Daclizumab phase II trial in relapsing and remitting multiple sclerosis: MRI and clinical results.

OBJECTIVE: Daclizumab is an interleukin 2 receptor alpha chain specific humanized monoclonal antibody that has shown promising therapeutic effects in multiple sclerosis (MS). Daclizumab treatment in patients with relapsing and remitting MS was administered to determine effects on MRI and clinical outcomes. METHODS: Patients with MS on interferon (IFN) therapy but with continuing relapses and contrast enhancing lesions (CEL) were selected. Patients were evaluated with monthly MRI scans and clinical rating scales starting 3 months prior to treatment and then at 0.5 to 27.5 months during treatment. Daclizumab (1 mg/kg IV) was administered twice in the first month (initiated and administered again in 2 weeks), followed by treatments every 4 weeks. IFN was continued until 5.5 months after daclizumab was initiated. Patients were then placed on daclizumab monotherapy. Patients with recurrent CEL were restarted on IFN with daclizumab therapy at (1.5 mg/kg IV) every 28 days. RESULTS: Nine patients qualified for inclusion and completed the trial. Efficacy measured by both total CEL and new CEL (p < 0.001), relapses, timed ambulation, Expanded Disability Status Scale, and Neurologic Rating Scale (p < 0.05 to p < 0.01) was observed. CONCLUSION: Daclizumab was effective in reducing contrast enhancing lesions and improving clinical scores in patients with relapsing and remitting multiple sclerosis with active disease not controlled by interferon therapy. These results provide evidence for long-term efficacy and support further clinical development of daclizumab.

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.

Controversies in neurological infectious diseases.

The past several years have seen major advances in our understanding of neurological infectious diseases, their diagnosis, and their treatment. Along with these advances, however, new information about infectious agents and new therapeutic options have also introduced both uncertainty and controversy in the approach and management of patients with diseases of the central nervous system. Here, we discuss six such areas: the long-term efficacy of HAART therapy in treatment of HIV infection; the role of viral infection in chronic fatigue syndrome; Rasmussen's encephalitis as an infectious or autoimmune disease; the spectrum of neurological diseases caused by rickettsial infection; the role of Mycoplasma pneumoniae in human central nervous system disease; and the possible association of Chlamydia pneumoniae and human herpesvirus 6 with multiple sclerosis.

Sustained clinical benefits of glatiramer acetate in relapsing multiple sclerosis patients observed for 6 years. Copolymer 1 Multiple Sclerosis Study Group.

In a randomized, placebo-controlled, double-blind study, glatiramer acetate (Copaxone) reduced the relapse rate and slowed accumulation of disability for patients with relapsing - remitting multiple sclerosis. Of the original 251 patients randomized to receive glatiramer acetate or placebo, 208 chose to continue in an open-label study with all patients receiving active drug. The majority of the original double-blind cohort continues to receive glatiramer acetate by daily subcutaneous injection and are evaluated at 6-month intervals and during suspected relapse. The data reported here are from approximately 6 years of organized evaluation, including the double-blind phase of up to 35 months and the open-label phase of over 36 months. Daily subcutaneous injections of 20 mg glatiramer acetate were well tolerated. The mean annual relapse rate of the patients who received glatiramer acetate since randomization and continued into the open-label study was 0.42 (95% confidence interval (CI), CI=0.34 - 0.51). The rate per year has continued to drop and for the sixth year is 0.23. Of the group who have received glatiramer acetate without interruption for 5 or more years, 69.3% were neurologically unchanged or have improved from baseline by at least one step on the Expanded Disability Status Scale (EDSS). Patients who left the open-label phase were surveyed by questionnaire. The majority responded, providing information about their current status and reasons for dropping out. This study demonstrates the sustained efficacy of glatiramer acetate in reducing the relapse rate and in slowing the accumulation of disability in patients with relapsing forms of multiple sclerosis. Multiple Sclerosis (2000) 6 255 - 266

Contrasting effects of anti-adhesion molecule therapy in experimental allergic encephalomyelitis and Theiler's murine encephalomyelitis.

An augmentation of experimental allergic encephalomyelitis (EAE) was observed when monoclonal antibody (mAb) to intercellular adhesion molecule 1 (ICAM-1) was administered after adoptive transfer. Clinical disease was more severe in the ICAM-1 specific mAb-treated EAE mice and included prominent ataxia compared to the PBS-treated controls or Theiler's murine encephalomyelitis virus (TMEV) infected mice treated with ICAM-1 specific mAb. Neuropathologic evaluation demonstrated a distinctly different distribution of lesions in the anti-ICAM-1-treated EAE mice which featured prominent demyelination and inflammation in the cerebellum, brainstem and cerebrum. These structures were minimally involved in the control mice and mAb treatment did not alter the neuropathology in TMEV-infected mice. These results indicate that anti-ICAM-1 can alter trafficking of lymphocytes and mononuclear cells in EAE but not TMEV-induced demyelinating disease.

