Efficacy and Safety of Infliximab for Management of Immune-Related Adverse Events: A Retrospective Analysis

Immune-related adverse events (irAEs) are common complications of immune checkpoint inhibitor (ICI) therapy and frequently require immunosuppressive treatment. Infliximab is commonly used for steroid-refractory irAEs; however, the optimal dosing strategy remains unclear. The study objective is to evaluate the efficacy and safety of infliximab and assess the impact of dosing strategies across diverse irAEs. We retrospectively analyzed patients treated at our institution who developed irAEs requiring infliximab. Patients were grouped according to infliximab starting dose and total number of doses received. Treatment outcomes and infliximab-related adverse events were assessed. The study included 457 patients with irAEs treated with infliximab. Among 443 patients receiving 5 mg/kg infliximab, 342 received 1–2 doses and 101 received ≥ 3 doses. Patients receiving ≥ 3 doses had higher 8-week remission rates than those receiving 1–2 doses (75 versus 49%, p < 0.01) despite a longer time to response (19 versus 6 days, p = 0.01). Univariate analysis identified baseline Common Terminology Criteria for Adverse Events (CTCAE) grade, combination immunotherapy, lower gastrointestinal toxicity, and receipt of ≥ 3 doses as predictors of response. Dose escalation to 10 mg/kg was rare, and no increase in adverse events was observed. Infliximab 5 mg/kg appears to be a safe and effective treatment for diverse steroid-refractory irAEs. Receipt of ≥ 3 doses was associated with higher remission rates without increased toxicity. Prospective studies are needed to define optimal dosing strategies.