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Dive into the research topics where Douglas L. Arnold is active.

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Featured researches published by Douglas L. Arnold.


The Lancet | 2012

Alemtuzumab for patients with relapsing multiple sclerosis after disease-modifying therapy: a randomised controlled phase 3 trial.

Alasdair Coles; Cary Twyman; Douglas L. Arnold; Jeffrey Cohen; Christian Confavreux; Edward Fox; Hans-Peter Hartung; Eva Havrdova; Krzysztof Selmaj; Howard L. Weiner; Tamara Miller; Elizabeth Fisher; Rupert Sandbrink; Stephen Lake; David Margolin; Pedro Oyuela; Michael Panzara; D Alastair S Compston

BACKGROUND The anti-CD52 monoclonal antibody alemtuzumab reduces disease activity in previously untreated patients with relapsing-remitting multiple sclerosis. We aimed to assess efficacy and safety of alemtuzumab compared with interferon beta 1a in patients who have relapsed despite first-line treatment. METHODS In our 2 year, rater-masked, randomised controlled phase 3 trial, we enrolled adults aged 18-55 years with relapsing-remitting multiple sclerosis and at least one relapse on interferon beta or glatiramer. Eligible participants were randomly allocated in a 1:2:2 ratio by an interactive voice response system, stratified by site, to receive subcutaneous interferon beta 1a 44 μg, intravenous alemtuzumab 12 mg per day, or intravenous alemtuzumab 24 mg per day. Interferon beta 1a was given three-times per week and alemtuzumab was given once per day for 5 days at baseline and for 3 days at 12 months. The 24 mg per day group was discontinued to aid recruitment, but data are included for safety assessments. Coprimary endpoints were relapse rate and time to 6 month sustained accumulation of disability, comparing alemtuzumab 12 mg and interferon beta 1a in all patients who received at least one dose of study drug. This study is registered with ClinicalTrials.gov, number NCT00548405. FINDINGS 202 (87%) of 231 patients randomly allocated interferon beta 1a and 426 (98%) of 436 patients randomly allocated alemtuzumab 12 mg were included in the primary analyses. 104 (51%) patients in the interferon beta 1a group relapsed (201 events) compared with 147 (35%) patients in the alemtuzumab group (236 events; rate ratio 0·51 [95% CI 0·39-0·65]; p<0·0001), corresponding to a 49·4% improvement with alemtuzumab. 94 (47%) patients in the interferon beta 1a group were relapse-free at 2 years compared with 278 (65%) patients in the alemtuzumab group (p<0·0001). 40 (20%) patients in the interferon beta 1a group had sustained accumulation of disability compared with 54 (13%) in the alemtuzumab group (hazard ratio 0·58 [95% CI 0·38-0·87]; p=0·008), corresponding to a 42% improvement in the alemtuzumab group. For 435 patients allocated alemtuzumab 12 mg, 393 (90%) had infusion-associated reactions, 334 (77%) had infections (compared with 134 [66%] of 202 patients in the interferon beta 1a group) that were mostly mild-moderate with none fatal, 69 (16%) had thyroid disorders, and three (1%) had immune thrombocytopenia. INTERPRETATION For patients with first-line treatment-refractory relapsing-remitting multiple sclerosis, alemtuzumab could be used to reduce relapse rates and sustained accumulation of disability. Suitable risk management strategies allow for early identification of alemtuzumabs main adverse effect of secondary autoimmunity. FUNDING Genzyme (Sanofi) and Bayer Schering Pharma.


