Clinical characteristics of cadonilimab-associated infusion reactions: a severity-stratified analysis of 52 cases and preliminary management framework

Objective To describe the clinical characteristics of infusion-related reactions (IRRs) associated with cadonilimab in a real-world cohort and propose preliminary management considerations based on these observations. Methods A descriptive retrospective case series was conducted, involving data collection from 52 patients who received cadonilimab and subsequently experienced infusion-related reactions at a tertiary hospital between July 2022 and December 2025. Patients were classified into a common IRR group (n=31) and a severe IRR group (n=21) based on the severity criteria outlined in CTCAE 6.0. We conducted a comparative analysis of baseline characteristics, IRR onset timing, clinical manifestations, management strategies, and outcomes between the two groups. Results The median time to IRR onset was 20 minutes post-infusion, with the highest proportion of recorded IRR cases occurring during the second treatment cycle (42.3%). Severe IRR manifested as multi-organ involvement in 61.9% of cases, predominantly affecting the respiratory and cardiovascular systems. Patients with severe IRR more frequently received corticosteroids combined with antihistamines (57.1% vs. 29.0%) and had higher rates of premedication (76.2% vs. 45.2%). Twenty-four patients (46.2%) attempted same-cycle infusion resumption; among these, 15 (62.5%) successfully completed the infusion without symptom recurrence. Among the 10 severe-group patients who attempted same-cycle infusion resumption, 6 (60.0%) experienced recurrent symptoms; among all 21 severe-group patients, the recurrence rate was 28.6% (6/21). The clinically relevant same-cycle recurrence rates were 9/24 overall (37.5%), 3/14 (21.4%) in the common group, and 6/10 (60.0%) in the severe group. Conclusion Cadonilimab is associated with early-onset infusion-related reactions frequently involving multiple organ systems. Based on our institutional experience, we propose a preliminary management framework that requires prospective validation before it can be recommended for routine clinical practice.