Treatment patterns of patients with neuromyelitis optica spectrum disorder switched to inebilizumab in Japan: a claims-based retrospective study

Abstract Background In Japan, several biological agents with distinct mechanisms of action are available for the prevention of relapse in neuromyelitis optica spectrum disorder (NMOSD), including the B cell-depleting agent inebilizumab. Understanding the management of transitions between these agents is crucial for exploring safe switching strategies. This study examined real-world treatment patterns among patients who transitioned from non-inebilizumab biological agents to inebilizumab utilizing a claims database in Japan. Results Among the overall population of patients with NMOSD prescribed inebilizumab ( n = 134), 19.4% ( n = 26) transitioned from non-inebilizumab biological agents. Among these 26 patients, the median duration from the last prescription of the previous biological agent to the first inebilizumab prescription, designated as the index date, was 16 days for eculizumab (five patients), 48 days for satralizumab (16 patients), 56 days for ravulizumab (three patients), and 168 and 177 days for two patients treated with rituximab. Regarding oral glucocorticoid (GC) prescriptions in the switching population, the distribution of doses among patients shifted toward higher categories around the index date. The proportion of patients receiving 0 mg/day was 20%–40% during the period between month −12 and month −2, decreasing to 19.2% at month −1, and subsequently to 15.4% at the index date. Post-index date, the distribution of oral GC doses tended to revert to lower categories. During follow-up, five patients (19.2%) experienced at least one relapse. Notably, all post-switch relapses occurred exclusively in patients with a history of attacks in the year preceding the index date. Conclusions This study described the treatment patterns associated with switching from non-inebilizumab biological agents to inebilizumab, indicating that such transitions are not uncommon in Japan. The switching intervals suggest that clinicians may initiate inebilizumab treatment according to the dosing interval of the previous biological agent, while also considering the mechanism and duration of action of each agent. Our observations suggest that caution should be considered at the time of switching in patients who experienced an attack in the year preceding the switch.