The Lancet | 2012

Alemtuzumab versus interferon beta 1a as first-line treatment for patients with relapsing-remitting multiple sclerosis: a randomised controlled phase 3 trial

Jeffrey Cohen; Alasdair Coles; Douglas L. Arnold; Christian Confavreux; Edward Fox; Hans-Peter Hartung; Eva Havrdova; Krzysztof Selmaj; Howard L. Weiner; Elizabeth Fisher; Vesna V. Brinar; Gavin Giovannoni; Miroslav Stojanovic; Bella Ertik; Stephen Lake; David Margolin; Michael Panzara; D Alastair S Compston

BACKGROUND The anti-CD52 monoclonal antibody alemtuzumab reduced disease activity in a phase 2 trial of previously untreated patients with relapsing-remitting multiple sclerosis. We aimed to assess efficacy and safety of first-line alemtuzumab compared with interferon beta 1a in a phase 3 trial. METHODS In our 2 year, rater-masked, randomised controlled phase 3 trial, we enrolled adults aged 18-50 years with previously untreated relapsing-remitting multiple sclerosis. Eligible participants were randomly allocated in a 2:1 ratio by an interactive voice response system, stratified by site, to receive intravenous alemtuzumab 12 mg per day or subcutaneous interferon beta 1a 44 μg. Interferon beta 1a was given three-times per week and alemtuzumab was given once per day for 5 days at baseline and once per day for 3 days at 12 months. Coprimary endpoints were relapse rate and time to 6 month sustained accumulation of disability in all patients who received at least one dose of study drug. This study is registered with ClinicalTrials.gov, number NCT00530348. FINDINGS 187 (96%) of 195 patients randomly allocated interferon beta 1a and 376 (97%) of 386 patients randomly allocated alemtuzumab were included in the primary analyses. 75 (40%) patients in the interferon beta 1a group relapsed (122 events) compared with 82 (22%) patients in the alemtuzumab group (119 events; rate ratio 0·45 [95% CI 0·32-0·63]; p<0.0001), corresponding to a 54·9% improvement with alemtuzumab. Based on Kaplan-Meier estimates, 59% of patients in the interferon beta 1a group were relapse-free at 2 years compared with 78% of patients in the alemtuzumab group (p<0·0001). 20 (11%) of patients in the interferon beta 1a group had sustained accumulation of disability compared with 30 (8%) in the alemtuzumab group (hazard ratio 0·70 [95% CI 0·40-1·23]; p=0·22). 338 (90%) of patients in the alemtuzumab group had infusion-associated reactions; 12 (3%) of which were regarded as serious. Infections, predominantly of mild or moderate severity, occurred in 253 (67%) patients treated with alemtuzumab versus 85 (45%) patients treated with interferon beta 1a. 62 (16%) patients treated with alemtuzumab had herpes infections (predominantly cutaneous) compared with three (2%) patients treated with interferon beta 1a. By 24 months, 68 (18%) patients in the alemtuzumab group had thyroid-associated adverse events compared with 12 (6%) in the interferon beta 1a group, and three (1%) had immune thrombocytopenia compared with none in the interferon beta 1a group. Two patients in the alemtuzumab group developed thyroid papillary carcinoma. INTERPRETATION Alemtuzumabs consistent safety profile and benefit in terms of reductions of relapse support its use for patients with previously untreated relapsing-remitting multiple sclerosis; however, benefit in terms of disability endpoints noted in previous trials was not observed here. FUNDING Genzyme (Sanofi) and Bayer Schering Pharma.


Annals of Neurology | 2008

Rituximab in Relapsing-Remitting Multiple Sclerosis : A 72-Week, Open-Label, Phase I Trial

Amit Bar-Or; Peter A. Calabresi; Douglas L. Arnold; Clyde Markowitz; Stuart Shafer; Lloyd H. Kasper; Emmanuelle Waubant; Suzanne Gazda; Robert J. Fox; Michael Panzara; Neena Sarkar; Sunil Agarwal; Craig H. Smith

We evaluated the safety, tolerability, pharmacodynamics, and activity of B‐cell depletion with rituximab in patients with relapsing‐remitting multiple sclerosis, receiving two courses of rituximab 6 months apart, and followed for a total of 72 weeks. No serious adverse events were noted; events were limited to mild‐to‐moderate infusion‐associated events, which tended to decrease with subsequent infusions. Infections were also mild or moderate, and none led to withdrawal. Fewer new gadolinium‐enhancing or T2 lesions were seen starting from week 4 and through week 72. An apparent reduction in relapses was also observed over the 72 weeks compared with the year before therapy. Ann Neurol 2008


