ObjectiveTo test the hypothesis that immunotherapy prevents long-term disability in relapsing-remitting multiple sclerosis, we modelled disability outcomes in 14,717 patients.MethodsWe studied patients from MSBase followed for ≥1 year, with ≥3 visits, ≥1 visit per year and exposed to a multiple sclerosis therapy, and a subset of patients with ≥15-year follow-up. Marginal structural models were used to compare the hazard of 12-month confirmed increase and decrease in disability, EDSS step 6 and the incidence of relapses between treated and untreated periods. Marginal structural models were continuously re-adjusted for patient age, sex, pregnancy, date, disease course, time from first symptom, prior relapse history, disability and MRI activity.Results14,717 patients were studied. During the treated periods, patients were less likely to experience relapses (hazard ratio 0.60, 95% confidence interval 0.43–0.82, p = 0.0016), worsening of disability (0.56, 0.38–0.82, p = 0.0026) and progress to EDSS step 6 (0.33, 0.19–0.59, p = 0.00019). Among 1,085 patients with ≥15-year follow-up, the treated patients were less likely to experience relapses (0.59, 0.50–0.70, p = 10−9) and worsening of disability (0.81, 0.67–0.99, p = 0.043).ConclusionsContinued treatment with multiple sclerosis immunotherapies reduces disability accrual by 19%–44% (95%CI 1%–62%), the risk of need of a walking aid by 67% (95%CI 41%–81%) and the frequency of relapses by 40–41% (95%CI 18%–57%) over 15 years. This study provides the evidence that disease modifying therapies are effective in improving disability outcomes in relapsing-remitting multiple sclerosis over the long-term.Classification of evidenceThis study provides class IV evidence that for patients with relapsing-remitting multiple sclerosis, long-term exposure to immunotherapy prevents neurological disability.

Background: The risk factors for conversion from relapsing-remitting to secondary progressive multiple sclerosis remain highly contested. Objective: The aim of this study was to determine the demographic, clinical and paraclinical features that influence the risk of conversion to secondary progressive multiple sclerosis. Methods: Patients with adult-onset relapsing–remitting multiple sclerosis and at least four recorded disability scores were selected from MSBase, a global observational cohort. The risk of conversion to objectively defined secondary progressive multiple sclerosis was evaluated at multiple time points per patient using multivariable marginal Cox regression models. Sensitivity analyses were performed. Results: A total of 15,717 patients were included in the primary analysis. Older age (hazard ratio (HR) = 1.02, p < 0.001), longer disease duration (HR = 1.01, p = 0.038), a higher Expanded Disability Status Scale score (HR = 1.30, p < 0.001), more rapid disability trajectory (HR = 2.82, p < 0.001) and greater number of relapses in the previous year (HR = 1.07, p = 0.010) were independently associated with an increased risk of secondary progressive multiple sclerosis. Improving disability (HR = 0.62, p = 0.039) and disease-modifying therapy exposure (HR = 0.71, p = 0.007) were associated with a lower risk. Recent cerebral magnetic resonance imaging activity, evidence of spinal cord lesions and oligoclonal bands in the cerebrospinal fluid were not associated with the risk of conversion. Conclusion: Risk of secondary progressive multiple sclerosis increases with age, duration of illness and worsening disability and decreases with improving disability. Therapy may delay the onset of secondary progression.

BackgroundEarly markers of axonal and clinical outcomes are required for early phase testing of putative neuroprotective therapies for multiple sclerosis (MS). ObjectivesTo assess whether early measurement of diffusion tensor imaging (DTI) parameters (axial and radial diffusivity) within the optic nerve during and after acute demyelinating optic neuritis (ON) could predict axonal (retinal nerve fibre layer thinning and multi-focal visual evoked potential amplitude reduction) or clinical (visual acuity and visual field loss) outcomes at 6 or 12 months. MethodsThirty-seven patients presenting with acute, unilateral ON were studied at baseline, one, three, six and 12 months using optic nerve DTI, clinical and paraclinical markers of axonal injury and clinical visual dysfunction. ResultsAffected nerve axial diffusivity (AD) was reduced at baseline, 1 and 3 months. Reduced 1-month AD correlated with retinal nerve fibre layer (RNFL) thinning at 6 (R=0.38, p=0.04) and 12 months (R=0.437, p=0.008) and VEP amplitude loss at 6 (R=0.414, p=0.019) and 12 months (R=0.484, p=0.003). AD reduction at three months correlated with high contrast visual acuity at 6 (ρ = -0.519, p = 0.001) and 12 months (ρ = -0.414, p=0.011). The time-course for AD reduction for each patient was modelled using a quadratic regression. AD normalised after a median of 18 weeks and longer normalisation times were associated with more pronounced RNFL thinning and mfVEP amplitude loss at 12 months. Affected nerve radial diffusivity (RD) was unchanged until three months, after which time it remained elevated. ConclusionsThese results demonstrate that AD reduces during acute ON. One month AD reduction correlates with the extent of axonal loss and persistent AD reduction at 3 months predicts poorer visual outcomes. This suggests that acute ON therapies that normalise optic nerve AD by 3 months could also promote axon survival and improve visual outcomes.

Following the availability of fingolimod, patients were more likely to discontinue injectable treatments. Those who switched to fingolimod were more likely to do so for convenience. Persistence was improved on fingolimod compared to other medications.

Background/objective: Observational clinical data from cladribine-treated patients with relapsing forms of multiple sclerosis (MS) were recorded in the Australian MS registry powered by the MSBase registry platform (5-year follow-up) and analysed to complement information from the pivotal cladribine clinical trials in MS. Methods: A cohort of 90 cladribine-treated patients with follow-up data reported by treating physicians and recorded in the Australian MSBase registry (database lock February 2016) were examined. Clinical data included Expanded Disability Status Scale (EDSS) scores, relapses and other disease-modifying drugs (DMDs) administered before and after cladribine treatment. Results: Mean age on starting cladribine was 47 years; mean age at MS onset was 34 years, and median baseline EDSS score was 5.25. Disability trajectories in patients with sufficient follow-up suggested an overall increasing trend prior to cladribine treatment which was reduced during the 2-year post-treatment. Approximately 80% of patients were EDSS progression-free, 65% remained relapse-free after 2 years and median time to next DMD was 1.7 years. Conclusion: These observational data suggest a disease-modifying effect in this cohort of relapsing MS patients characterised by older and more disabled patients. Since these data represent a single-arm cohort, clinical trials and larger comparative post-marketing studies are needed to validate and extend these findings.