Stopping Disease-Modifying Treatments in Multiple Sclerosis: A Systematic Review and Meta-Analysis of Real-World Studies.

BACKGROUND: The question of whether multiple sclerosis requires life-long disease-modifying treatments (DMTs) remains unanswered. Some studies suggest that older patients with stable disease may safely discontinue their DMTs, yet comprehensive evidence-based data are scarce and real-world studies have provided mixed results.

OBJECTIVE: The aim of this study was to assess the rate of disease reactivation and associated risk factors after discontinuation of DMTs in patients with multiple sclerosis.

METHODS: We searched scientific databases (PubMed/MEDLINE, Scopus and Google Scholar) to identify real-world studies published until 31 July, 2023 that reported the number of patients who experienced relapses and/or disability accrual (outcomes of interest) following a therapy discontinuation longer than 12 months. Magnetic resonance activity and treatment re-start after DMT discontinuation were also considered as additional outcomes. We excluded studies where therapy discontinuation was explicitly related to an unintended or planned pregnancy or preceded a treatment switch. We ran random-effects meta-analyses, subgroup analyses and meta-regression models to provide pooled estimates of post-discontinuation relapse and disability events, and to identify their potential moderators (predictors).

RESULTS: After an independent screening, 22 articles met the eligibility criteria, yielding a pooled sample size of 2942 patients followed for 1-7 years after discontinuation (11,689 patient-years). The pooled rates for relapse and disability events were 6.7 and 5.8 per 100 patient-years, respectively. However, available data did not allow us to disentangle isolated disability accrual from relapse-associated worsening. Studies including older patients (β = -0.65, p = 0.006), patients with a longer exposure to DMTs (β = -2.22, p = 0.001) and patients with a longer period of disease stability (β = -2.74, p = 0.002) showed a lower risk of relapse events. According to meta-regression equations, the risk of relapse events after DMT discontinuation became negligible (arbitrarily set at < 1% per year) at approximately 60 years of age, and after either 10 years of DMT exposure, or 8 years of disease stability. Additional analyses showed pooled rates for magnetic resonance imaging activity and re-start events of 16.7 and 17.5 per 100 patient-years, respectively.

CONCLUSIONS: Based on our quantitative synthesis of real-world data, in the absence of definitive answers from clinical trials, DMT discontinuation appears feasible with a high degree of certainty in selected patients. While our findings are robust regarding relapse events, future efforts are warranted to determine if DMT discontinuation is associated with isolated disability accrual.