Impact of multiple sclerosis disease-modifying therapies on chronic lesion tissue expansion.

BACKGROUND

Chronic lesion tissue expansion (CLTE) reflects slow, concentric growth of established multiple sclerosis (MS) lesions and is linked to central brain atrophy and disability progression. Whether existing MS disease-modifying therapies (DMTs) differentially influence this aspect of progressive MS biology remains unclear.

OBJECTIVES

To compare the effect of current DMTs on CLTE in a multicentre, real-world MS cohort.

METHODS

We conducted a retrospective, observational study using linked clinical data from MSBase and the MSBase Imaging Repository. Data from patients aged ⩾18 years with ⩾3 longitudinal MRI scans, and 7 therapies with ⩾100 stable treatment epochs were included. Therapy effects on CLTE, new T2 lesions, and brain atrophy were assessed using epoch-based covariate-adjusted generalised estimating equation models, with fingolimod as a comparator.

RESULT: The cohort included 564 patients contributing 1648 stable treatment epochs. After adjustment for demographic, clinical, and imaging covariates, B-cell depleting therapy was the only DMT associated with significantly lower CLTE (β = -4.03, p = 0.017) relative to fingolimod. CLTE was independently associated with age, baseline lesion volume, and centre effects.

CONCLUSIONS

B-cell depletion is associated with reduced CLTE, a promising biomarker of progressive MS biology.