Annals of Neurology | 1999

Neuroimaging evidence of progressive neuronal loss and dysfunction in temporal lobe epilepsy

Edwin Tasch; Fernando Cendes; Li Min Li; François Dubeau; Frederick Andermann; Douglas L. Arnold

Whether temporal lobe epilepsy is the result of an isolated, early injury or whether there is ongoing neuronal dysfunction or loss due to seizures is often debated. We attempt to address this issue by using magnetic resonance techniques. Proton magnetic resonance spectroscopic imaging can detect and quantify focal neuronal dysfunction or loss based on reduced signals from the neuronal marker N‐acetylaspartate (NAA), and magnetic resonance imaging (MRI)‐based measurements of hippocampal volumes (MRIvol) can quantify the amount of atrophy in this structure. We performed magnetic resonance spectroscopic imaging and MRIvol in 82 consecutive patients with medically intractable temporal lobe epilepsy to determine whether there was a correlation between seizure frequency, or type or duration of epilepsy, with NAA to creatine (Cr) values or hippocampal volumes. Volumes and spectroscopic resonance intensities were categorized as to whether they were measured from the temporal lobe ipsilateral or contralateral to the predominant electroencephalographic focus. Ipsilateral and contralateral NAA/Cr was negatively correlated with duration of epilepsy. Hippocampal volumes were negatively correlated with duration ipsilaterally but not contralaterally. Frequency of complex partial seizures was not correlated with any of the magnetic resonance measures. However, patients with frequent generalized tonic–clonic seizures had lower NAA/Cr bilaterally and smaller hippocampal volumes ipsilaterally than patients with none or rare generalized tonic–clonic seizures. The results suggest that although an early, fixed injury may cause asymmetric temporal lobe damage, generalized seizures may also cause progressive neuronal dysfunction or loss. Ann Neurol 1999;45:568–576


Lancet Neurology | 2011

Clinical, environmental, and genetic determinants of multiple sclerosis in children with acute demyelination: a prospective national cohort study

Brenda Banwell; Amit Bar-Or; Douglas L. Arnold; Dessa Sadovnick; Sridar Narayanan; Melissa McGowan; Julia O'Mahony; Sandra Magalhaes; Heather Hanwell; Reinhold Vieth; Raymond Tellier; Thierry Vincent; Giulio Disanto; George C. Ebers; Katherine Wambera; Mary B. Connolly; Jerome Y. Yager; Jean K. Mah; Fran Booth; Guillaume Sébire; David J.A. Callen; Brandon Meaney; Marie-Emmanuelle Dilenge; Anne Lortie; Daniela Pohl; Asif Doja; Sunita Venketaswaran; Simon Levin; E. Athen MacDonald; David Meek

