Accounting for disease modifying therapy in models of clinical progression in multiple sclerosis

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.

Predictors of disability worsening in clinically isolated syndrome

Objective

To assess demographic, clinical, magnetic resonance imaging, and treatment exposure predictors of time to 3 or 12-month confirmed disability worsening in clinically isolated syndrome (CIS) and early multiple sclerosis (MS).

Methods

We utilized the MSBase Incident Study (MSBasis), a prospective cohort study of outcome after CIS. Predictors of time to first 3 and 12-month confirmed expanded disability status scale worsening were analyzed using Cox proportional hazards regression.

Results

About 1989 patients were analyzed, the largest seen-from-onset cohort reported to-date. A total of 391 patients had a first 3-month confirmed disability worsening event, of which 307 were sustained for 12 months. Older age at CIS onset (adjusted hazard ratio: aHR 1.17, 95% 1.06, 1.30), pyramidal (aHR 1.45, 95% CI 1.13, 1.89) and ambulation (HR 1.60, 95% CI 1.09, 2.34) system dysfunction, annualized relapse rate (aHR 1.20, 95% CI 1.18, 1.22), and lower proportion of observation time on treatment were associated with 3-month confirmed worsening. Predictors of time to 12-month sustained worsening included pyramidal system dysfunction (Hazard ratio: aHR 1.38, 95% CI 1.05, 1.83), and older age at CIS onset (aHR 1.17, 95% CI 1.04, 1.31). Greater proportion of follow-up time exposed to treatment was associated with greater reductions in the rate of worsening.

Interpretation

This study provides class IV evidence for a strong protective effect of disease-modifying treatment to reduce disability worsening events in patients with CIS and early MS, and confirms age and pyramidal dysfunction at onset as risk factors.

Effect of gender on late-onset multiple sclerosis

Objectives:

We aimed to examine the incidence and disease course of late-onset multiple sclerosis (LOMS) compared with adult-onset MS (AOMS) in our clinic cohort, stratified based on gender and race, since both have been reported as important modifiers of disease outcomes in MS.

Methods:

Patients with LOMS and AOMS were compared in terms of demographic characteristics and disease course characteristics. Combined effects were investigated with a logistic regression model. Time from disease onset to sustained Expanded Disability Status Scale (EDSS) score of 6 was investigated using an extension of log-rank test appropriate for interval-censored data.

Results:

Some 7.96% of 4273 patients studied had an onset of MS after the age of 50 years (LOMS), and 1.33% experienced an onset after age 60. Progressive onset was more common in LOMS relative to AOMS. The proportion of women with progressive-onset disease was similar in AOMS and LOMS. Time to EDSS 6 was delayed in AOMS females compared with males; however, it was similar between males and females in the LOMS group.

Conclusions:

Women with LOMS have a different trajectory in terms of disease progression than women with AOMS. The effect of menopause combined with race/ethnicity on the MS disease course requires further investigation.

Tyrosine kinase inhibitors ameliorate autoimmune encephalomyelitis in a mouse model of multiple sclerosis

Multiple sclerosis is an autoimmune disease of the central nervous system characterized by neuroinflammation and demyelination. Although considered a T cell-mediated disease, multiple sclerosis involves the activation of both adaptive and innate immune cells, as well as resident cells of the central nervous system, which synergize in inducing inflammation and thereby demyelination. Differentiation, survival, and inflammatory functions of innate immune cells and of astrocytes of the central nervous system are regulated by tyrosine kinases. Here, we show that imatinib, sorafenib, and GW2580-small molecule tyrosine kinase inhibitors-can each prevent the development of disease and treat established disease in a mouse model of multiple sclerosis. In vitro, imatinib and sorafenib inhibited astrocyte proliferation mediated by the tyrosine kinase platelet-derived growth factor receptor (PDGFR), whereas GW2580 and sorafenib inhibited macrophage tumor necrosis factor (TNF) production mediated by the tyrosine kinases c-Fms and PDGFR, respectively. In vivo, amelioration of disease by GW2580 was associated with a reduction in the proportion of macrophages and T cells in the CNS infiltrate, as well as a reduction in the levels of circulating TNF. Our findings suggest that GW2580 and the FDA-approved drugs imatinib and sorafenib have potential as novel therapeutics for the treatment of autoimmune demyelinating disease.