Paul O’Connor
St. Michael's Hospital
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Featured researches published by Paul O’Connor.
Journal of Neurology | 2009
Michael Hutchinson; Ludwig Kappos; Peter A. Calabresi; Christian Confavreux; Gavin Giovannoni; Steven L. Galetta; Eva Havrdova; Fred D. Lublin; David H. Miller; Paul O’Connor; J. Theodore Phillips; Chris H. Polman; Ernst-Wilhelm Radue; Richard A. Rudick; William H. Stuart; A Wajgt; Bianca Weinstock-Guttman; Daniel Wynn; Frances Lynn; Michael Panzara; Sentinel Investigators
The AFFIRM and SENTINEL studies showed that natalizumab was effective both as monotherapy and in combination with interferon beta (IFNβ)-1a in patients with relapsing multiple sclerosis (MS). Further analyses of AFFIRM and SENTINEL data were conducted to determine the efficacy of natalizumab in prespecified patient subgroups according to baseline characteristics: relapse history 1 year before randomization (1, 2, ≥ 3), Expanded Disability Status Scale score (≤ 3.5, > 3.5), number of T2 lesions (< 9, ≥ 9), presence of gadolinium-enhancing (Gd+) lesions (0, ≥ 1), age (< 40, ≥ 40) and gender (male, female). A post hoc analysis was conducted to determine the efficacy of natalizumab in patients with highly active disease (i. e., ≥ 2 relapses in the year before study entry and ≥ 1 Gd+ lesion at study entry). In both AFFIRM and SENTINEL studies natalizumab reduced the annualized relapse rates across all subgroups (except the small subgroups with < 9 baseline T2 lesions) over 2 years. In AFFIRM, natalizumab significantly reduced the risk of sustained disability progression in most subgroups. In SENTINEL, natalizumab significantly reduced the risk of sustained disability progression in the following subgroups: ≥ 9 T2 lesions at baseline, ≥ 1 Gd+ lesions at baseline, female patients and patients < 40 years of age. Natalizumab reduced the risk of disability progression by 64 % and relapse rate by 81 % in treatment- naive patients with highly active disease and by 58 % and 76 %, respectively, in patients with highly active disease despite IFNβ-1a treatment. These results indicate that natalizumab is effective in reducing disability progres- sion and relapses in patients with relapsing MS, particularly in patients with highly active disease.
Multiple Sclerosis Journal | 2012
Christian Confavreux; David Li; Mark S. Freedman; Philippe Truffinet; Hadj Benzerdjeb; Dazhe Wang; Amit Bar-Or; Anthony Traboulsee; Lucy E Reiman; Paul O’Connor
Background: Teriflunomide, an oral disease-modifying therapy in development for patients with relapsing forms of multiple sclerosis (RMS), was well tolerated and effective in reducing magnetic resonance imaging (MRI) lesions in 179 RMS patients in a phase 2 36-week, placebo-controlled study. Methods: A total of 147 patients who completed the core study entered an open-label extension. Teriflunomide patients continued their assigned dose, and placebo patients were re-allocated to teriflunomide, 7 mg/day or 14 mg/day. An interim analysis was performed at a cut-off on January 8 2010. Results: The mean and median duration of study treatment, including both the core and extension phase, from baseline to the interim cut-off, was 5.6 years (standard deviation: 2.7 years) and 7.1 years (range: 0.05–8.5 years), respectively. Of 147 patients, 62 (42.2%) discontinued (19% due to treatment-emergent adverse events (TEAEs)). The most common TEAEs were mild infections, fatigue, sensory disturbances and diarrhoea. No serious opportunistic infections occurred, with no discontinuations due to infection. Asymptomatic alanine aminotransferase increases (≤3× upper limit of normal (ULN)) were common (7 mg, 64.2%; 14 mg, 62.1%); increases >3×ULN were similar across groups (7 mg, 12.3%; 14 mg, 12.1%). Mild decreases in neutrophil counts occurred; none led to discontinuation. The incidence of malignancies was comparable to that of the general population, and cases were not reminiscent of those observed in immunocompromised patients. Annualised relapse rates remained low, minimal disability progression was observed, with a dose-dependent benefit with teriflunomide 14 mg for several MRI parameters. Conclusion: Teriflunomide had a favourable safety profile for up to 8.5 years.