BACKGROUND HLA-DRB1*15 genotype, previous infection with Epstein-Barr virus, and vitamin D insufficiency are susceptibility factors for multiple sclerosis, but whether they act synergistically to increase risk is unknown. We aimed to assess the contributions of these risk factors and the effect of established precursors of multiple sclerosis, such as brain lesions on MRI and oligoclonal bands in CSF at the time of incident demyelination, on development of multiple sclerosis in children. METHODS In our prospective national cohort study, we assessed children who presented with incident CNS demyelination to any of the 16 paediatric health-care facilities or seven regional health-care facilities in Canada. We did univariate and multivariable analyses to assess contributions of HLA-DRB1*15, Epstein-Barr virus, vitamin D status, MRI evidence of brain lesions, and CSF oligoclonal bands as determinants of multiple sclerosis. We used classification and regression tree analyses to generate a risk stratification algorithm for clinical use. FINDINGS Between Sept 1, 2004, and June 30, 2010, we screened 332 children of whom 302 (91%) were eligible and followed-up for a median of 3·14 years (IQR 1·61-4·51). 63 (21%) children were diagnosed with multiple sclerosis after a median of 127 days (99-222). Although the risk of multiple sclerosis was increased with presence of one or more HLA-DRB1*15 alleles (hazard ratio [HR] 2·32, 95% CI 1·25-4·30), reduced serum 25-hydroxyvitamin D concentration (HR per 10 nmol/L decrease 1·11, 1·00-1·25), and previous Epstein-Barr-virus infection (HR 2·04, 0·99-4·20), no interactions between these variables were detected on multivariate analysis. Multiple sclerosis was strongly associated with baseline MRI evidence of one or more brain lesion (HR 37·9, 5·26-273·85) or CSF oligoclonal bands (6·33, 3·35-11·96), suggesting established disease. One patient diagnosed with multiple sclerosis had a normal MRI scan, and therefore sensitivity of an abnormal MRI scan for multiple sclerosis diagnosis was 98·4%. INTERPRETATION Risk of multiple sclerosis in children can be stratified by presence of HLA-DRB1*15 alleles, remote Epstein-Barr virus infection, and low serum 25-hydroxyvitamin D concentrations. Similar to previous studies in adults, brain lesions detected on MRI and CSF oligoclonal bands in children are probable precursors to the clinical onset of multiple sclerosis. Children with a normal MRI are very likely to have a monophasic illness. FUNDING Canadian Multiple Sclerosis Scientific Research Foundation.


Lancet Neurology | 2014

Pegylated interferon beta-1a for relapsing-remitting multiple sclerosis (ADVANCE): a randomised, phase 3, double-blind study

Peter A. Calabresi; Bernd C. Kieseier; Douglas L. Arnold; Laura J. Balcer; Alexey Boyko; Jean Pelletier; Shifang Liu; Ying Zhu; Ali Seddighzadeh; Serena Hung; Aaron Deykin

BACKGROUND Subcutaneous pegylated interferon (peginterferon) beta-1a is being developed for treatment of relapsing multiple sclerosis, with less frequent dosing than currently available first-line injectable treatments. We assessed the safety and efficacy of peginterferon beta-1a after 48 weeks of treatment in the placebo-controlled phase of the ADVANCE trial, a study of patients with relapsing-remitting multiple sclerosis. METHODS We did this 2-year, double-blind, parallel group, phase 3 study, with a placebo-controlled design for the first 48 weeks, at 183 sites in 26 countries. Patients with relapsing-remitting multiple sclerosis (age 18-65 years, with Expanded Disability Status Scale score ≤5) were randomly assigned (1:1:1) via an interactive voice response or web system, and stratified by site, to placebo or subcutaneous peginterferon beta-1a 125 μg once every 2 weeks or every 4 weeks. The primary endpoint was annualised relapse rate at 48 weeks. This trial is registered with ClinicalTrials.gov, number NCT00906399. FINDINGS We screened 1936 patients and enrolled 1516, of whom 1512 were randomly assigned (500 to placebo, 512 to peginterferon every 2 weeks, 500 to peginterferon every 4 weeks); 1332 (88%) patients completed 48 weeks of treatment. Adjusted annualised relapse rates were 0·397 (95% CI 0·328-0·481) in the placebo group versus 0·256 (0·206-0·318) in the every 2 weeks group and 0·288 (0·234-0·355) in the every 4 weeks group (rate ratio for every 2 weeks group 0·644, 95% CI 0·500-0·831, p=0·0007; rate ratio for the every 4 weeks group 0·725, 95% CI 0·565-0·930, p=0·0114). 417 (83%) patients taking placebo, 481 (94%) patients taking peginterferon every 2 weeks, and 472 (94%) patients taking peginterferon every 4 weeks reported adverse events including relapses. The most common adverse events associated with peginterferon beta-1a were injection site reactions, influenza-like symptoms, pyrexia, and headache. 76 (15%) patients taking placebo, 55 (11%) patients taking study drug every 2 weeks, and 71 (14%) patients taking study drug every 4 weeks reported serious adverse events; relapse, pneumonia, and urinary tract infection were the most common. INTERPRETATION After 48 weeks, peginterferon beta-1a significantly reduced relapse rate compared with placebo. The drug might be an effective treatment for relapsing-remitting multiple sclerosis with less frequent administration than available treatments. FUNDING Biogen Idec.


