Recurring disease activity in relapsing remitting multiple sclerosis: The multicenter RDA-RMS study.

Background: This study investigates the gap in understanding the dynamics of recurring disease activity (RDA) in RRMS patients after fingolimod (FGL) treatment discontinuation. The aim is to investigate RDA in RRMS patients after stopping FGL, aiming to improve management and comprehension of disease progression post-treatment.

Methods: In this multicenter, retrospective study, data from 172 of 944 RRMS patients aged 18-55, across nine centers in Turkey, who discontinued FGL treatment, were analyzed. The collected data included EDSS scores, annualized relapse rates (ARR), lymphocyte counts, and MRI findings, with follow-up assessments conducted at 6 months, 1 year, and up to 2 years.

Results: RDA was observed in 31.9 % of patients, with incidences of rebound and reactivation at 20.3 % and 11.6 %, respectively. Factors like younger age, longer treatment duration, lower lymphocyte counts, and higher lesion burden increased RDA risk. Notably, 52.9 % of pregnant patients experienced RDA (16.4 % of the overall RDA group), with rebound occurring in six and reactivation in three. Patients with RDA had longer medication-free intervals and increased ARR. Discontinuation reasons varied, with disease progression linked to a lower RDA risk.

Conclusion: Findings highlight the necessity for personalized management and vigilant monitoring after FGL discontinuation in RRMS patients, offering critical insights into RDA risk factors, and the complex interplay between treatment cessation, pregnancy, and disease progression.