Incidence of exacerbations in the first 90 days of treatment with recombinant human interferon beta-1b in patients with relapsing-remitting multiple sclerosis

Multiple sclerosis disease-modifying therapies: adverse effect surveillance and management

There are five approved, partially effective, parenteral disease-modifying therapies for multiple sclerosis (MS), including three interferon-beta preparations, glatiramer acetate and the antineoplastic agent mitoxantrone. A sixth drug, natalizumab, was withdrawn from the market in 2005 but could return with increased safety measures. Careful surveillance for, and management of, the minor and serious adverse effects associated with these therapies in routine practice provides the best opportunity for maintaining compliance and achieving maximal therapeutic efficacy. This review outlines the strategies for the prevention, identification and management of the complications associated with administration and ongoing use of current MS therapies. These skills will become increasingly important to those caring for MS patients as contemporary treatment regimens become increasingly complex.

A role for interferon-beta in Guillain-Barré Syndrome?

Guillain-Barré syndrome (GBS) is an acute inflammatory demyelinating neuropathy that is associated with long-lasting morbidity and a substantial risk of mortality. The 2 reference treatments, plasma exchange and intravenous immunoglobulins (IVIg), do not change the functional prognosis for the most severely ill patients. The pathogenesis of GBS involves humoral and cellular immune dysfunctions that have only recently been characterised. Antibodies to nerve antigens may participate in complement activation, antibody-dependent macrophage cytotoxicity and reversible conduction failure. The cellular immune reaction is associated with increases in pro-inflammatory cytokines [such as tumour necrosis factor-alpha (TNFalpha)] and matrix metalloproteinases (MMPs; e.g. MMP-9), and a decrease in anti-inflammatory cytokines [such as transforming growth factor-beta1 (TGFbeta1)]. All the changes favour adhesion to and transmigration across the endothelium of immune cells, a key phenomenon associated with GBS. Recovery from GBS is characterised by the normalisation of these changes. Experimental allergic neuritis (EAN), the experimental model of GBS, has strikingly similar immunological characteristics. The usual treatment options for patients with GBS (plasma exchange and IVIg) mainly target the humoral component of the immune response. Interferon-beta (IFNbeta) is a cellular immunomodulator that inhibits antigen presentation and TNFalpha production and binding, and modulates macrophage properties. IFNbeta increases anti-inflammatory T cell functions and the production of anti-inflammatory cytokines, such as TGFbeta1. IFNbeta has important effects on leukodiapedesis, caused by modulating the expression of cell adhesion molecules and the MMP-9 proteinases. It has been used with success in EAN, in some patients with acute exacerbation of chronic inflammatory demyelinating polyneuropathy, and in 1 patient with GBS. The pathophysiology of patients with GBS, an understanding of IFNbeta properties and results of experimental studies support the investigation of IFNbeta in trials of patients with GBS.

[Trial of rituximab in three patients with neuromyelitis optica]

Patients with relapsing neuromyelitis optica (NMO) showing contiguous long spinal cord lesions extending over three vertebral segments on the MRI and with positive anti-aquaporin 4 antibodies in sera are usually treated with glucocorticoids or azathioprine. However, some NMO patients even after adequate treatments show relapses. Rituximab (anti-CD 20) therapy has recently been reported to inhibit relapses. We used rituximab to treat three NMO patients defined by the revised NMO criteria of Wingerchuk et al, with rituximab for 2 years and 3 months (mean) at an intervals of about nine months. The annualized relapse rate for the 3 patients during the year before rituximab therapy was 4, 5, and 6, respectively, and this decreased to 3, 1, and 0 in the year after therapy. Case 1 showed three relapses after therapy: however, the symptoms and signs of each of the relapses were milder and the patient showed good responses to steroid pulse therapy. One year after therapy, relapses had disappeared in all cases (observation periods; 18, 18, and 9 months, respectively). After rituximab therapy, these NMO patients showed a decreased mean annualized relapse rate (from 5.0 to 0.6) and EDSS score (from 8.7 to 8.0) after rituximab therapy. No adverse effects were seen. We recommend rituximab therapy for NMO patients resistant to other immunosuppressive therapies such as oral glucocorticoid administration introduced after a severe relapse. However, during long term rituximab treatment, attention needs to be given to infections such as progressive multifocal leucoencephalopathy.