JAMA Neurology | 2012
R. Philip Kinkel; Mariya Dontchev; Craig Kollman; Thomai T. Skaramagas; Paul O’Connor; Jack H. Simon
OBJECTIVE To determine whether immediate initiation of treatment at the time of a clinically isolated syndrome in patients at high risk for clinically definite multiple sclerosis alters disease course over 10 years. DESIGN Prospective follow-up study. SETTING Twenty-four Controlled High-Risk Subjects Avonex Multiple Sclerosis Prevention Study (CHAMPS) sites in the United States and Canada. PARTICIPANTS A total of 81 patients originally randomly assigned to receive intramuscular interferon beta-1a (the immediate-treatment group) and 74 patients originally randomly assigned to receive placebo (the delayed-treatment group). All patients were from CHAMPS. INTERVENTION For the immediate-treatment group, treatment was initiated within a month after the onset of a clinically isolated syndrome, and for the delayed-treatment group, treatment was initiated a median of 30 months (interquartile range, 24-35 months) after CHAMPS randomization. MAIN OUTCOME MEASURES Rate of developing clinically definite multiple sclerosis, annualized relapse rate, disease course classification, disability measures, and magnetic resonance imaging measures. RESULTS The immediate-treatment group showed a lower 10-year rate of clinically definite multiple sclerosis (unadjusted hazard ratio, 0.64 [95% CI, 0.48-0.87]; P = .004) and a lower annualized relapse rate between years 5 and 10 (P = .03). There was no differential effect on disability, magnetic resonance imaging T2-weighted lesions, or the proportion of patients developing progressive disease at 10 years. Few patients reached the Expanded Disability Status Scale milestone scores of 4.0 or greater (9% of patients) or 6.0 or greater (6% of patients). CONCLUSIONS Immediate initiation of intramuscular interferon beta-1a at the time of a clinically isolated syndrome in high-risk patients reduces relapse rates over 10 years but does not improve disability outcomes compared with a control group that also initiated therapy relatively early in the disease course. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00179478.
Multiple Sclerosis Journal | 2014
Gordon Francis; L. Kappos; Paul O’Connor; William Collins; Dejun Tang; F Mercier; Jeffrey Cohen
Background: Reduction in peripheral blood lymphocytes is an expected pharmacodynamic outcome of fingolimod therapy. Objective: The objective of this article is to evaluate lymphocyte dynamics during and after fingolimod therapy and assess the relationship between lymphocyte counts and infections. Methods: Lymphocyte counts and their relationship with infections were evaluated in three multiple sclerosis (MS) populations: (Group A) FREEDOMS phase 3 core study group (n = 1272); (Group B) All Studies group (one phase 2 and two phase 3 studies, plus their extensions; n = 2315); and (Group C) Follow-up group (after fingolimod discontinuation; n = 538). Results: Administration of fingolimod 0.5 mg led to reductions in lymphocyte counts to a steady-state of 24%–30% of baseline values within two weeks, which remained stable while on therapy. Following fingolimod discontinuation, average counts exceeded the lower limit of normal range within six to eight weeks, and were 80% of baseline values by three months. In Group A, infection rates per patient-year were 1.4 with placebo and 1.0 in fingolimod-treated patients who had the lowest lymphocyte counts (< 0.2 × 109/l). No evidence was seen for an increase in serious or opportunistic infections. Conclusions: Fingolimod induces a rapid and reversible reduction in lymphocyte counts without an increase in infections relative to placebo. Because fingolimod reduces blood lymphocyte counts via redistribution in secondary lymphoid organs, peripheral blood lymphocyte counts cannot be utilized to evaluate the lymphocyte subset status of a patient.
Multiple Sclerosis Journal | 2012
Aaron E. Miller; Paul O’Connor; Jerry S. Wolinsky; Christian Confavreux; Ludwig Kappos; Tomas Olsson; Philippe Truffinet; Lin Wang; Laura D’Castro; Giancarlo Comi; Mark S. Freedman
Background: The Teriflunomide Multiple Sclerosis Oral (TEMSO) trial, a randomized, double-blind, placebo-controlled phase III study, demonstrated that teriflunomide significantly reduced annualized relapse rate (ARR), disease progression and magnetic resonance imaging (MRI) activity, with a favorable safety profile in relapsing multiple sclerosis (RMS) patients. Objective: The purpose of this study was to report the effects of teriflunomide on ARR and disability progression in pre-specified subgroups. Methods: RMS patients (n=1088) were randomized to placebo or teriflunomide, 7 mg or 14 mg, once daily, for 108 weeks. Subgroup analyses were performed for ARR and disability progression by baseline demographics (gender, race, age), disease characteristics (Expanded Disability Status Scale (EDSS) strata, relapse history, multiple sclerosis (MS) subtype), MRI parameters (gadolinium-enhancing lesions, total lesion volume) and prior use of MS drugs. A generalized estimating equation method and Cox regression model were used to assess consistency of the treatment effect across subgroups, utilizing a treatment-by-subgroup interaction test for each factor separately. Results: Reductions in ARR and disability progression were consistent across subgroups in favor of teriflunomide, with no treatment-by-subgroup interaction test reaching statistical significance. Conclusion: The positive effects of teriflunomide were demonstrated consistently across subgroups in TEMSO.
