Gender effects on intramuscular interferon beta-1a in relapsing-remitting multiple sclerosis: analysis of 1406 patients.

BACKGROUND: We aimed to evaluate effects of gender on efficacy and safety of intramuscular (IM) interferon beta (IFNß)-1a in patients with relapsing-remitting MS (RRMS) or clinically isolated syndromes (CIS) characteristic of early MS. METHODS: Pooled data from 1406 (1027 women; 379 men) patients enrolled in five clinical studies of IM IFNß-1a were analyzed. One analysis examined data for all patients treated with IM IFNß-1a from all studies. Separate analyses were conducted of pooled IM IFNß-1a-treated groups from all studies and pooled IFNß-1a-treated and placebo-treated patients from the placebo-controlled studies. Outcome measures included time to first relapse, annualized relapse rate, time to disability progression, number of gadolinium-enhanced lesions, adverse events, laboratory evaluations, and neutralizing antibodies. RESULTS: All efficacy assessments indicated similar treatment effects of IM IFNß-1a in men and women with no significant treatment-by-gender interactions. Women reported more headaches, urinary tract infections, and depression in the analysis; however, these were also common in women who received placebo. Men reported more frequent flu-like symptoms in the placebo-controlled studies only. There were no other differences in the safety profile of IM IFNß-1a between men and women. CONCLUSIONS: We conclude that no significant gender-related differences were found in the efficacy and safety of IM IFNß-1a in patients with RRMS or CIS.

Assessing disability progression with the Multiple Sclerosis Functional Composite.

BACKGROUND: The initial Multiple Sclerosis Functional Composite (MSFC) proposal was a three-part composite of quantitative measures of ambulation, upper extremity function, and cognitive function expressed as a single composite Z-score. However, the clinical meaning of an MSFC Z-score change is not obvious. This study instead used MSFC component data to define a patient-specific disease progression event. OBJECTIVE: Evaluate a new method for analyzing disability progression using the MSFC. METHODS: MSFC progression was defined as worsening from baseline on scores of at least one MSFC component by 20% (MSFC Progression-20) or 15% (MSFC Progression-15), sustained for >or=3 months. Progression rates were determined using data from natalizumab clinical studies (Natalizumab Safety and Efficacy in Relapsing Remitting Multiple Sclerosis [AFFIRM] and Safety and Efficacy of Natalizumab in Combination With Interferon Beta-1a in Patients With Relapsing Remitting Multiple Sclerosis [SENTINEL]). Correlations between MSFC progression and other clinical measures were determined, as was sensitivity to treatment effects. RESULTS: Substantial numbers of patients met MSFC progression criteria, with MSFC Progression-15 being more sensitive than MSFC Progression-20, at both 1 and 2 years. MSFC Progression-20 and MSFC Progression-15 were related significantly to Expanded Disability Status Scale (EDSS) score change, relapse rate, and the SF-36 Physical Component Summary (PCS) score change. MSFC Progression-20 and MSFC Progression-15 at 1 year were predictive of EDSS progression at 2 years. Both MSFC progression end points demonstrated treatment effects in AFFIRM, and results were replicated in SENTINEL. CONCLUSION: MSFC Progression-20 and MSFC Progression-15 are sensitive measures of disability progression; correlate with EDSS, relapse rates, and SF-36 PCS; and are capable of demonstrating therapeutic effects in randomized, controlled clinical studies.

Proof of concept studies for tissue-protective agents in multiple sclerosis.

BACKGROUND: There is considerable interest in tissue-protective treatments for multiple sclerosis (MS). METHODS AND OBJECTIVES: We convened a group of MS clinical trialists and related researchers to discuss designs for proof of concept studies utilizing currently available data and assessment methods. RESULTS: Our favored design was a randomized, double-blind, parallel-group study of active treatment versus placebo focusing on changes in brain volume from a post-baseline scan (3-6 months after starting treatment) to the final visit 1 year later. Study designs aimed at reducing residual deficits following acute exacerbations are less straightforward, depending greatly on the anticipated rapidity of treatment effect onset. CONCLUSIONS: The next step would be to perform one or more studies of potential tissue-protective agents with these designs in mind, creating the longitudinal data necessary to refine endpoint selection, eligibility criteria, and sample size estimates for future trials.

