Glatiramer acetate for the treatment of multiple sclerosis

Glatiramer acetate (Copaxone, Teva Pharmaceuticals Ltd) is a collection of immunomodulatory, synthetic polypeptides indicated for the treatment of relapsing-remitting multiple sclerosis (RR MS). Preclinical and clinical studies provide an evolving understanding of the mechanisms by which glatiramer acetate exerts both immunological and potential neuroprotective effects that account for its clinical efficacy. The results of pivotal controlled clinical trials and long-term data, derived from organised extension studies, are evaluated in detail and supportive data from open-label comparison, combination treatment and therapeutic switch studies are considered in order to determine the place of glatiramer acetate among other approved therapies for RR MS. The efficacy of glatiramer acetate is stable or may increase over time and the drug has a favourable side effect profile. Glatiramer acetate is an appropriate first-line immunomodulatory therapy for RR MS.

Neurologic consequence of delaying glatiramer acetate therapy for multiple sclerosis: 8-year data

OBJECTIVE

To assess the long-term effectiveness of continuous glatiramer acetate (GA) therapy in relapsing-remitting multiple sclerosis (RRMS).

METHODS

This open-label extension followed a randomized, placebo-controlled, double-blind study of GA of approximately 30 months duration. Patients originally randomized to GA continued on it (group A) and those randomized to placebo switched to GA (group B).

RESULTS

Of 251 original patients, 142 (56.6%) remained in the study after 8 years. Annual relapse rate for both groups declined to approximately 0.2 (approximately one relapse every 5 years). However, a significantly larger proportion of patients in group A had stable or improved Expanded Disability Status Scale scores compared with group B (65.3% vs 50.4%, respectively; P = 0.0263), possibly attributable to the delay of GA treatment for approximately 30 months in group B. GA was well tolerated and no drug-related laboratory changes were observed.

CONCLUSIONS

These data support early initiation of GA therapy as an efficacious and well-tolerated long-term treatment for RRMS patients.

Diffusion tensor fractional anisotropy of the normal-appearing seven segments of the corpus callosum in healthy adults and relapsing-remitting multiple sclerosis patients

PURPOSE

To investigate the utility of whole-brain diffusion tensor imaging (DTI) in elucidating the pathogenesis of multiple sclerosis (MS) using the normal-appearing white matter (NAWM) of the corpus callosum (CC) as a marker of occult disease activity.

MATERIALS AND METHODS

A high signal-to-noise ratio (SNR) and optimized entire brain DTI data were acquired in 26 clinically-definite relapsing and remitting multiple sclerosis (RRMS) patients and 32 age-matched healthy adult controls. The fractional anisotropy (FA) values of seven functionally distinct regions in the normal-appearing CC were compared between patients and controls.

RESULTS

This study indicates that 1) there was a gender-independent FA heterogeneity of the functionally specialized CC segments in normal volunteers; 2) FA in the MS group was significantly decreased in the anterior (P=0.0039) and posterior (P=0.0018) midbody subdivisions of the CC, possibly due to a reduction of small-caliber axons; and 3) the FA of the genu of the CC was relatively intact in the MS patients compared to the healthy age-matched controls (P=0.644), while the splenium showed an insignificant trend of reduced FA values (P=0.248). The decrease in FA in any of the CC subdivisions did not correlate with disease duration (DD) or the expanded disability status scale (EDSS) score.

CONCLUSION

The preliminary results are consistent with published histopathology and clinical studies on MS, but not with some published DTI reports. This study provides insights into the pathogenesis of MS, and the role played by compromised axonal integrity in this disease.

Magnetic resonance techniques for the in vivo assessment of multiple sclerosis pathology: Consensus report of the white matter study group

On October 9-11, 2003, the third meeting of the White Matter Study Group of the International Society for Magnetic Resonance in Medicine was held in Venice, Italy. This article is the report of the meeting on how to use MRI in the diagnostic workup of multiple sclerosis (MS) and allied white matter disorders, and to define the nature and the extent of MS pathology in vivo. Both of these steps are central to the design of future treatment strategies aimed at limiting the functional consequences of the most disabling aspects of this disease.