Early relapse in multiple sclerosis-associated optic neuritis following the use of interferon beta-1a in Chinese patients

PURPOSE

The incidence of multiple sclerosis (MS) is relatively rare in Chinese. The beneficial effect of interferon beta-1a in modifying the disease course of MS has been rarely analyzed in Chinese patients. The aim of this study was to investigate the clinical response to interferon beta1-a in Chinese patients with MS-associated optic neuritis (ON).

METHODS

A retrospective case control study was conducted in 20 MS patients with optic nerve involvement. The interferon (IF) group comprised ten patients receiving interferon beta-1a. The noninterferon (NIF) group comprised another ten MS patients with optic nerve involvement who did not receive interferon treatment. The clinical characteristics, laboratory data, management, and disease course were retrospectively analyzed. The main outcomes of the study were the annualized relapse rate (ARR) for MS, and final visual outcome data.

RESULTS

The ARR did not differ between the pretreatment period and the posttreatment period within the IF group. There was also no significant decrease of ARR in the IF group when compared with the NIF group. However, we observed an early recurrence of ON in 50% of the IF cases following the use of interferon beta-1a. The final visual outcome did not differ between the IF group and the NIF group.

CONCLUSIONS

The use of interferon beta-1a should be carefully monitored because early relapse of ON may complicate the treatment course in this patient group.

Effects of interferon-β on the cytokine production of astrocytes

The effects of interferon (IFN)-beta used for treatment of multiple sclerosis (MS) on the central nervous system (CNS) have not yet been elucidated. The effect of IFN-beta and IFN-gamma on astrocytes as the major component of the CNS was investigated using murine primary astrocytes and human astrocytoma U251 cell line. IL-1beta, IL-6, TNF-alpha and iNOS were analyzed by RT-PCR. Both protein and mRNA levels of IL-6 were increased by IFN-beta. IFN-gamma augmented the effect of IFN-beta on IL-6 production. These results suggest that IFN-beta has an activity to modulate inflammatory and immune responses by up-regulating IL-6 in the CNS of MS.

Time-dependent cytokine deviation toward the Th2 side in Japanese multiple sclerosis patients with interferon beta-1b

To address the immune mechanism sustaining interferon beta (IFNbeta) efficacy in multiple sclerosis (MS), we longitudinally analyzed expressions of IFN-gamma, IL-4, IL-5 and IL-13 in CD4+ T cells and CD8+ T cells in 22 Japanese MS patients (16 patients with conventional MS and 6 with opticospinal MS) undergoing IFNbeta using flow cytometry. During the 48-week observation period, five opticospinal MS patients (83%) relapsed compared to only four conventional MS patients (25%); the frequency of relapsed patients was significantly higher in the former (p=0.046). The effects of IFNbeta on individual cytokines were time-dependent and altered cytokine productions were particularly evident in CD4+ rather than CD8+ T cells. A decreased intracellular IFN-gamma/IL-4 ratio in CD4+ T cells was thus evident soon after the initiation of therapy, and persisted for the entire 1 year follow-up period, regardless of whether or not the patient relapsed (p<0.01). IFNbeta treatment resulted in a rapid increase in the percentage of IFN-gamma- IL-4+ and IL-13+ CD4+ T cells 1 week after the initiation of therapy and high values were sustained for 6 months but declined to the baseline over 1 year. Later, the percentage of IFN-gamma+ IL-4- CD4+ T cells decreased significantly from weeks 24 through 48 of therapy (p<0.01). When comparisons with the pretreatment values were made for each subtype of MS, a significant reduction of IFN-gamma+ IL-4- CD4+ T cell percentages was shown in conventional MS (p<0.0001), but not in opticospinal MS. Moreover, when such a comparison was made by the presence or absence of relapse during therapy, a significant reduction of IFN-gamma+ IL-4- CD4+ T cell percentages was observed in MS patients without relapse (p<0.01). Thus, a reduction of IFN-gamma+ IL-4- CD4+ T cell percentages in the late phase of therapy is considered important for reducing relapse in conventional MS. When the expression patterns of IFN-gamma, IL-4, IL-5 and IL-13 in CD4+ T cells and CD8+ T cells were compared between patients with and without relapse during therapy, the only significant difference was an increase in the IL-13+ CD4+ T cell percentages in patients with relapse compared to those without (p<0.05). The results indicate that in CD4+ T cells IL-4 was preferentially up-regulated in the early course and IFN-gamma was down-regulated in the late phase of IFNbeta therapy. The net effect of IFNbeta on the immune balance was entirely toward type 2 immune deviation, possibly contributing to its beneficial effects on MS.

