Abstract
This study assesses the outcomes of immunotherapy discontinuation in patients with relapsing seronegative idiopathic myelitis (SIM), a condition that remains uninvestigated due to its rarity. We reviewed records from 77 patients with relapsing SIM at the National Cancer Center of Korea, focusing on 11 who discontinued treatment after a median relapse-free period of over 5 years. Notably, all patients remained relapse-free for a median of 36.5 months following discontinuation. Our findings suggest that immunotherapy discontinuation can be a feasible therapeutic strategy for selected patients who have maintained a prolonged relapse-free period.