Gender variations in early Theiler's virus induced demyelinating disease: differential susceptibility and effects of IL-4, IL-10 and combined IL-4 with IL-10.

Theiler's murine encephalomyelitis virus (TMEV) induced demyelinating disease, is an animal model of multiple sclerosis (MS). The viral-induced encephalitis is followed by an inflammatory and demyelinating disease. We quantitated the response of female and male mice during the transition from encephalitis to early demyelination. CNS neuropathology and antiviral antibody production were evaluated. Parallel studies were done with anti-inflammatory cytokines IL-4, IL-10 or a combination of IL-4 with IL-10. Results show female mice demonstrate an augmented susceptibility to the virus and a greater response to the cytokine therapies. Significant variation was noted during early demyelinating disease. The combination therapy of IL-4 with IL-10 produced striking decreases in antiviral antibody levels and virus-induced neuropathologic disease. Male mice are less susceptible to viral-induced disease and are less responsive to the cytokine treatments. Gender bias in TMEV-induced demyelinating disease appears to parallel the differences noted with other experimental immune diseases.

Extended use of glatiramer acetate (Copaxone) is well tolerated and maintains its clinical effect on multiple sclerosis relapse rate and degree of disability. Copolymer 1 Multiple Sclerosis Study Group.

When 251 relapsing-remitting patients with multiple sclerosis were randomized to receive daily subcutaneous injections of glatiramer acetate, previously called copolymer 1 (Copaxone; n = 125) or placebo (n = 126) for 24 months, there were no laboratory abnormalities associated with glatiramer acetate treatment and it was well tolerated with few side effects. Patients receiving glatiramer acetate had significantly fewer relapses and were more likely to be neurologically improved, whereas those receiving placebo were more likely to worsen. This study was extended for 1 to 11 months (mean of 5.2 months for the glatiramer acetate group and 5.9 months for the placebo group). The blinding and study conditions used during the core 24-month study were unchanged throughout the extension. The results of this extension study confirm the excellent tolerance and safety profile of glatiramer acetate for injection. The clinical benefit of glatiramer acetate for both the relapse rate and for neurologic disability was sustained at the end of the extension trial.

Nitric oxide synthase inhibitor, aminoguanidine, reduces inflammation and demyelination produced by Theiler's virus infection.

This study evaluated effects of the inducible nitric oxide synthase (iNOS) inhibitor, aminoguanidine (AG), on the neuropathology and clinical disease produced by Theiler's murine encephalomyelitis virus (TMEV) DA strain infection. Treatment with AG was started on day 7, 14, 28 or 66 post-inoculation and continued for a minimum of 21 days. Inflammation, demyelination and axonal necrosis were scored in a blinded fashion on spinal cord sections from each mouse. Reduction in inflammation, demyelination and axonal necrosis was observed in mice treated with AG. Apoptosis within the spinal cord parenchyma and perivascular cuffs was significantly decreased. AG treatment resulted in delayed onset of clinical disease.

Use of conformationally restricted benzamidines as arginine surrogates in the design of platelet GPIIb-IIIa receptor antagonists.

The use of 5,6-bicyclic amidines as arginine surrogates in the design of a novel class of potent platelet glycoprotein IIb-IIIa receptor (GPIIb-IIIa) antagonists is described. The additional conformational restriction offered by the bicyclic nucleus results in 20-400-fold increases in potency compared to the freely flexible, acyclic benzamidine counterpart. The design, synthesis, structure-activity relationships (SAR), and in vitro activity of this novel class of GPIIb-IIIa antagonists are presented.

Open label gabapentin treatment for pain in multiple sclerosis.

Pain is a frequent and distressing complaint in patients with multiple sclerosis (MS) and may present a difficult therapeutic problem. Conventional therapy is moderately effective and includes, among others, a variety of anticonvulsant medications. Gabapentin (Neurontin) is a new generation antiepileptic drug which appears to be advantageous in treatment of intractable pain of reflex sympathetic dystrophy. This study investigates the benefits of open-label treatment with gabapentin for pain control in 25 patients with MS. Excellent to moderate pain relief was obtained in a substantial number of patients. Throbbing pains and needles, and cramping pains responded best, and dull aching pains responded least to the medication. There was no significant change in distribution and type of pain as a result of this treatment. Mild to moderate side effects were observed. Cautious escalation of the dose of gabapentin is advisable in MS patients. Further clinical trials with larger patient groups are recommended.