Neuroreport | 1998

Recovery of N-acetylaspartate in corticomotor neurons of patients with ALS after riluzole therapy

Sanjay Kalra; Neil R. Cashman; Angela Genge; Douglas L. Arnold

RILUZOLE, a glutamate antagonist, has been shown to be efficacious in the treatment of patients with amyotrophic lateral sclerosis (ALS), allowing prolonged survival and time to tracheostomy. The efficacy of riluzole in thought to result from reduced glutamate excitotoxicity on motor neurons of patients with ALS, but this has never been demonstrated directly in vivo. N-acetylaspartate (NAA), a compound that is readily measured in vivo using proton magnetic resonance spectroscopy, can be used as a surrogate marker for neuronal loss or sublethal injury. To determine whether riluzole reverses sublethal corticomotoneuron damage in patients with ALS we measured NAA/creatine (Cr) relative intensity ratios in the motor cortex before and after treatment with riluzole 50 mg bid. After 3 weeks of riluzole therapy in 11 patients NAA/Cr increased from 2.14 ± 0.26 to 2.27 ± 0.24 (p = 0.044), whereas, in 12 untreated patients NAA/Cr decreased from 2.17 ± 0.20 to 2.08 ± 0.20 (p = 0.099). Thus the change in NAA/Cr between the treated and untreated groups was 0.22 ± 0.095 (p = 0.008). The magnitude of increase in NAA/Cr in those treated was not correlated with age, sex, duration of treatment or disease, the presence of probable or definite upper motor neuron (UMN) signs, bulbar features, or pre-treatment NAA/Cr. We conclude that magnetic resonance spectroscopy can provide a novel surrogate measure of neuronal integrity that demonstrates reversal of sublethal UMN injury in patients with ALS within weeks of initiating riluzole therapy.


Journal of Neurology | 2001

Axonal metabolic recovery in multiple sclerosis patients treated with interferon β-1b

Sridar Narayanan; Nicola De Stefano; Gordon S. Francis; Rozie Arnaoutelis; Zografos Caramanos; D. Louis Collins; Daniel Pelletier; Barry G. W. Arnason; Jack P. Antel; Douglas L. Arnold

Abstract Patients with multiple sclerosis (MS) can benefit from treatment with interferon β–1b. However, the mechanisms of action of this drug are incompletely understood and effects of interferon β–1b on axonal injury are not known. A measure of axonal injury can be obtained in vivo using magnetic resonance spectroscopy to quantify the resonance intensity of the neuronal marker, N-acetylaspartate (NAA). In a small pilot study, we performed combined magnetic resonance imaging and magnetic resonance spectroscopic imaging on 10 patients with relapsing-remitting MS before and 1 year after starting treatment with subcutaneous interferon β–1b. Resonance intensities of NAA relative to creatine (Cr) were measured in a large, central brain volume. These measurements were compared with those made in a group of 6 untreated patients selected to have a similar range of scores on the Expanded Disability Status Scale and mean NAA/Cr at baseline. NAA/Cr in the treated group [2.74 (0.16), mean (SD)] showed an increase of 5.5 % 12 months after the start of therapy [2.89 (0.24), p = 0.05], while NAA/Cr in the untreated group decreased, but not significantly [2.76 (0.1) at baseline, 2.65 (0.14) at 12 months, p > 0.1]. NAA/Cr had become significantly higher in the treated group at 12 months than in the untreated group (p = 0.03). Our data suggest that, in addition to losing axons, patients with chronic multiple sclerosis suffer from chronic, sublethal axonal injury that is at least partially reversible with interferon β–1b therapy.


