Natalizumab effectively prevents disease activity in relapsing-remitting multiple sclerosis, but many treated patients report subjective wearing-off symptoms at the end of the 4-week interval between infusions. Extended interval dosing (EID) is a promising strategy to mitigate the risk of natalizumab-associated progressive multifocal leukoencephalopathy, but it is unknown whether EID affects wearing-off symptoms. In this observational study, we evaluated if prevalence or intensity of wearing-off symptoms changed when natalizumab dosing intervals were extended from 4 to 6 weeks in 30 treated patients during the outbreak of COVID-19 in Norway. New or increased wearing-off symptoms during EID were reported by 50%. Symptom increase was more frequent among patients with pre-existing wearing-off symptoms during standard dosing compared to patients without such pre-existing symptoms [p = 0.0005]. Our observations support the need to study the effect of EID on wearing-off symptoms in randomized controlled trials.

那他珠单抗可有效预防复发-缓解型多发性硬化症的疾病活动，但许多接受治疗的患者在输注 4 周间隔结束时报告出现主观消退症状。延长间隔给药 (EID) 是减轻那他珠单抗相关进行性多灶性脑白质病风险的一种有前途的策略，但尚不清楚 EID 是否会影响逐渐消失的症状。在这项观察性研究中，我们评估了在挪威 COVID-19 爆发期间，当 30 名接受治疗的患者将那他珠单抗给药间隔从 4 周延长至 6 周时，消退症状的患病率或强度是否发生了变化。50% 报告了 EID 期间出现新的或增加的磨损症状。p  = 0.0005]。我们的观察结果支持在随机对照试验中研究 EID 对消退症状的影响的必要性。