Disease-modifying drugs can reduce disability progression in relapsing multiple sclerosis

Area of Science:

• Neurology
• Clinical Pharmacology

Background:

• Multiple sclerosis (MS) treatments are increasingly available, but real-world patient populations differ from clinical trials, particularly regarding age.
• Extreme age groups are often under-represented in pivotal MS drug studies.

Purpose of the Study:

• To evaluate disease-modifying drug (DMD) treatment exposure and its effect on disability progression in paediatric-onset, adult-onset, and late-onset multiple sclerosis patients.
• To assess the risk of disability worsening and sustained Expanded Disability Status Scale (EDSS) scores based on age and DMD exposure.

Main Methods:

• A multicentre, observational, retrospective Italian cohort study of relapsing-remitting MS patients.
• Analysis included patients with ≥5 years follow-up, ≥3 EDSS evaluations, and early neurological evaluation.
• Multivariate Cox regression models assessed the risk of 12-month confirmed disability worsening and sustained EDSS 4.0, analyzing DMD effect by time exposure quartiles.

Main Results:

• DMDs reduced the risk of 12-month confirmed disability worsening in paediatric-onset (aHR 8.0) and adult-onset (aHR 6.3) patients, with a trend in late-onset patients (aHR 1.9).
• A progressive risk reduction was observed with increased DMD exposure (quartiles).
• Relapses were a risk factor for worsening; female sex showed a protective role in late-onset MS.

Conclusions:

• Sustained exposure to DMDs decreases disability accumulation in MS patients, appearing to be dose-dependent.
• DMD effectiveness is lower but still detectable in late-onset MS patients compared to younger cohorts.