Multiple sclerosis presenting as transverse myelopathy: clinical and MRI features.

We described specific MRI features of MS presenting with acute partial transverse myelopathy. We reviewed the clinical histories and MRI studies of brain and spinal cord of 24 patients, using axial and sagittal images of the spinal cord to define patterns of signal abnormality in the context of clinical presentation, course, and vertebral column structural pathology. The heterogeneity of spinal cord tract involvement was greater than previously reported, with signal abnormality identified within the central cord, crossing the gray-white junction, and involving all four major funiculi. Correlation between spinal cord MRI findings and neurologic deficits was strong (100% by axial images; 96% by sagittal images). Serial spinal cord MRI demonstrated the dynamic nature of the signal abnormalities over time and in response to high-dose steroid treatment. No cranial MRI abnormality initially was seen in 36% of cases with evidence of demyelinating disease on concurrent spinal MRI.

Fibrinogen receptor (GPIIb-IIIa) antagonists derived from 5,6-bicyclic templates. Amidinoindoles, amidinoindazoles, and amidinobenzofurans containing the N-alpha-sulfonamide carboxylic acid function as potent platelet aggregation inhibitors.

A series of highly potent and specific fibrinogen receptor antagonists have been discovered and optimized through structural modification of the novel amidinoindole and benzofuran compounds, I and II. Systematic linker optimization afforded the amidinobenzofuran-containing inhibitor 29, which displayed an IC50 value of 250 nM in platelet aggregation assays. Attempts to enhance activity by modification of the beta-position of the beta-alanyl carboxylate group of 29 had only a modest effect on inhibitory activity in aggregation assays. Analogues prepared to enhance the activity by conformational restriction were also found to be equally or less potent. In contrast, modification at the alpha-position of the beta-alanyl carboxylate group resulted in the identification of extremely potent and novel amidinobenzofuran-containing derivatives 46-49. Reexamination of 5,6-bicyclic aromatic nucleus led to the further identification of amidinoindole- and amidinoindazole-containing derivatives 53-55. These analogues, 46-49 and 53-55, exhibited potent in vitro activity with IC50 values of 25-65 nM in platelet aggregation assays and an IC50 value of 2 nM in fibrinogen binding assays and demonstrated a selectivity of > 50,000-fold for GPIIb-IIIa versus the most closely related integrin, the vitronectin receptor, alpha v beta 3.

Binding of a novel 50-kilodalton alboaggregin from Trimeresurus albolabris and related viper venom proteins to the platelet membrane glycoprotein Ib-IX-V complex. Effect on platelet aggregation and glycoprotein Ib-mediated platelet activation.

Binding of the multimeric adhesive glycoprotein, von Willebrand Factor (vWF), to the platelet membrane glycoprotein (GP) Ib-IX-V complex mediates platelet adhesion and initiates signal transduction leading to platelet activation. Recently described viper venom proteins that bind to the GP Ib alpha-chain and inhibit vWF binding provide novel probes for studying receptor function. We have purified a 50-kDa form of alboaggregin from the white-lipped tree viper (Trimeresurus albolabris) and two 25-kDa proteins, CHH-A and CHH-B, from the timber rattlesnake (Crotalus horridus horridus) in addition to a previously described 25-kDa alboaggregin and echicetin. Complete or partial amino acid sequencing of CHH-A, CHH-B, and 50-kDa alboaggregin and cross-reactivity of these proteins with an anti-botrocetin antiserum confirmed that they were disulfide-linked heterodimers or higher multimers of the C-type lectin protein family. These proteins, together with 25-kDa alboaggregin and echicetin, specifically bound to GP Ib alpha within the N-terminal peptide domain, His-1-Glu-282, and inhibited vWF binding with comparable IC50 values (approximately 0.2 microgram/mL). However, cross-blocking studies between these structurally related proteins and anti-GP Ib alpha monoclonal antibodies demonstrated that the venom protein binding sites were not congruent. Further, the 50-kDa alboaggregin, but not the other venom proteins, potently induced platelet activation as assessed by dense granule serotonin release or elevation of cytosolic ionized calcium. Treatment of platelets with the 50-kDa alboaggregin was associated with activation of protein kinase C and tyrosine kinase(s), resulting in a platelet protein phosphorylation profile similar to that seen on shear-stress-induced vWF binding to platelets. These results suggest that the 50-kDa alboaggregin induces cytoplasmic signaling coincident with its binding to the GP Ib-IX-V complex and provides a potentially useful probe for studying the mechanism of vWF-dependent platelet activation.

