Enhanced Benefit of Increasing Interferon Beta-1a Dose and Frequency in Relapsing Multiple Sclerosis

Interferon-beta treatment for multiple sclerosis

Multiple sclerosis (MS) is the leading nontraumatic cause of neurologic disability in young adults. Interferon-beta, approved for use in 1993, was the first treatment to modify the course and prognosis of the disease and remains a mainstay of MS treatment. Numerous large-scale clinical trials in early, active patient populations have established the clinical efficacy of interferon-beta in reducing relapses and delaying disability progression. Although its mechanism of action remains incompletely understood, a reduction in active lesions seen on magnetic resonance imaging implies primary anti-inflammatory properties, a mechanism supported by basic immunologic research. Variation in individual patient responsiveness to interferon-beta may be due to disease variability or differential induction of interferon-stimulated genes. The magnitude of the therapeutic effect appears to be similar among products, but the optimal dose, route, and frequency of administration of the drug remain uncertain.

Fortschritte im Verständnis von Pathogenese und Immuntherapie der Multiplen Sklerose

In this article recent advances in research on the pathogenesis of multiple sclerosis (MS) are summarized. New evidence from molecular histopathology is discussed focussing on neurodegenerative aspects. In addition findings with a direct effect on therapeutic decisions are presented which have contributed to improved immunotherapy. During the last decade important advances in immunotherapy have proven especially useful for patients with relapsing-remitting MS. Escalating algorithms are available for both relapses and long-term immunotherapy. Novel therapeutic approaches with monoclonal antibodies have increasing importance, yet side effects are not completely understood. The pathogenetic insights presented here may open new avenues for novel immunotherapies and lead to individualized MS therapy in the future. Limitations are given for primary progressive MS due to the lack of suitable tissue specimens and experimental models. Neuroprotective treatment strategies aiming at the protection of glial and neuronal cells are still in early stages of development.

An exploratory study on interferon beta dose effect in reducing size of enhancing lesions in multiple sclerosis

Sixty-two patients with multiple sclerosis (MS) were imaged monthly over a six-month (ie, seven monthly magnetic resonance images [MRI]) natural history period (NHP). Thereafter, patients were randomized to receive 11 or 33 mug of subcutaneously injected interferon beta 1a (IFNp-1 a) with imaging monthly for nine months and at months 12, 18 and 24 of therapy phase (TP). In the present exploratory post hoc analysis, the authors evaluated IFNbeta-1a dose effect on reducing the size of contrast-enhancing lesions (CELs). MRIs performed at months 0, 3 and 6 of NHP and at months 3, 6, 9, 18 and 24 of TP were analysed. While a significant reduction in mean number of CELs was observed in both treatment groups of patients, the mean total volume and size of CELs was reduced only in patients undergoing therapy with 33 mug of IFNbeta-1a. The latter suggests a significant dose effect exerted by IFNbeta-1a in the evolution of CELs' dimensions during therapy.

Immunmodulatorische Stufentherapie der Multiplen Sklerose

The updated recommendations presented here reflect new developments in the diagnostic work-up and immunotherapy of multiple sclerosis (MS) as well as optimization of medical care for MS patients. Monoclonal antibodies provide considerable improvement of treatment, but their use in basic therapy is restricted by their side effect profile. Thus, for the time being, natalizumab is only approved for monotherapy after basic treatment has failed or for rapidly progressive relapsing-remitting MS. In contrast, long-term data on recombinant beta-interferons and glatiramer acetate (Copaxone) show that even after several years no unexpected side effects occur and that a prolonged therapeutic effect can be assumed which correlates with the dose or frequency of treatment. Recently IFN-beta1b (Betaferon) was approved for prophylactic treatment after the first attack (clinically isolated syndrome, CIS). During treatment with beta-interferons, neutralizing antibodies can emerge with possible loss of effectivity. In contrast, antibodies play no role in treatment with glatiramer acetate. During or after therapy with mitoxantrone, serious side effects (cardiomyopathy, acute myeloid leukemia) appeared in 0.2-0.4% of cases. Plasmapheresis is limited to individual curative attempts in escalating therapy of a severe attack. According to the revised McDonald criteria, the diagnosis of MS can be made as early as the occurrence of the first attack (CIS). Recommendations for optimized care of MS patients are also new, thus implementing a resolution of the European Parliament.

