To describe the clinical characteristics of older people with multiple sclerosis (pwMS), proportion and reasons for older pwMS to discontinue disease-modifying therapy (DMT), and rates of clinical and MRI disease activity after discontinuation.

Older pwMS were identified from the St. Michael’s Hospital MS Clinic Registry from 06/2015-04/2024. Demographics, clinical characteristics, DMT discontinuation data, and clinical (relapses, disability progression) and radiographical (new/enlarging T2 lesions on sequential MRIs) activity after DMT discontinuation were extracted.

Of 1828 pwMS, 14% (n=253) discontinued a DMT after age 55 at mean age of 61.3 (SD=5) years and were then followed for 7.9 (SD=4) years. The most common DMTs discontinued among older pwMS were interferon beta agents (n=104, 41%) and glatiramer acetate (n=54, 21%). The most common reasons for discontinuation were transition to secondary progressive MS (n=58, 23%), choice/convenience (n=41, 16%), and tolerability concerns (n=36, 14%). Following discontinuation, 14% (n=35) pwMS had a clinical relapse, and 31% (n=49/160) had MRI disease activity.

At our center, a small proportion of older pwMS discontinued DMTs after age 55, mainly due to transition to progressive disease, preference, and tolerability concerns. Few relapses and new/enlarging lesions on MRI were reported after discontinuation. Our real-world findings suggest that DMT discontinuation in older pwMS may be a reasonable strategy, potentially impacting future MS management in older patients. Future studies of older pwMS at diverse geographic regions are needed to assess the risk and benefits of discontinuing a wider range of DMTs.