High-dose, frequently administered interferon beta therapy for relapsing–remitting multiple sclerosis must be maintained over the long term: the interferon beta dose-reduction study

Long-term trials have demonstrated the continued efficacy of interferon (IFN) beta treatment in patients with relapsing-remitting (RR) multiple sclerosis (MS) during prolonged administration. The objective of the work was to evaluate the effects of reducing IFN beta administration frequency and total weekly dose in patients with RR MS who have achieved clinical and MRI disease activity stabilization during long-term IFN beta-1b treatment. Prospective 1-year follow-up of 27 RR MS patients on long-term 250 microg every other day (standard dose) IFN beta-1b treatment were randomized either to gradually reduce dose to 30 microg once-a-week IFN beta-1a (13 patients), or to continue on IFN beta-1b standard dose (14 patients). We found significant differences in the two group of patients. In the group of patients continuously treated with IFN beta-1b standard dose, 79% remained relapse free compared to 23% in the group receiving once-weekly IFN beta-1a (p=0.006). The number of patients without new PD/T2 lesions was higher in the group of patients continuously treated with IFN beta-1b standard dose (77%) compared to the once-weekly IFN beta-1a group (23%) (p=0.04). IFN beta is a long-term treatment for MS. The reduction of IFN beta-1b administration frequency and dose is not advisable even in patients free from clinical and MRI disease activity for many years.

Disease-modifying therapy in multiple sclerosis: strategies for optimizing management

BACKGROUND

The objective for this article is to highlight several challenges faced by patients and providers in the utilization of disease-modifying agent (DMA) therapy in multiple sclerosis (MS) and to offer practical management strategies that can effectively mitigate or even prevent limiting adverse reactions and enhance treatment compliance.

REVIEW SUMMARY

Our discussion will be limited to the use of interferon beta1a (Avonex, Rebif), interferon beta1b (Betaseron), and glatiramer acetate (Copoxane) as these are the primary agents used in the United States for primary disease-modifying therapy in relapsing forms of MS. Some of the recommendations contained herein are derived from evidence-based studies, while others are contingent upon our collective clinical experiences. At the University of Texas Southwestern Medical Center at Dallas and Texas Neurology in Dallas we actively follow approximately 5000 MS patients. The majority of our patients with relapsing-remitting MS (RRMS) or secondary progressive MS (SPMS) are treated with one of the currently available DMAs. Our experience with these patients, and the challenges they face in continuing long-term treatment, constitutes the basis of our proposed treatment strategies. As part of this effort we formulated an assessment and intervention instrument that can be used in the clinic and by telephone to enhance compliance and minimize adverse events.

CONCLUSION

A comprehensive treatment approach to the utilization of disease-modifying therapy in MS can serve to optimize the management of our patients and effectively meet the challenges that arise during the course of treatment.

