Forty of 101 (40%) patients satisfied the current (2001) Association of British Neurologists criteria for stopping IFN beta treatment at some stage during their treatment. Conclusion: IFN beta is effective in reducing the relapse rate in patients with relapsing-remitting MS in routine clinical practice. However, after a median treatment duration of 26 months, 40% of initially relapsing-remitting MS patients seem to have ongoing disease activity, presenting as disabling relapses or insidious progression.T hree large, multicentre, randomised, double blind, placebo controlled trials have demonstrated that interferon beta (IFN beta) reduces the relapse rate in patients with relapsing-remitting multipe sclerosis (MS) 1-3 and in two of these studies IFN beta slowed the rate of accumulation of disability.2 3 One of the questions that has not been answered by these trials, is for how long IFN beta treatment should continue. This issue is important, not only to prevent unnecessary treatment, but to allow patients access to other potentially efficacious therapies and to enable health authorities to plan drug provision for MS.This prospective audit describes the implementation of IFN beta therapy at a tertiary referral centre, the National Hospital for Neurology and Neurosurgery (NHNN) in London. The unblinded, observational concept carries a number of inherent limitations, such as drug selection criteria, potential unblinding effects, and patient selection criteria.The aims of the audit were therefore (1) to evaluate the efficacy of IFN beta treatment in clinical practice; (2) to establish the immunogenicity of the different products and correlate the occurre...

Interferon-β_1b in Multiple Sclerosis: Effect on Progression of Disability and Clinical Markers of Treatment Response

“…These results were similar to those given in other published series [15, 19]. The reduced annualized relapse rate (0.78 in the pivotal trial versus our 0.7) in our series was similar to previously reported figures [2, 15, 19, 20]. …”

Beta-Interferon Treatment Reduces Human Herpesvirus-6 Viral Load in Multiple Sclerosis Relapses but Not in Remission

“…Beta-interferon (IFN-β), an approved treatment for MS, is an antiviral and an immunomodulatory cytokine that may modify the clinical course of the disease, specially in relapsing-remitting MS (RRMS) patients with acute demyelinating events [1, 2, 3, 4]in the following way: reduction in the 3-year cumulative probability of developing clinically definite MS, significant reduction of new T2 lesions, gadolinium-enhanced lesions and T2 lesion volume, reduction of tissue damage and promotion of lesion recovery in RRMS patients, and effective in reducing the relapse rate in patients with RRMS in routine clinical practice, i.e. change from baseline in mean number of exacerbations and proportion of exacerbation-free patients; however, we do not completely know what immunomodulatory mechanisms may be involved in the mediation of its positive effects in the treatment of MS patients, although it has been suggested that its antiviral properties contribute to its efficacy.…”

Nephrotic Syndrome in a Multiple Sclerosis Patient Treated with Interferon β1a

“…A 24hr protein collection quantitated proteinuria at 21.54 gm/24hr and creatinine clearance of 94 ml/min. Urinalysis showed 30 WBCs/cm 3 , 20 RBCs and no casts. Urine protein electrophoresis showed unselective protein loss.…”

“…2,3 Three preparations are available. Interferon β1b is distributed as Betaseron in North America and Betaferon in Europe and the Middle East.…”