GLANCE: results of a phase 2, randomized, double-blind, placebo-controlled study.

OBJECTIVE: To evaluate the safety and tolerability of natalizumab when added to glatiramer acetate (GA) in patients with relapsing multiple sclerosis. The primary outcome assessed whether this combination would increase the rate of development of new active lesions on cranial MRI scans vs GA alone. METHODS: This phase 2, randomized, double-blind, placebo-controlled study included patients aged 19 to 55 years who were treated with GA for at least 1 year before randomization and experienced at least one relapse during the previous year. Patients received IV natalizumab 300 mg (n = 55) or placebo (n = 55) once every 4 weeks plus GA 20 mg subcutaneously once daily for < or = 20 weeks. RESULTS: The mean rate of development of new active lesions was 0.03 with combination therapy vs 0.11 with GA alone (p = 0.031). Combination therapy resulted in lower mean numbers of new gadolinium-enhancing lesions (0.6 vs 2.3 for GA alone, p = 0.020) and new/newly enlarging T2-hyperintense lesions (0.5 vs 1.3, p = 0.029). The incidence of infection and infusion reactions was similar in both groups; no hypersensitivity reactions were observed. One serious adverse event occurred with combination therapy (elective hip surgery). With the exception of an increase in anti-natalizumab antibodies with combination therapy, laboratory data were consistent with previous clinical studies of natalizumab alone. CONCLUSION: The combination of natalizumab and glatiramer acetate seemed safe and well tolerated during 6 months of therapy.

MRI outcomes in a placebo-controlled trial of natalizumab in relapsing MS.

BACKGROUND: In a 2-year, placebo-controlled trial (the Natalizumab Safety and Efficacy in Relapsing Remitting Multiple Sclerosis [AFFIRM] study), involving 942 patients with relapsing multiple sclerosis (MS), natalizumab significantly reduced the relapse rate by 68% and progression of sustained disability by 42% vs placebo. We report the effect of natalizumab on MRI measures from the AFFIRM study. METHODS: The number and volume of gadolinium (Gd)-enhancing, new or enlarging T2-hyperintense, and new T1-hypointense lesions and brain parenchymal fraction were measured from annual scans obtained at baseline, 1 year, and 2 years. RESULTS: Compared with placebo, natalizumab produced a 92% decrease in Gd-enhancing lesions (means 2.4 vs 0.2; p < 0.001), an 83% decrease in new or enlarging T2-hyperintense lesions (means 11.0 vs 1.9; p < 0.001), and a 76% decrease in new T1-hypointense lesions (means 4.6 vs 1.1; p < 0.001) over 2 years. Median T2-hyperintense lesion volume increased by 8.8% in the placebo group and decreased by 9.4% in the natalizumab group (p < 0.001); median T1-hypointense lesion volume decreased by 1.5% in the placebo group and decreased by 23.5% in the natalizumab group (p < 0.001). Brain atrophy was greater in year 1 and less in year 2 in natalizumab-treated patients. CONCLUSION: Natalizumab has a sustained effect in preventing the formation of new lesions in patients with relapsing multiple sclerosis.

Estimating long-term effects of disease-modifying drug therapy in multiple sclerosis patients.

Two methods were used to estimate the long-term impact of disease-modifying drug therapy (DMDT) in patients with relapsing multiple sclerosis (MS) who completed a placebo-controlled, randomized clinical trial of interferon beta-1a (IFNbeta-1a). The study cohort consisted of patients with ambulatory relapsing MS who had previously participated in a placebo-controlled clinical trial for two years. At its end, patients were managed in an unstructured fashion by their neurologists and re-evaluated at an average of 6.1 years after the end of the trial. Follow-up evaluation was obtained for 93% of the 172 eligible patients. Because study inclusion criteria required that all patients have an Expanded Disability Status Scale (EDSS) score of < or = 3.5 at entry, disability progression at follow-up was defined as EDSS > or = 6.0. Two methods were used to estimate the expected proportions that reached EDSS > or = 6.0 at follow-up. Estimates were compared with observed proportions. Method 1 used progression rates observed during the two-year phase III clinical trial and the percentage of time that patients were on DMDT during the follow-up period. Method 2 used progression rates from a natural history comparison group of relapsing-remitting MS patients. At the eight-year follow-up, 42.0% of the original placebo patients and 29.1% of the original IFNbeta-1a patients reached an EDSS > or = 6.0, an observed treatment effect of approximately 30%. Using method 1, it was estimated that 36.3% of the original placebo patients and 27.6% of the original IFNbeta-1a patients should have reached an EDSS > or = 6.0. Use of the natural history control group (method 2) predicted less plausible outcomes. Estimated proportions of patients reaching the endpoint were 63.3% for the original placebo group and 55.8% for the original IFNbeta-1a group. Treatment effect sizes of 75-90% would be required to match estimates from method 2 with the observed outcome. The paucity of data on the long-term treatment of patients with MS may be aided by applying these or similar methods to vigorously followed cohorts of patients.