A prospective, open-label treatment trial to compare the effect of IFN beta-1a (Avonex), IFNbeta-1b (Betaseron), and glatiramer acetate (Copaxone) on the relapse rate in relapsing-remitting multiple sclerosis

A prospective, non-randomized, open-label treatment trial was performed in patients with relapsing-remitting multiple sclerosis (RRMS), with follow up for 12 months. Our primary objective was to prospectively compare the effect of IFNbeta-1a (Avonex), IFNbeta-1b (Betaseron), and glatiramer acetate (GA, Copaxone) on the relapse rate in patients with RRMS. Between August 1996 and September 1999, 156 consecutive patients with clinically definite RRMS with a Kurtzke scale (EDSS) score of 4 or less were followed for 12 months, from the time of initiating therapy or electing to remain untreated. Prior 2-year relapse history and available chart information was carefully reviewed at the time of enrolment. Thirty-three of 156 elected no treatment (mean age 32.5 years; mean EDSS 2.64) at enrolment; 40 elected IFNbeta-1a (mean age 32.4 years; mean EDSS 2.69), 41 IFNbeta-1b (mean age 32.1 years; mean EDSS 2.56), and 42 chose GA (mean age 31.5 years; mean EDSS 2.57). Annual relapse rate based upon the 2 years prior to enrolment was 1.08 in the untreated group, 1.20 in the AV group, 1.21 in the BE group, and 1.10 in the GA group. There were no statistically significant differences among the four groups at enrolment. After 12 months of treatment, patients in the untreated groups had a relapse rate of 0.97, whereas patients in the IFNbeta-1a, IFNbeta-1b, and GA groups had relapse rate of 0.85, 0.61, and 0.62, respectively. Compared to the untreated group, reduction in the relapse rate was statistically significant only in the GA (P=0.003) and IFNbeta-1b (P=0.002) groups, in contrast to the IFNbeta-1a treated patients, who did not show a significant reduction (P=0.309). Compared to the untreated patients, mean EDSS was significantly reduced only in the GA (P=0.001) and IFNbeta-1b (P=0.01), in contrast to IFNbeta-1a treated patients (P=0.51). In this prospective, controlled, open-label, non-randomized 12-month study, treatment with only GA and IFNbeta-1b significantly reduced the relapse rate compared to untreated patients, supporting early treatment in RRMS. Our results are similar to the observations made after 12 months of therapy in phase III studies of IFNbeta-1a, IFNbeta-1b, and GA. Despite some limitations of the study design, the results provide helpful clinical information regarding the relative efficacy of each therapy in mildly affected treatment-naïve RRMS patients.

Does high-dose interferon beta-1b improve clinical response in more severely disabled multiple sclerosis patients?

Prospective clinical open label follow-up of 52 multiple sclerosis patients treated with interferon beta-1b. After 18 months of treatment at standard 8 million international units (MIU) dose, subcutaneously on alternate days, IFNB dose was increased to 12 MIU in ten clinically non-responder patients. Eighteen months after, mean exacerbation rate, number and severity of exacerbations and number of patients with exacerbations or requiring corticosteroid treatment significantly improved, becoming similar to those of IFNB responders, always treated with 8 MIU. Baseline EDSS score of non-responders was higher than that of responders. Frequency and severity of adverse events were trending higher and dropout frequency higher in 12 MIU IFNB-treated patients.

Treatment of multiple sclerosis: recent trials and future perspectives

In the past year, further evidence establishing the usefulness of beta interferons and glatiramer in the treatment of relapsing-remitting multiple sclerosis has been advanced. Interferon-beta-1b was also shown to be efficacious in secondary progressive multiple sclerosis. This and other trials of symptomatic treatments are reviewed. Based on an appraisal of recent experimental studies, future promising approaches to intervene in the chain of immunopathogenetic events are discussed.