JAMA Neurology | 2015
Kathryn C. Fitzgerald; Karl Münger; Karl Köchert; Barry G. W. Arnason; Giancarlo Comi; Stuart D. Cook; Douglas S. Goodin; Massimo Filippi; Hans-Peter Hartung; Paul O’Connor; Gustavo Suarez; Rupert Sandbrink; Ludwig Kappos; Christoph Pohl; Alberto Ascherio
IMPORTANCE Low serum 25-hydroxyvitamin D (25[OH]D) levels are associated with an increased risk of multiple sclerosis (MS) as well as with increased disease activity and rate of progression in clinically isolated syndromes and early MS. OBJECTIVE To assess the association between 25(OH)D and disease course and prognosis in patients with relapsing-remitting MS treated with interferon beta-1b. DESIGN, SETTING, AND PARTICIPANTS We conducted a prospective cohort study assessing 25(OH)D levels and subsequent MS disease course and progression characterized by magnetic resonance imaging (MRI) and clinical end points. The study took place between November 2003 and June 2005; data analysis was performed between June 2013 and December 2014. The study was conducted among participants in the Betaferon Efficacy Yielding Outcomes of a New Dose (BEYOND) study, a large, phase 3, prospective, multicenter, blinded, randomized clinical trial. Patients were monitored for at least 2 years. Clinic visits were scheduled every 3 months, and MRI was performed at baseline and annually thereafter. Eligible patients included 1482 participants randomized to receive 250 μg or 500 μg of interferon-1b with at least 2 measurements of 25(OH)D obtained 6 months apart. EXPOSURES Serum 25(OH)D measurements were performed at baseline, 6 months, and 12 months. MAIN OUTCOMES AND MEASURES Main outcomes included cumulative number of new active lesions (T2 lesions and gadolinium acetate-enhancing lesions), change in normalized brain volume, relapse rate, and progression determined by the Expanded Disability Status Scale (EDSS). Statistical analyses were adjusted for age, sex, randomized treatment, region, disease duration, and baseline EDSS score. RESULTS Overall, average 25(OH)D levels in 1482 patients were significantly inversely correlated with the cumulative number of new active lesions between baseline and the last MRI, with a 50.0-nmol/L increase in serum 25(OH)D levels associated with a 31% lower rate of new lesions (relative rate [RR], 0.69; 95% CI, 0.55-0.86; P = .001). The lowest rate of new lesions was observed among patients with 25(OH)D levels greater than 100.0 nmol/L (RR, 0.53; 95% CI, 0.37-0.78; P = .002). No significant associations were found between 25(OH)D levels and change in brain volume, relapse rates, or EDSS scores. Results were consistent following adjustment for HLA-DRB1*15 or vitamin D-binding protein status. CONCLUSIONS AND RELEVANCE Among patients with MS treated with interferon beta-1b, higher 25(OH)D levels were associated with lower rates of MS activity observed on MRI. Results for brain atrophy and clinical progression were more equivocal.
Immunity | 2015
Natalia Pikor; Jillian L. Astarita; Leslie Summers-Deluca; Georgina Galicia; Joy Qu; Lesley A. Ward; Susan Armstrong; Claudia X. Dominguez; Deepali Malhotra; Brendan Heiden; Robert Kay; Valera Castanov; Hanane Touil; Louis Boon; Paul O’Connor; Amit Bar-Or; Alexandre Prat; Valeria Ramaglia; Samuel K. Ludwin; Shannon J. Turley; Jennifer L. Gommerman
Tertiary lymphoid tissues (TLTs) have been observed in the meninges of multiple sclerosis (MS) patients, but the stromal cells and molecular signals that support TLTs remain unclear. Here, we show that T helper 17 (Th17) cells induced robust TLTs within the brain meninges that were associated with local demyelination during experimental autoimmune encephalitis (EAE). Th17-cell-induced TLTs were underpinned by a network of stromal cells producing extracellular matrix proteins and chemokines, enabling leukocytes to reside within, rather than simply transit through, the meninges. Within the CNS, interactions between lymphotoxin αβ (LTαβ) on Th17 cells and LTβR on meningeal radio-resistant cells were necessary for the propagation of de novo interleukin-17 responses, and activated T cells from MS patients expressed elevated levels of LTβR ligands. Therefore, input from both Th17 cells and the lymphotoxin pathway induce the formation of an immune-competent stromal cell niche in the meninges.
