Diminishing returns of disease-modifying treatment in older participants of multiple sclerosis clinical trials. - Strijbis E; Mostert J; D'Haeseleer M; Moral E; Brieva Ruiz L; Comtois J; Killestein J; Repovic P; McPherson T; Cutter G; Koch M (Multiple sclerosis (Houndmills, Basingstoke, England), 2026)