The PROMiSe trial: baseline data review and progress report

The PROMiSe trial is a multinational, multicentre, double-blind, placebo-controlled trial evaluating the effects of glatiramer acetate treatment over 3 years in patients with primary progressive multiple sclerosis (PPMS). A total of 943 patients were enrolled, and all those remaining on-study had completed at least 24 months as of October 2002. Baseline clinical and MRI characteristics and select correlations are reported here. A total of 3.9% of patients exhibited confirmed relapse over 1904 patient-years of exposure, indicating success of efforts to exclude relapsing MS types. Of the 26.3% of patients who have prematurely withdrawn from the study, only 36% discontinued after meeting the study primary endpoint of disease progression. The progression rate in patients in the low Expanded Disability Status Scale (EDSS) stratum (3.0-5.0) observed thus far is markedly lower than the 50% annual progression rate estimate used for determining size and statistical power of the trial; progression was observed in 16.1% of patients with 12 months of study exposure. These early findings raise some concern about the ability of the trial to demonstrate a significant treatment effect, and suggest that the short-term natural history of PPMS may not be as aggressive as previously assumed.

Multicentre proton magnetic resonance spectroscopy imaging of primary progressive multiple sclerosis

Multicentre baseline proton magnetic resonance spectroscopic data on primary progressive multiple sclerosis (PPMS) patients are acquired and analysed, using automatic analysis software. The metabolite ratios did not differ from centre to centre. The average N-acetylaspartate/creatine (NAA/Cr) ratio in PPMS was significantly lower compared to normal controls. No significant differences were observed in this ratio between lesion-containing regions (LCR) and normal-appearing tissues (NAT). Strong lipid resonances, even in the absence of lesions, are observed in the both grey and white matter in these patients. These observations suggest extensive diffuse and/or microscopic pathology in PPMS. No significant correlation between any of the metabolite ratios and the Extended Disability Scale Score (EDSS) or with other MR measures such as lesion burden and enhancement volumes is observed.

Measurement error of two different techniques for brain atrophy assessment in multiple sclerosis

The measurement errors associated with two techniques for brain atrophy assessment in multiple sclerosis (MS) were estimated. The measurement error of a semiautomated, nonnormalized technique with partial brain coverage was about twofold higher than that of a fully automated, normalized technique with full brain coverage (Structural Image Evaluation of Normalized Atrophy software [SIENA]). As shown by the analysis of data from a clinical trial of glatiramer acetate, the use of SIENA increases the study power to detect a treatment effect on brain volume changes in MS patients.

Glatiramer acetate (Copaxone): comparison of continuous versus delayed therapy in a six-year organized multiple sclerosis trial

The aim of this study was to assess the long-term safety and efficacy of glatiramer acetate (GA) for patients with multiple sclerosis (MS) who received active treatment versus those on placebo for approximately 30 months (24-35 months) before receiving GA during a six-year organized, prospective open label study. Entry required two relapses in the previous two years and an Expanded Disability Status Scale (EDSS) score of 0-5. Patients (251) were equally randomized to daily subcutaneous GA, 20 mg, or to placebo. After approximately 30 months, 208 patients continued in an open label study: 101 continued on GA and 107 switched from placebo to active drug. Groups were well matched at randomization and entry to the open label study. Patients always on GA showed a steady decline in relapses: a mean of 1.5 per year at entry, a mean of 0.42 over the entire six years (95% CI = 0.34-0.51), a 72% reduction (P = 0.0001). They averaged a relapse every four + years (yearly rate 0.23 in year six) and 26/101 remain relapse free. Patients did less well if on placebo for 30 months, but relapses then declined, and by year six the rates were similar. Of patients always on GA, 69% showed neurological improvement of > or = 1 EDSS steps or remained stable compared with 57% if GA treatment was delayed. Of relapse-free patients always on GA over six years, only three of 26 (11%) were worse by > or = 1 EDSS steps, whereas nine of 21 (43%) in the placebo/active group were worse (P < 0.03). Disability, measured every six months, showed that the group of patients always on GA was relatively stable over the six years, while the group who received placebo for the first two-and-a-half years did significantly less well. Daily injections of GA were well tolerated. This longest ever organized MS treatment trial shows that delaying therapy with GA increases the risk of neurologic disability, reinforcing the rationale for using GA as a first-line treatment early in the course of relapsing-remitting MS.