Drug Safety | 2004
Peter Rieckmann; Paul O’Connor; Gordon S. Francis; Graham Wetherill; Enrica Alteri
AbstractIntroduction: Interferon-β-Abstract-1a (Rebif®) is an established treatment for relapsing-remitting multiple sclerosis (MS) and haematological changes are commonly reported in clinical trials of this agent. The combined clinical trial and postmarketing safety database for subcutaneous interferon-β-1a (Rebif®) allows a comprehensive, retrospective assessment of both common and infrequent haematological effects associated with interferon-β therapy. Methods: Haematological laboratory abnormalities were analysed from six randomised, controlled clinical trials of subcutaneous interferon-β-1a in MS, five of which were placebo-controlled. Treatment data were collected from 2482 patients for up to 6 months, 1178 patients for up to 2 years and 786 patients for up to 6 years. Total interferon-β-1a doses ranged from 22μg once weekly to 44μg three times weekly. Postmarketing surveillance data were also analysed. Results: Treatment with interferon-β-1a led to asymptomatic dose-related reductions in all cell lineages under investigation, predominantly white blood cells. The greatest differences between interferon-β-1a therapy and placebo were seen for total leucocyte and neutrophil counts. At least two-thirds of patients affected by cytopenia experienced the onset of cytopenia within the first 6 months of therapy. The majority of events were mild and generally resolved within 3–4 months, while continuing therapy. Dose reductions were uncommon and only a small proportion (6 of 727; 0.8%) of patients stopped treatment over 2 years because of haematological abnormalities when receiving the highest dose of interferon-β-1a, 44μg three times weekly. Postmarketing safety reports were similarly related to asymptomatic cytopenias, although one case of potentially related autoimmune haemolytic anaemia was reported. Conclusion: Although haematological abnormalities are common and dose-related in patients with MS receiving interferon-β-1a, the events are mainly mild and transient, with little impact on adherence to therapy. Haematological events are rarely of clinical significance and do not adversely affect the benefit-to-risk ratio that favours high-dose interferon-β-1a therapy.
Multiple Sclerosis Journal | 2013
Jerry S. Wolinsky; Ponnada A. Narayana; Flavia Nelson; Sushmita Datta; Paul O’Connor; Christian Confavreux; Giancarlo Comi; Ludwig Kappos; Tomas Olsson; Philippe Truffinet; Lin Wang; Aaron E. Miller; Mark Freedman
Objective: The purpose of this study was to determine the effects of oral teriflunomide on multiple sclerosis (MS) pathology inferred by magnetic resonance imaging (MRI). Methods: Patients (n=1088) with relapsing MS were randomized to once-daily teriflunomide 7 mg or 14 mg, or placebo, for 108 weeks. MRI was recorded at baseline, 24, 48, 72 and 108 weeks. Annualized relapse rate and confirmed progression of disability (sustained ≥12 weeks) were the primary and key secondary outcomes. The principal MRI outcome was change in total lesion volume. Results: After 108 weeks, increase in total lesion volume was 67.4% (p=0.0003) and 39.4% (p=0.0317) lower in the 14 and 7 mg dose groups versus placebo. Other measures favoring teriflunomide were accumulated enhanced lesions, combined unique activity, T2-hyperintense and T1-hypointense component lesion volumes, white matter volume, and a composite MRI score; all were significant for teriflunomide 14 mg and most significant for 7 mg versus placebo. Conclusions: Teriflunomide provided benefits on brain MRI activity across multiple measures, with a dose effect evident on several markers. These effects were also consistent across selected subgroups of the study population. These findings complement clinical data showing significant teriflunomide-related reductions in relapse rate and disease progression, and demonstrate containment of MRI-defined disease progression.
Multiple Sclerosis Journal | 2011
Xavier Montalban; Giancarlo Comi; Paul O’Connor; Sm Gold; A. de Vera; B Eckert; L. Kappos
Background: Health-related quality of life (HRQoL) worsens with multiple sclerosis (MS) relapses and disease progression. Common symptoms including depression and fatigue may contribute to poor HRQoL. Objectives: To report exploratory analyses assessing the impact of fingolimod (FTY720) on HRQoL and depression in a phase II study of relapsing MS. Methods: The Hamburg Quality of Life Questionnaire in MS (HAQUAMS) and Beck Depression Inventory second edition (BDI-II) scores were assessed during a 6-month, placebo-controlled study and optional extension. Results: HAQUAMS total score improved with fingolimod and worsened with placebo. Mean score change from baseline to month 6 was −0.02 with fingolimod 1.25 mg (p < 0.05 versus placebo), −0.01 with fingolimod 5.0 mg and + 0.12 with placebo. Categorical data supported a clinically important effect of fingolimod on HRQoL. Fingolimod 1.25 mg was also beneficial over placebo in the fatigue/thinking HAQUAMS sub-domain (p < 0.05 versus placebo). Change in mean BDI-II scores from baseline to month 6 and the proportion of patients with BDI-II scores indicative of clinical depression favored fingolimod 1.25 mg over placebo (p < 0.05 for both). At month 4, mean BDI-II and HAQUAMS total scores appeared to be maintained in fingolimod-treated patients. Conclusion: Fingolimod 1.25 mg may improve HRQoL and depression at 6 onths compared with placebo in patients with relapsing MS.