Should I stop or should I go on? Disease modifying therapy after the first clinical episode of multiple sclerosis.

INTRODUCTION Treatment with disease-modifying therapies (DMT) in patients with clinically isolated syndrome (CIS) represents standard care in multiple sclerosis (MS) patients nowadays. Since a proportion of patients may show no evidence of disease activity (NEDA) after some time of treatment, the question might arise about the risks of stopping DMT. METHODS We present a cohort of 49 patients who started DMT immediately after CIS and had no evidence of disease activity (NEDA-3) for at least five years before discontinuation of therapy. Thereafter, patients underwent clinical and MRI follow-up for at least five consecutive years. RESULTS Of 49 patients discontinuing DMT, 53% (n = 26) had NEDA for at least further five years, while 47% (n = 23) showed either a relapse/disease progression (18.4%, n = 9), MRI activity (14.3%, n = 7) or both (14.3%, n = 7). The main predictive factor for sustained NEDA was age at DMT termination. Patients aged > 45 years had a significantly lower risk of disease reactivation (13% vs. 54% in patients aged < 45 years, p < 0.001) after DMT discontinuation. DISCUSSION In CIS patients with immediate DMT after their first clinical episode, older age at the time of DMT discontinuation is the main predictive factor for sustained NEDA status.