Abstract
We report a case of drug-induced lung injury treated with prior atezolizumab and subsequent sotorasib. The patient was a 62-year-old woman with lung adenocarcinoma harbouring a KRAS G12C mutation that was resistant to chemotherapy, including immune checkpoint inhibitors. Cough and dyspnea appeared on day 80 after sotorasib was administered as second-line therapy, and chest computed tomography revealed ground glass opacities in all lung lobes. Bronchoalveolar lavage fluid showed an increased total cell count with lymphocyte predominance. The patient was considered to have lung injury caused by prior atezolizumab or sotorasib administration. Withdrawal of sotorasib did not improve symptoms and shadows in both lungs. We administered moderate-dose prednisolone and the lung disorder quickly resolved. Prednisolone tapering was completed in 2 months, followed by several months without relapse. Definitive identification of the responsible drug for the drug-induced lung injury proved challenging in the setting of exposure to multiple potential inciting agents. There is a need for high levels of clinical suspicion for timely evaluation and management.