Remediable shortcomings in applying clinical pharmacology to neurological practice

The application of the clinical pharmacological approach to prescribing antiepileptic drugs has enhanced the efficiency of the drug treatment of epilepsy considerably. However, it would be possible to take the approach further in relation to this disorder by applying it to the more recently introduced antiepileptic drugs, to specific epileptic seizure syndromes and to seizure disorders of different degrees of activity. Similarly, the approach could be applied to the drug treatment of migraine attacks, to migraine prophylactic therapy and to the treatments of multiple sclerosis and Parkinsonism, with reasonable expectations that it would enhance the therapy of these disorders.

Disease-modifying drugs for multiple sclerosis: current and future aspects

Multiple sclerosis (MS) is the most common inflammatory demyelinating disorder of the human CNS, affecting an estimated 2.5 million people in the world. Until the 1990s, treatment was mainly symptomatic, but a new era began with the introduction of disease-modifying therapy that seems to alter the natural course of MS. Current drugs include three interferons (IFNs): IFN-beta1a (Avonex intramuscular; Biogen, Cambridge, USA; Rebif subcutaneous; Serono, Geneva, Switzerland), IFN-beta1b (Betaseron subcutaneous; Schering, Berlin, Germany) and glatiramer acetate (Copaxone subcutaneous; Teva, Petach Tikva, Israel). Ongoing research targeting a variety of mechanisms and processes means there is much promise for the future treatment of MS.

Drug Insight: interferon treatment in multiple sclerosis

Multiple sclerosis (MS) is a chronic demyelinating disease of the CNS. Between 1987 and 1997, clinical trials of three preparations of recombinant interferon-beta were conducted in patients with MS, ushering in a new therapeutic era. These medications have demonstrable benefits and seem to be safe; they represent an important advance in MS treatment. All three formulations of interferon-beta had modest effects on relapses and short-term progression of disability, but the effects on MRI lesion parameters were more substantial. The benefits were greater in clinically isolated syndromes and relapsing-remitting MS than in secondary progressive MS. Although these drugs have been shown to be effective, however, their long-term impact on clinically relevant disability progression is uncertain, and there are many areas of controversy in the MS field regarding the use of these products. There is still a need for more effective treatments, which might include new agents or combination therapies.

Neutralising antibodies to IFN-β in patients with multiple sclerosis

The development of neutralising antibodies (NABs), or neutralising activity in the absence of NABs, is a potential complication of therapy with interferon (IFN)-beta for patients with multiple sclerosis, limiting therapeutic efficacy. Discontinuation of IFN-beta therapy in patients found to have sustained titres of NABs > 1:100 over an interval of 3 - 6 months has been recently proposed as a Level A recommendation. The extent to which NABs are causative, rather than an epiphenomenon, in determining drug failure has been a matter of numerous investigations and is still controversial. Thus, further studies are warranted for determining the role that NABs may play in reducing the response to the drug. In particular, the effects of NABs in reducing the efficacy of IFN-beta therapy beyond clinical relapse rate and lesion load on conventional imaging are not as yet fully understood.

Benefits of high-dose, high-frequency interferon beta-1a in relapsing-remitting multiple sclerosis are sustained to 16 months: final comparative results of the EVIDENCE trial

The EVIDENCE trial demonstrated that interferon (IFN) beta-1a, 44 mcg subcutaneously (sc) three times weekly (tiw) (Rebif), was significantly more effective than IFN beta-1a, 30 mcg intramuscularly (im) once weekly (qw) (Avonex), in reducing relapses and magnetic resonance imaging (MRI) activity in patients with relapsing-remitting multiple sclerosis at both 24 and 48 weeks of therapy. We now present final comparative data on these patients, showing that the superior efficacy of IFN beta-1a, 44mcg sc tiw, for relapse measures and MRI activity, compared with IFN beta-1a, 30mcg im qw, was sustained for at least 16 months. The development of antibodies to IFN was associated with reduced efficacy on MRI measures and fewer IFN-related adverse events, but did not have an impact on relapse outcomes.

Subcutaneous Recombinant Interferon-??-1a (Rebif??)

Subcutaneous recombinant interferon-beta-1a (Rebif) 22 or 44 microg three times weekly is a valuable option in the first-line treatment in patients with relapsing-remitting multiple sclerosis (RRMS). It has shown benefits on outcome measures related to relapses, progression of disability and magnetic resonance imaging (MRI) in clinical trials. A significant efficacy advantage for subcutaneous interferon-beta-1a three times weekly over intramuscular interferon-beta-1a 30 microg once weekly was shown at 24 and 48 weeks. The most common adverse events are generally mild and clinically manageable. Considering both direct and indirect comparative clinical trial data, an assessment suggests that subcutaneous interferon-beta-1a 44 microg three times weekly has the best benefit-to-risk values of the available disease-modifying drugs used to treat RRMS.