Multiple sclerosis.

Multiple sclerosis is a chronic disease that begins in late adolescence or adulthood. It is highly variable in its expression and severity. It is believed to be autoimmune in nature. The cause is unknown; both genetic and environmental factors have been implicated in the pathogenesis. MS generally presents with the acute or subacute onset of neurologic abnormalities that may wax and wane over many years. Diagnosis is generally made by means of observation of the clinical course in conjunction with a neurologic examination and laboratory tests. These tests may include magnetic resonance imaging of the head and spine, lumbar puncture, and evoked potentials. Treatment is based on general supportive care, the use of corticosteroids for relapses, and symptomatic management of ongoing problems. The frequency of relapses can be reduced with interferon-beta (Betaseron). Copolymer 1 and interferon-beta la are being evaluated by the U.S. Food and Drug Administration for approval for use for reduction in the frequency of relapses in relapsing-remitting MS. Treatment of chronic progression is often attempted with immunosuppressive agents such as corticosteroids, azathioprine, and cyclophosphamide. Use of other agents is being investigated.

Copolymer 1 reduces relapse rate and improves disability in relapsing-remitting multiple sclerosis: results of a phase III multicenter, double-blind placebo-controlled trial. The Copolymer 1 Multiple Sclerosis Study Group.

We studied copolymer 1 (Copaxone) in a multicenter (11-university) phase III trial of patients with relapsing-remitting multiple sclerosis (MS). Two hundred fifty-one patients were randomized to receive copolymer 1 (n = 125) or placebo (n = 126) at a dosage of 20 mg by daily subcutaneous injection for 2 years. The primary end point was a difference in the MS relapse rate. The final 2-year relapse rate was 1.19 +/- 0.13 for patients receiving copolymer 1 and 1.68 +/- 0.13 for those receiving placebo, a 29% reduction in favor of copolymer 1 (p = 0.007) (annualized rates = 0.59 for copolymer 1 and 0.84 for placebo). Trends in the proportion of relapse-free patients and median time to first relapse favored copolymer 1. Disability was measured by the Expanded Disability Status Scale (EDSS), using a two-neurologist (examining and treating) protocol. When the proportion of patients who improved, were unchanged, or worsened by > or = 1 EDSS step from baseline to conclusion (2 years) was evaluated, significantly more patients receiving copolymer 1 were found to have improved and more receiving placebo worsened (p = 0.037). Patient withdrawals were 19 (15.2%) from the copolymer 1 group and 17 (13.5%) from the placebo group at approximately the same intervals. The treatment was well tolerated. The most common adverse experience was an injection-site reaction. Rarely, a transient self-limited systemic reaction followed the injection in 15.2% of those receiving copolymer 1 and 3.2% of those receiving placebo.(ABSTRACT TRUNCATED AT 250 WORDS)

Uptake of systemically administered human anticerebellar antibody by rat Purkinje cells following blood-brain barrier disruption.

Paraneoplastic cerebellar degeneration accompanying gynecological or breast malignancies is frequently associated with an autoantibody response, termed "type I" or "anti-Yo" directed against cytoplasmic antigens of cerebellar Purkinje cells. The role of this antibody response in the pathogenesis of paraneoplastic cerebellar degeneration is unknown; however, it is also not known whether anti-Purkinje cell antibodies from the systemic circulation bind to target Purkinje cell antigens under the conditions of brain inflammation and blood-brain barrier disruption, which are frequently present at the onset of cerebellar symptoms. Inbred Lewis rats received intraperitoneal injections of type I or normal IgG in the setting of blood-brain barrier disruption induced by adoptive transfer of experimental allergic encephalomyelitis (EAE) and were killed after 24, 48, and 96 h. Brains of these animals were studied histologically for evidence of EAE and immunohistochemically for binding of human or endogenous rat IgG to target neurons. Rat IgG was detected around vessels and in Purkinje cells of all animals studied. Human IgG was detected around vessels of all animals. In animals examined 96h after receiving type I human IgG, human IgG was identified within processes of Purkinje cells and within occasional Purkinje cell bodies. Uptake of type I IgG by other cell types was not observed, and neuronal uptake of IgG was not seen in brains of animals receiving normal human IgG. Our data demonstrate that circulating type I IgG is internalized by cerebellar Purkinje cells in the setting of blood-brain barrier disruption and suggest a mechanism by which an antibody response directed against cytoplasmic antigens of Purkinje cells may reach target antigens at the onset of paraneoplastic cerebellar degeneration.