Medical Image Analysis | 2013

Review of automatic segmentation methods of multiple sclerosis white matter lesions on conventional magnetic resonance imaging

Daniel García-Lorenzo; Simon J. Francis; Sridar Narayanan; Douglas L. Arnold; D. Louis Collins

Magnetic resonance (MR) imaging is often used to characterize and quantify multiple sclerosis (MS) lesions in the brain and spinal cord. The number and volume of lesions have been used to evaluate MS disease burden, to track the progression of the disease and to evaluate the effect of new pharmaceuticals in clinical trials. Accurate identification of MS lesions in MR images is extremely difficult due to variability in lesion location, size and shape in addition to anatomical variability between subjects. Since manual segmentation requires expert knowledge, is time consuming and is subject to intra- and inter-expert variability, many methods have been proposed to automatically segment lesions. The objective of this study was to carry out a systematic review of the literature to evaluate the state of the art in automated multiple sclerosis lesion segmentation. From 1240 hits found initially with PubMed and Google scholar, our selection criteria identified 80 papers that described an automatic lesion segmentation procedure applied to MS. Only 47 of these included quantitative validation with at least one realistic image. In this paper, we describe the complexity of lesion segmentation, classify the automatic MS lesion segmentation methods found, and review the validation methods applied in each of the papers reviewed. Although many segmentation solutions have been proposed, including some with promising results using MRI data obtained on small groups of patients, no single method is widely employed due to performance issues related to the high variability of MS lesion appearance and differences in image acquisition. The challenge remains to provide segmentation techniques that work in all cases regardless of the type of MS, duration of the disease, or MRI protocol, and this within a comprehensive, standardized validation framework. MS lesion segmentation remains an open problem.


Neurology | 2011

A phase 2 randomized trial of ELND005, scyllo-inositol, in mild to moderate Alzheimer disease

Stephen Salloway; Reisa A. Sperling; Ron Keren; Anton P. Porsteinsson; C.H. van Dyck; Pierre N. Tariot; Sid Gilman; Douglas L. Arnold; Susan Abushakra; C. Hernandez; Gerald Crans; Earvin Liang; G. Quinn; Menghis Bairu; Aleksandra Pastrak; Jesse M. Cedarbaum

Objective: This randomized, double-blind, placebo-controlled, dose-ranging phase 2 study explored safety, efficacy, and biomarker effects of ELND005 (an oral amyloid anti-aggregation agent) in mild to moderate Alzheimer disease (AD). Methods: A total of 353 patients were randomized to ELND005 (250, 1,000, or 2,000 mg) or placebo twice daily for 78 weeks. Coprimary endpoints were the Neuropsychological Test Battery (NTB) and Alzheimers Disease Cooperative Study–Activities of Daily Living (ADCS-ADL) scale. The primary analysis compared 250 mg (n =84) to placebo (n =82) after an imbalance of infections and deaths led to early discontinuation of the 2 higher dose groups. Results: The 250 mg dose demonstrated acceptable safety. The primary efficacy analysis at 78 weeks revealed no significant differences between the treatment groups on the NTB or ADCS-ADL. Brain ventricular volume showed a small but significant increase in the overall 250 mg group (p =0.049). At the 250 mg dose, scyllo-inositol concentrations increased in CSF and brain and CSF Aβx-42 was decreased significantly compared to placebo (p =0.009). Conclusions: Primary clinical efficacy outcomes were not significant. The safety and CSF biomarker results will guide selection of the optimal dose for future studies, which will target earlier stages of AD. Classification of evidence: Due to the small sample sizes, this Class II trial provides insufficient evidence to support or refute a benefit of ELND005.

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Sridar Narayanan

Montreal Neurological Institute and Hospital

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Amit Bar-Or

Montreal Neurological Institute and Hospital

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Krzysztof Selmaj

Medical University of Łódź

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Eva Havrdova

Charles University in Prague

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D. Louis Collins

Montreal Neurological Institute and Hospital

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Brenda Banwell

Children's Hospital of Philadelphia

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