RESUMEN
Importance: Understanding the association between clinically defined relapses and radiological activity in multiple sclerosis (MS) is essential for patient treatment and therapeutic development. Objective: To investigate clinical events identified as relapses but not associated with new T2 lesions or gadolinium-enhanced T1 lesions on brain and spinal cord magnetic resonance imaging (MRI). Design, Setting, and Participants: This multicenter observational cohort study was conducted between January 2015 and June 2023. Data were extracted on June 8, 2023, from the French MS registry. All clinical events reported as relapses in patients with relapsing-remitting MS were included if brain and spinal cord MRI was performed within 12 and 24 months before the event, respectively, and 50 days thereafter with gadolinium injection. Exposures: Events were classified as relapses with active MRI (RAM) if a new T2 lesion or gadolinium-enhanced T1 lesion appeared on brain or spinal cord MRI or as acute clinical events with stable MRI (ACES) otherwise. Main Outcomes and Measures: Factors associated with ACES were investigated; patients with ACES and RAM were compared regarding Expanded Disability Status Scale (EDSS) course, relapse rate, confirmed disability accrual (CDA), relapse-associated worsening (RAW), progression independent of relapse activity (PIRA), and transition to secondary progressive (SP) MS, and ACES and RAM rates under each disease-modifying therapy (DMT) were estimated. Results: Among 31â¯885 clinical events, 637 in 608 patients (493 [77.4%] female; mean [SD] age, 35.8 [10.7] years) were included. ACES accounted for 166 (26.1%) events and were more likely in patients receiving highly effective DMTs, those with longer disease duration (odds ratio [OR], 1.04; 95% CI, 1.01-1.07), or those presenting with fatigue (OR, 2.14; 95% CI, 1.15-3.96). ACES were associated with significant EDSS score increases, lower than those found for RAM. Before the index event, patients with ACES experienced significantly higher rates of relapse (relative rate [RR], 1.21; 95% CI, 1.01-1.46), CDA (hazard ratio [HR], 1.54; 95% CI, 1.13-2.11), and RAW (HR, 1.72; 95% CI, 1.20-2.45). Patients with ACES were at significantly greater risk of SP transition (HR, 2.58; 95% CI, 1.02-6.51). Although RAM rate decreased with DMTs according to their expected efficacy, ACES rate was stable across DMTs. Conclusions and Relevance: The findings in this study introduce the concept of ACES in MS, which accounted for one-fourth of clinical events identified as relapses.
RESUMEN
Importance: A recent randomized clinical trial concluded that discontinuing medium-efficacy therapy might be a reasonable option for older patients with nonactive multiple sclerosis (MS), but there is a lack of data on discontinuing high-efficacy therapy (HET). In younger patients, the discontinuation of natalizumab and fingolimod is associated with a risk of rebound of disease activity. Objective: To determine whether discontinuing HET in patients 50 years and older with nonactive MS is associated with an increased risk of relapse compared with continuing HET. Design, Setting, and Participants: This observational cohort study used data from 38 referral centers from the French MS registry (Observatoire Français de la Sclérose en Plaques [OFSEP] database). Among 84704 patients in the database, data were extracted for 1857 patients 50 years and older with relapsing-remitting MS treated by HET and with no relapse or magnetic resonance imaging activity for at least 2 years. After verification of the medical records, 1620 patients were classified as having discontinued HET or having remained taking treatment and were matched 1:1 using a dynamic propensity score (including age, sex, disease phenotype, disability, treatment of interest, and time since last inflammatory activity). Patients were included from February 2008 to November 2021, with a mean (SD) follow-up of 5.1 (2.9) years. Data were extracted in June 2022. Exposures: Natalizumab, fingolimod, rituximab, and ocrelizumab. Main Outcomes and Measures: Time to first relapse. Results: Of 1620 included patients, 1175 (72.5%) were female, and the mean (SD) age was 54.7 (4.8) years. Among the 1452 in the HET continuation group and 168 in the HET discontinuation group, 154 patients in each group were matched using propensity scores (mean [SD] age, 57.7 [5.5] years; mean [SD] delay since the last inflammatory activity, 5.6 [3.8] years; mean [SD] follow-up duration after propensity score matching, 2.5 [2.1] years). Time to first relapse was significantly reduced in the HET discontinuation group compared with the HET continuation group (hazard ratio, 4.1; 95% CI, 2.0-8.5; P < .001) but differed between HETs, with a hazard ratio of 7.2 (95% CI, 2.1-24.5; P = .001) for natalizumab, 4.5 (95% CI, 1.3-15.5; P = .02) for fingolimod, and 1.1 (95% CI, 0.3-4.8; P = .85) for anti-CD20 therapy. Conclusion and Relevance: As in younger patients, in patients 50 years and older with nonactive MS, the risk of relapse increased significantly after stopping HETs that impact immune cell trafficking (natalizumab and fingolimod). There was no significant increase in risk after stopping HETs that deplete B-cells (anti-CD20 therapy). This result may inform decisions about stopping HETs in clinical practice.
