Successful use of Remcyte®-based continuous hemodiafiltration in a case of refractory CRS and ICANS complicated by tumor lysis syndrome-associated AKI.

Cytokine release syndrome and immune effector cell-associated neurotoxicity syndrome are severe complications associated with T cell–redirected immunotherapies, including bispecific antibodies. These conditions are typically managed with corticosteroids and interleukin-6 receptor antagonists such as tocilizumab. However, some patients remain unresponsive to these standard treatments. We report the case of a 73-year-old woman with relapsed high-grade B-cell lymphoma treated with epcoritamab who developed persistent fever and neurological impairment following drug administration. Despite repeated use of tocilizumab and corticosteroids, her symptoms progressed, and she was admitted to the intensive care unit. Laboratory testing revealed markedly elevated interleukin-6 levels (23,000 pg/mL), and she subsequently developed acute kidney injury due to tumor lysis syndrome. Continuous blood purification therapy using Remcyte®, a novel hemodiafilter with high cytokine adsorption capacity and favorable platelet compatibility, was initiated. Within 48 h, her consciousness level improved, serum interleukin-6 decreased significantly, and blood purification was discontinued without complications. This case suggests that Remcyte® may be beneficial in cases of cytokine-mediated syndromes unresponsive to standard therapies, particularly in patients with concurrent kidney dysfunction. Further accumulation of cases is required to clarify its therapeutic indications, optimal timing of use, and clinical utility in patients without renal involvement.