Contrast letter acuity as a visual component for the Multiple Sclerosis Functional Composite.

BACKGROUND: Visual dysfunction is one of the most common causes of disability in multiple sclerosis (MS). The Multiple Sclerosis Functional Composite (MSFC), a new clinical trial outcome measure, does not currently include a test of visual function. OBJECTIVE: To examine contrast letter acuity as a candidate visual function test for the MSFC. METHODS: Binocular contrast letter acuity testing (Sloan charts) was performed in a subgroup of participants from the International Multiple Sclerosis Secondary Progressive Avonex Controlled Trial (IMPACT Substudy) and in MS patients and disease-free control subjects from a cross-sectional study of visual outcome measures (Multiple Sclerosis Vision Prospective cohort [MVP cohort]). High-contrast visual acuity was measured in both studies; MVP cohort participants underwent additional binocular testing for contrast sensitivity (Pelli-Robson chart), color vision (D-15 desaturated test), and visual field (Esterman test, Humphrey Field Analyzer II). RESULTS: Contrast letter acuity (Sloan charts, p < 0.0001, receiver operating characteristic curve analysis) and contrast sensitivity (Pelli-Robson chart, p = 0.003) best distinguished MS patients from disease-free control subjects in the MVP cohort. Correlations of Sloan chart scores with MSFC and Expanded Disability Statue Scale (EDSS) scores in both studies were significant and moderate in magnitude, demonstrating that Sloan chart scores reflect visual and neurologic dysfunction not entirely captured by the EDSS or MSFC. CONCLUSIONS: Among clinical measures, contrast letter acuity (Sloan charts) and contrast sensitivity (Pelli-Robson chart) demonstrate the greatest capacity to identify binocular visual dysfunction in MS. Sloan chart testing also captures unique aspects of neurologic dysfunction not captured by current EDSS or MSFC components, making it a strong candidate visual function test for the MSFC.

A randomized, double-blind, dose-comparison study of weekly interferon beta-1a in relapsing MS.

BACKGROUND: Interferon beta-1a (IFNbeta-1a; Avonex) is effective for the treatment of relapsing MS; however, the optimal dose of IFNbeta-1a is not known. OBJECTIVE: To determine whether IFNbeta-1a 60 micro g IM once weekly is more effective than IFNbeta-1a 30 micro g IM once weekly in reducing disability progression in relapsing MS. METHODS: In a double-blind, parallel-group, dose-comparison study, 802 patients with relapsing MS from 38 centers in Europe were randomized to IFNbeta-1a 30 micro g (n = 402) or 60 micro g (n = 400) IM once weekly for >/=36 months. The primary endpoint was disability progression, defined as time to a sustained increase of >/=1.0 point on the Expanded Disability Status Scale (EDSS) persisting for 6 months. Additional endpoints included relapses, MRI, safety, immunogenicity, and subgroup analyses of disability progression. RESULTS: Both groups showed equal rates of disability progression (hazard ratio, 0.96; 95% CI, 0.77 to 1.20; p = 0.73). In both groups the proportion of subjects with progression of disability by 36 months estimated from Kaplan-Meier curves was 37%. No dose effects were observed on any of the secondary clinical endpoints. Only one MRI measure at one time point, number of new or enlarging T2 lesions at month 36 compared with month 24, showed a difference favoring the 60- micro g dose. Both doses were well tolerated; however, slightly higher incidences of flulike symptoms and muscle weakness were observed in the 60- micro g group. The incidences of neutralizing antibodies (titers >/= 20) were 2.3% in the 30- micro g group and 5.8% in the 60- micro g group. CONCLUSION: There was no difference between IFNbeta-1a 30 micro g and 60 micro g IM in clinical or MRI measures.

