Antibody-drug conjugates (ADCs) are a potent class of antineoplastic drugs that deliver cytotoxic agents via targeting with monoclonal antibodies
however, ADCs are associated with high rates of lung toxicities, limiting the therapeutic potential in many patients. We report a case of a patient with metastatic non-small cell lung cancer taking the ADC telisotuzumab vedotin (Teliso V) plus osimtertinib who developed ADC-induced pneumonitis despite clinical benefit. This patient was able to tolerate treatment for a prolonged period on a novel steroid regimen, using steroids when pneumonitis was asymptomatic but radiologically evident and as a daily suppressant. This treatment strategy may have implications in the broader management of ADC-interstitial lung disease/pneumonitis and underscores its potential mechanisms.