De-escalating rituximab dose results in stability of clinical, radiological, and serum neurofilament levels in multiple sclerosis.

BACKGROUND: Phase II and observational studies support the use of rituximab in multiple sclerosis. Standard protocols are lacking, but studies suggest comparable efficacy between low- and high-dose regimens. OBJECTIVE: To evaluate effectiveness and safety of de-escalating rituximab dose from 1000 to 500 mg/6 months in multiple sclerosis. METHODS: Patients were switched from rituximab 1000 to 500 mg/6 months and prospectively followed for 12 months. Relapses, disability, occurrence of brain/spinal magnetic resonance imaging (MRI) lesions, serum neurofilament light chain (NfL), CD19+ B cell, and IgG concentrations were analyzed. RESULTS: Fifty-nine patients were included (37 relapsing-remitting, 22 secondary progressive). No relapses occurred, with no difference in expanded disability status scale (EDSS) between baseline (4 (2.5-4.5) and 12 months (3.5 (2.5-5.5) p = 0.284). Overall, three new T2 lesions appeared during follow-up. NfL concentration was stable between baseline (7.9 (5.9-45.2) pg/mL) and 12 months (9.1 (5.9-21.3) pg/mL, p = 0.120). IgG concentrations decreased with greater rituximab load (coefficient = -0.439, p = 0.041). IgG deficient patients had greater risk of infections (OR = 6.27, 95% CI = 1.71-22.9, p = 0.005). CONCLUSION: De-escalating rituximab dose from 1000 to 500 mg/6 months is safe, results in clinical and radiological stability, and does not affect serum NfL over 12 months. Rituximab load negatively influences IgG concentrations, and IgG deficient patients are at higher risk of infections.

Association of Rituximab Treatment With Disability Progression Among Patients With Secondary Progressive Multiple Sclerosis.

Importance: Therapeutic options for patients with secondary progressive multiple sclerosis (SPMS) are limited. Objective: To analyze disability progression in patients with SPMS treated with rituximab compared with matched control patients never treated with rituximab. Design, Setting, and Participants: This retrospective cohort study analyzed data obtained from patients with SPMS at 3 multiple sclerosis centers located in Basel and Lugano, Switzerland, and Amsterdam, the Netherlands, from 2004 to 2017. Patients were included for analysis if they had received a diagnosis of SPMS, were treated (57 eligible; 54 included) or never treated (504 eligible; 59 included) with rituximab, and had at least 1 follow-up visit. The variables used for propensity score matching were sex, age, Expanded Disability Status Scale (EDSS) score, and disease duration. Follow-up duration was up to 10 years, with a mean (SD) of 3.5 (2.6) years for rituximab-treated patients and 5.4 (2.4) years for controls in the total cohort and a mean (SD) of 3.5 (2.7) years for rituximab-treated patients and 4.8 (2.2) years for controls in the matched cohort. Exposures: Comparing EDSS score progression in patients with SPMS (treated with rituximab vs not treated with rituximab) using propensity score matching. Main Outcomes and Measures: The primary end point was progression of EDSS score after baseline, and the secondary end point was time to confirmed disability progression. Results: After 1:1 propensity score matching, 44 matched pairs (88 patients) were included in the analysis. At baseline, patients treated with rituximab had a mean (SD) age of 49.7 (10.0) years, mean (SD) disease duration of 18.2 (9.4) years, and mean (SD) EDSS score of 5.9 (1.4), and 26 (59%) were women, whereas controls had a mean (SD) age of 51.3 (7.4) years, mean (SD) disease duration of 19.4 (8.7) years, and mean (SD) EDSS score of 5.70 (1.29), and 27 (61%) were women. In the covariate-adjusted analysis of the matched set, patients with SPMS who were treated with rituximab had a significantly lower EDSS score during a mean (SD) follow-up of 3.5 (2.7) years (mean difference, -0.52; 95% CI, -0.79 to -0.26; P < .001). Time to confirmed disability progression was significantly delayed in the rituximab-treated group (hazard ratio, 0.49; 95% CI, 0.26-0.93; P = .03). Conclusions and Relevance: In this study, patients with SPMS treated with rituximab had a significantly lower EDSS score for up to 10 years of follow-up and a significantly delayed confirmed progression compared with matched controls, suggesting that B-cell depletion by rituximab may be therapeutically beneficial in these patients. A prospective randomized clinical trial with a better level of evidence is needed to confirm the efficacy of rituximab in such patients.

Effectiveness and safety of Rituximab in multiple sclerosis: an observational study from Southern Switzerland.

BACKGROUND: Despite positive results from phase II and observational studies, Rituximab (RTX) is not currently approved for multiple sclerosis (MS) treatment and can only be used off-label. OBJECTIVE: To characterize MS patients treated with RTX and investigate its effectiveness and safety in a clinical practice setting. METHODS: Observational analysis of data collected from MS patients at the Neurocenter of Southern Switzerland. Relapses, EDSS worsening, MRI lesion accrual and "evidence of disease activity" (EDA) status were described by Cox regression. RTX and natalizumab treated patients were matched by propensity scores. RESULTS: Out of 453 MS patients, 82 were treated with RTX, 43 (52.4%) relapsing-remitting (RRMS) and 39 (47.6%) progressive MS (median age = 48 [40-54] years, females n = 60 [73.2%], EDSS = 4.0 [2.5-6.0], median follow-up = 1.5 [1.0-2.5] years). Three relapses occurred and 59 (75.6%) patients had not EDA at follow-up end. Time to EDA was similar in RTX and natalizumab treated RRMS patients (HR = 1.64, 95%CI = 0.46-5.85, p = 0.44). Twenty-four patients presented non infusion related adverse events (infections), requiring RTX discontinuation in 6 individuals. CONCLUSION: These results provide further evidence for RTX being effective in MS treatment, to a similar extent to natalizumab in RRMS. Clinicians must be vigilant for the potential occurrence of infections.