Benefit of interferon beta-1a on MSFC progression in secondary progressive MS.

BACKGROUND: Interferon beta-1a (IFNbeta-1a, Avonex) is efficacious in relapsing forms of MS. Studies of other IFNbeta preparations in secondary progressive MS (SPMS) yielded conflicting results. This study was undertaken to determine whether IFNbeta-1a slowed disease progression in SP-MS. METHODS: A total of 436 subjects with SPMS and Expanded Disability Status Scale (EDSS) score 3.5 to 6.5 were randomized to receive IFNbeta-1a (60 micro g) or placebo by weekly intramuscular injection for 2 years. The primary outcome measure, used for the first time in a large-scale MS trial, was baseline to month 24 change in the MS Functional Composite (MSFC), comprising quantitative tests of ambulation (Timed 25-Foot Walk), arm function (Nine-Hole Peg Test [9HPT]), and cognition (Paced Auditory Serial Addition Test [PASAT]). RESULTS: Median MSFC Z-score change was reduced 40.4% in IFNbeta-1a subjects (-0.096 vs -0.161 in placebo subjects, p = 0.033), an effect driven mainly by the 9HPT and PASAT. There was no discernible benefit on the EDSS, which in this range principally reflects walking ability. IFNbeta-1a subjects had 33% fewer relapses (p = 0.008). There was significant benefit on eight of 11 MS Quality of Life Inventory subscales. New or enlarging T2-hyperintense brain MRI lesions and gadolinium-enhancing lesions were reduced at months 12 and 24 (both p < 0.001). IFNbeta-1a was well tolerated by the majority of subjects. Neutralizing antibodies developed in 3.3% of IFNbeta-1a-treated subjects. CONCLUSIONS: IFNbeta-1a demonstrated benefit on MSFC progression, relapses, quality of life, and MRI activity in SPMS.

Use of the multiple sclerosis functional composite as an outcome measure in a phase 3 clinical trial.

BACKGROUND: The Multiple Sclerosis Functional Composite (MSFC) is a multidimensional clinical outcome measure that includes quantitative tests of leg function/ambulation (Timed 25-Foot Walk), arm function (9-Hole Peg Test), and cognitive function (Paced Auditory Serial Addition Test). The MSFC is the primary outcome measure in the ongoing multinational phase 3 trial of interferon beta-1a (Avonex) in patients with secondary progressive MS. OBJECTIVE: To assess the practice effects, reliability, and validity of the MSFC clinical outcome measure. DESIGN: Examining technicians underwent formal training using standardized materials. The MSFC was performed according to a standardized protocol. The 436 patients enrolled in the International Multiple Sclerosis Secondary Progressive Avonex Controlled Trial underwent 3 prebaseline MSFC testing sessions before randomization. RESULTS: Practice effects were evident initially for the MSFC but stabilized by the fourth administration. The Paced Auditory Serial Addition Test demonstrated the most prominent practice effects. The reliability of the MSFC was excellent, with an intraclass correlation coefficient for session 3 (final prebaseline session) vs session 4 (baseline) of 0.90. The MSFC at baseline correlated moderately strongly with the Kurtzke Expanded Disability Status Scale. Among the MSFC components, the Timed 25-Foot Walk correlated most closely. Correlations among the 3 MSFC components were weak, suggesting they assess distinct aspects of neurologic function in patients with MS. CONCLUSIONS: The MSFC demonstrated excellent intrarater reliability in this multinational phase 3 trial. Three prebaseline testing sessions were sufficient to compensate for practice effects. The pattern of correlations among the MSFC, its components, and the Kurtzke Expanded Disability Status Scale supported the validity of the MSFC.

Intramuscular interferon beta-1a therapy initiated during a first demyelinating event in multiple sclerosis. CHAMPS Study Group.