Effects of glatiramer acetate on relapse rate and accumulated disability in multiple sclerosis: meta-analysis of three double-blind, randomized, placebo-controlled clinical trials

Three randomized, double-blind, placebo-controlled trials have shown that glatiramer acetate (GA) is effective in reducing relapse rate in patients with relapsing-remitting (RR) multiple sclerosis (MS). Using raw data pooled from 540 patients, we performed a meta-analysis of these three trials, to investigate whether the extent of GA efficacy varies according to disease-related variables at study entry. Three regression models were developed to assess the efficacy of GA on the annualized relapse rate (primary outcome measure), on the total number of on-trial relapses and on the time to first relapse. We also explored the efficacy of GA on accumulated disability and the potential role of baseline clinical variables as predictors of relapse-rate variables and treatment efficacy. The mean adjusted annualized relapse rate on study was 1.14 in the pooled placebo-treated subjects and 0.82 in the pooled GA group (P = 0.004), indicating an average reduction in annualized relapse rate of 28%. About a one third reduction of the total number of on-trial relapses was also observed in patients receiving GA (P < 0.0001), who had a median time to the first relapse of 322 days versus a median time to the first relapse of 219 days seen in those receiving placebo (P = 0.01). A beneficial effect on accumulated disability was also found (risk ratio of 0.6; 95%; CI = 0.4-0.9; P = 0.02). The drug assignment (P = 0.004), baseline EDSS score (P = 0.02) and number of relapses during the two years prior to study entry (P = 0.002) were significant predictors of on-trial annualized relapse rate. No other demographic or clinical variable at baseline significantly influenced the treatment effect. This meta-analysis reaffirms the effectiveness of GA in reducing relapse rate and disability accumulation in RRMS, at a magnitude comparable to that of other available immunomodulating treatments. It also suggests that GA efficacy is not significantly influenced by the patients' clinical characteristics at the time of treatment initiation.

The diagnosis of primary progressive multiple sclerosis

Primary progressive multiple sclerosis (PPMS) is a rather unique form of the more common relapsing inflammatory demyelinative disease. The absence of attacks that typify relapsing forms of MS imposes special challenges for diagnosis, but also provides an opportunity to study the pathogenesis of the more progressive aspects of the disease process in isolation of confounding transient clinical events. In this review, recent advances in diagnostic approaches are considered in relationship to baseline data from a large multinational study designed to better characterize and treat this clinical phenotype. PPMS subjects with cerebral spinal fluid (CSF) findings consistent with intrathecal immunoglobulin production may have a more tissue destructive disease process than those whose CSF lacks evidence of a B-cell immunopathogenic disease component.

Short-term correlations between clinical and MR imaging findings in relapsing-remitting multiple sclerosis

BACKGROUND AND PURPOSE

Despite extensive use of MR imaging to provide markers of multiple sclerosis (MS) activity and accumulated disease burden, the magnitude of the relationship between clinical and MR findings is still debated. Using data from the European/Canadian glatiramer acetate (GA) trial, we investigated short-term correlations between clinical and MR measures of disease activity in patients with relapsing-remitting MS (RRMS).

METHODS

In a 9-month, double-blinded, placebo-controlled study, 239 patients with RRMS were randomly assigned to receive 20 mg GA (n = 119) or placebo (n = 120). Clinical assessment included monthly neurologic examinations with Expanded Disability Status Scale scoring and visits for symptoms suggestive of relapse. Dual-echo T2-weighted and pre- and postcontrast T1-weighted brain MR images were obtained at baseline and monthly during follow-up. Contrast-enhancing and new T2-hyperintense lesions were counted, and total T2-hyperintense and T1-hypointense lesion volumes were measured.

