Narrative review of the similarities and differences between immune checkpoint inhibitor- and antibody-drug conjugate-associated pneumonitis.

Background and Objective: The adverse events (AEs) associated with immune checkpoint inhibitors (ICIs) and antibody-drug conjugates (ADCs) are clinically significant. The early recognition and effective management of AEs are critical for improving prognosis and ensuring compliance. However, due to limitations in current AE management, the expert consensus and guidelines for the early prevention, diagnosis, and treatment of drug-associated pneumonitis remain insufficient. With the potentially increasing use of combined immunotherapy and ADCs, closer scrutiny of the overlapping and distinct AEs associated with these therapies is necessary. Focusing on checkpoint inhibitor-associated pneumonitis (CIP) and ADC-associated pneumonitis, this narrative review discusses the similarities and differences between these two conditions in terms of epidemiological characteristics, pathogenesis, clinical manifestations, and management to inform clinical practice and future research. Methods: The PubMed and China National Knowledge Infrastructure databases were searched to retrieve literature (including reviews, case reports, and clinical studies, expert consensuses, and clinical guidelines) on CIP and ADC-associated pneumonitis published in the past 7 years on September 1, 2025. Findings from multiple research articles were reviewed to generate a coherent summary of the progress in this field. Their epidemiological characteristics, pathogenesis, clinical manifestations, and management were compared to inform clinical practice. Key Content and Findings: The latest research on CIP and ADC-associated pneumonitis is summarized. The management strategies for the two conditions differ significantly: CIP is diagnosed via clinical, imaging, and pathological findings, and is primarily treated with immunosuppressants (e.g., glucocorticoids); while ADC-associated pneumonitis relies on early detection via biomarkers, and its primary therapeutic strategy is the immediate discontinuation of ADC, followed by stepwise interventions with glucocorticoids, immunoglobulins, or cytokine antagonists based on the severity of the condition to reduce lung injury. Tailored treatment plans should be formulated based on the specific features of CIP or ADC-associated pneumonitis and individual patient factors. Conclusions: CIP and ADC-associated pneumonitis exhibit both differences and shared characteristics in epidemiology, pathogenesis, clinical presentation, diagnosis, and treatment. In clinical practice, it is essential to clarify the differences between the two approaches to explore the application of precision medicine in a clinically-oriented manner, and further refine intervention and prediction methods.