BACKGROUND: Treatment with interferon beta has been shown to help patients with established multiple sclerosis, but it is not known whether initiating treatment at the time of a first clinical demyelinating event is of value. METHODS: We conducted a randomized, double-blind trial of 383 patients who had a first acute clinical demyelinating event (optic neuritis, incomplete transverse myelitis, or brain-stem or cerebellar syndrome) and evidence of prior subclinical demyelination on magnetic resonance imaging (MRI) of the brain. After initial treatment with corticosteroids, 193 patients were randomly assigned to receive weekly intramuscular injections of 30 microg of interferon beta-1a and 190 were assigned to receive weekly injections of placebo. The study end points were the development of clinically definite multiple sclerosis and changes in findings on MRI of the brain. The trial was stopped after a preplanned interim efficacy analysis. RESULTS: During three years of follow-up, the cumulative probability of the development of clinically definite multiple sclerosis was significantly lower in the interferon beta-1a group than in the placebo group (rate ratio, 0.56; 95 percent confidence interval, 0.38 to 0.81; P=0.002). As compared with the patients in the placebo group, patients in the interferon beta-1a group had a relative reduction in the volume of brain lesions (P<0.001), fewer new or enlarging lesions (P<0.001), and fewer gadolinium-enhancing lesions (P<0.001) at 18 months. CONCLUSIONS: Initiating treatment with interferon beta-1a at the time of a first demyelinating event is beneficial for patients with brain lesions on MRI that indicate a high risk of clinically definite multiple sclerosis.

Heterogeneity of subcellular localization and electrophoretic mobility of survival motor neuron (SMN) protein in mammalian neural cells and tissues.

Spinal muscular atrophy is caused by defects in the survival motor neuron (SMN) gene. To better understand the patterns of expression of SMN in neuronal cells and tissues, we raised a polyclonal antibody (abSMN) against a synthetic oligopeptide from SMN exon 2. AbSMN immunostaining in neuroblastoma cells and mouse and human central nervous system (CNS) showed intense labeling of nuclear "gems," along with prominent nucleolar immunoreactivity in mouse and human CNS tissues. Strong cytoplasmic labeling was observed in the perikarya and proximal dendrites of human spinal motor neurons but not in their axons. Immunoblot analysis revealed a 34-kDa species in the insoluble protein fractions from human SY5Y neuroblastoma cells, embryonic mouse spinal cord cultures, and human CNS tissue. By contrast, a 38-kDa species was detected in the cytosolic fraction of SY5Y cells. We conclude that SMN protein is expressed prominently in both the cytoplasm and nucleus in multiple types of neurons in brain and spinal cord, a finding consistent with a role for SMN as a determinant of neuronal viability.

Maintenance of acetylcholine receptor number by neuregulins at the neuromuscular junction in vivo.

ARIA (for acetylcholine receptor-inducing activity), a protein purified on the basis of its ability to stimulate acetylcholine receptor (AChR) synthesis in cultured myotubes, is a member of the neuregulin family and is present at motor endplates. This suggests an important role for neuregulins in mediating the nerve-dependent accumulation of AChRs in the postsynaptic membrane. Nerve-muscle synapses have now been analyzed in neuregulin-deficient animals. Mice that are heterozygous for the deletion of neuregulin isoforms containing an immunoglobulin-like domain are myasthenic. Postsynaptic AChR density is significantly reduced, as judged by the decrease in the mean amplitude of spontaneous miniature endplate potentials and bungarotoxin binding. On the other hand, the mean amplitude of evoked endplate potentials was not decreased, due to an increase in the number of quanta released per impulse, a compensation that has been observed in other myasthenic states. Thus, the density of AChRs in the postsynaptic membrane depends on immunoglobulin-containing neuregulin isoforms throughout the life of the animal.

ARIA is concentrated in the synaptic basal lamina of the developing chick neuromuscular junction.