RESULTS

Significant univariate correlations were found between the number of relapses during the study period and the number of enhancing lesions at baseline (r = 0.25) and during follow-up (r = 0.30) in the study population as a whole. Multivariable analysis showed that two independent factors were more strongly correlated with relapse frequency: the number of relapses during the 2 years before entry and the number of on-trial enhancing lesions, in the whole study population and in the placebo group.

CONCLUSION

In RRMS, MR imaging measures of inflammatory activity are modestly but significantly correlated with the occurrence of clinical attacks over the short term. Clinical and MR imaging assessment can provide complementary outcome measures for RRMS trials.

Report of the Consensus Panel on the New International Panel Guidelines for Diagnosis of MS

The new international panel guidelines for diagnosis of multiple sclerosis (MS) raised a number of concerns regarding their use and application, particularly in relation to their impact on treatment issues and options. As a result, a consensus panel composed primarily of North American neurologists with inclusion of several members from the International Panel was convened in Fort Worth, Texas, November 30 to December 2, 2001, to discuss these concerns, resulting in the following consensus statement regarding the guidelines and their appropriate use. (Int J MS Care. 2002; 4: 170–173)

Copaxone's effect on MRI-monitored disease in relapsing MS is reproducible and sustained

All but 6% of the subjects with relapsing remitting MS who were randomly assigned to receive glatiramer acetate or placebo for the 9-month controlled phase of the European/Canadian MRI trial entered an open-label extension with quarterly clinical and MRI evaluations for another 9 months. There was a 54% reduction in the mean number of enhanced lesions for those converted from placebo to glatiramer acetate and an additional 24.6% reduction for those always on glatiramer acetate. Over the entire study the accumulated T2 disease burden was 34.2% less for those always on glatiramer acetate.

Magnetic resonance spectroscopy in multiple sclerosis: window into the diseased brain

Magnetic resonance spectroscopy provides noninvasive insight into the regional and global biochemical alterations that are concomitants of the dynamic processes that underlie the evolution of fundamental pathologic changes in multiple sclerosis. These include now well-recognized alterations of neuronal biochemical markers that accompany tissue destruction readily visualized by magnetic resonance imaging, but also dynamic changes in several metabolites that indicate pathological processes that precede the magnetic resonance imaging-defined lesion, or completely escape current high-resolution imaging.

Ingested IFN-alpha: results of a pilot study in relapsing-remitting MS

OBJECTIVE

To investigate whether ingested human recombinant interferon-alpha2a (IFN-alpha2a) was safe and whether treatment reduces the number of gadolinium-enhanced lesions on serial MRI in patients with active relapsing-remitting MS (RRMS).

METHODS

Entry criteria included clinically definite RRMS and one or more gadolinium-enhanced lesions on a screening MRI.

RESULTS

Of 80 patients screened, 33 were eligible and 30 patients were enrolled for treatment. Patients were randomized (10 per group) to placebo, 10,000 or 30,000 IU IFN-alpha2a ingested on alternate days for 9 months. They were examined clinically and with monthly cerebral MRI. Sample size projections were based on the assumption of a parenteral IFN-like effect, a 90% reduction of enhancing lesions evident within 1 month of the initiation of treatment in the active treatment groups sustained during the 9-month study as the primary outcome variable.

RESULTS

There was no significant effect on enhancing lesions. However, post hoc analysis suggested a possible treatment effect in the 10,000 IU group. By direct monthly comparison of placebo and 10,000 IU group in treatment month 5, there were 73% (p < 0.05) fewer enhancements in the 10,000 IU group than in the placebo group. There was a decrease of tumor necrosis factor-alpha protein secretion at months 4 and 5. Relapses and adverse events were not different among the treatment groups. Ingested IFN-alpha2a did not induce systemic anti-IFN-alpha antibodies.

CONCLUSIONS

This trial showed no benefit based on the primary outcome measure. Because changes were detected in immune response and post hoc analysis suggested that a smaller dose could have an effect, IFN-alpha may deserve further study.