Objective The interleukin-6 (IL-6) inhibitor satralizumab is an established treatment for neuromyelitis optica spectrum disorder (NMOSD). Although IL-6 inhibitors are generally well-tolerated, serious infections, including sepsis, can occur. In this study, we compared the sepsis characteristics in NMOSD patients administered satralizumab (NMOSD-satralizumab) to those in rheumatoid arthritis patients administered tocilizumab (RA-tocilizumab), another IL-6 inhibitor. Methods We examined adverse event reports from the Japanese Pharmaceuticals and Medical Devices Agency regarding NMOSD-satralizumab from August 2020 to March 2022 and RA-tocilizumab from April 2008 to November 2019 (term 1) and to March 2022 (term 2). Results We identified 6 sepsis cases in NMOSD-satralizumab, of which 5 (83%) developed from urinary tract infections (UTIs). Although data were unavailable for two patients, three cases had urologic complications in addition to recognized risk factors for serious infections, such as an older age, corticosteroid use, obesity, diabetes mellitus and motor disability. Urosepsis was relatively infrequent in RA-tocilizumab (term 1: 24.2%, term 2: 20.1%). Conclusion Safe satralizumab use requires risk factor assessment to minimize the incidence of severe infections. Management of UTIs is also recommended.
Keywords: neuromyelitis optica spectrum disorder; satralizumab; sepsis; urinary tract infections.