ARIA is a member of a family of polypeptide growth and differentiation factors that also includes glial growth factor (GGF), neu differentiation factor, and heregulin. ARIA mRNA is expressed in all cholinergic neurons of the central nervous systems of rats and chicks, including spinal cord motor neurons. In vitro, ARIA elevates the rate of acetylcholine receptor incorporation into the plasma membrane of primary cultures of chick myotubes. To study whether ARIA may regulate the synthesis of junctional synaptic acetylcholine receptors in chick embryos, we have developed riboprobes and polyclonal antibody reagents that recognize isoforms of ARIA that include an amino-terminal immunoglobulin C2 domain and examined the expression and distribution of ARIA in motor neurons and at the neuromuscular junction. We detected significant ARIA mRNA expression in motor neurons as early as embryonic day 5, around the time that motor axons are making initial synaptic contacts with their target muscle cells. In older embryos and postnatal animals, we found ARIA protein concentrated in the synaptic cleft at neuromuscular junctions, consistent with transport down motor axons and release at nerve terminals. At high resolution using immunoelectron microscopy, we detected ARIA immunoreactivity exclusively in the synaptic basal lamina in a pattern consistent with binding to synapse specific components on the presynaptic side of the basal lamina. These results support a role for ARIA as a trophic factor released by motor neuron terminals that may regulate the formation of mature neuromuscular synapses.

ARIA is concentrated in nerve terminals at neuromuscular junctions and at other synapses.

Skeletal muscle ACh receptors (AChRs) accumulate at neuromuscular junctions (nmjs) at least partly because of the selective induction of AChR subunit genes in subsynaptic myotube nuclei by the motor nerve terminal. Additionally, mammalian AChRs undergo a postnatal change in subunit composition from embryonic (alpha 2 beta gamma delta) to adult (alpha 2 beta epsilon delta) forms, a switch that also depends on innervation. ARIA, a protein purified from chicken brains based on its ability to induce AChR synthesis in primary chick muscle cells, is a strong candidate for being the molecule responsible for these early developmental events. ARIA mRNA has been detected in embryonic motor neurons during synapse formation, and the gene continues to be expressed postnatally. In this report, we provide evidence that ARIA-like immunoreactivity is concentrated in rat motor nerve terminals from early postnatal ages, and that it can be detected in motor neurons in E18 embryos. ARIA is also detectable in axons within colchicine-treated sciatic nerves, suggesting that the protein in the nerve terminal has been transported from the cell body. ARIA mRNA is present in, but not restricted to, cholinergic neurons. Likewise, we report here that ARIA-like immunoreactivity is present in some noncholinergic central synapses. We also present evidence that isoforms of ARIA are differentially distributed among functionally distinct classes of neurons.

Merosin promotes neurite growth and Schwann cell migration in vitro and nerve regeneration in vivo: evidence using an antibody to merosin, ARM-1.

Monoclonal antibodies that block the cellular function(s) of specific antigens can provide valuable probes for in vitro and in vivo bioassays. With the goal of understanding the molecular basis of neuron-Schwann cell interactions during development and regeneration, we have sought antibodies that interfere with the function of merosin, the predominant laminin isoform present in the Schwann cell basement membrane. To identify the biological functions of merosin in the peripheral nervous system, we studied Schwann cell migration and neurite outgrowth in vitro and nerve regeneration in vivo, in the presence and the absence of a monoclonal antibody that we believe binds to merosin, ARM-1 (Anti Rodent Merosin-1). The ARM-1 antibody blocked both neurite outgrowth and Schwann cell migration in vitro. This antibody also reduced neuritic branching in vitro. In vivo, the ARM-1 antibody blocked the regeneration of sympathetic nerve fibers in the rat iris. The blockade of neurite outgrowth and Schwann cell migration by ARM-1 antibody suggests that merosin is involved in facilitating the two most critical cellular events during the normal development and regeneration of peripheral nerves, i.e., axon growth and Schwann cell migration. Furthermore, the regulation of both Schwann cell migration and axon growth by the ARM-1 antigen implies that these two cellular events obey a common set of molecular signals during the development and regeneration of peripheral nerves.

Primary T-cell lymphoma of the brainstem.

Most primary CNS lymphomas are non-Hodgkin's lymphomas of B-cell lineage. We report a case of a small lymphocytic-type T-cell lymphoma localized primarily to the brainstem and compare the characteristics of primary CNS T-cell lymphomas with those of primary CNS B-cell lymphomas.