Objective Immune checkpoint inhibitors are now a standard of care for the management of many metastatic cancers, including non-small-cell lung cancer. Pembrolizumab, a selective anti–PD-1 monoclonal antibody, augments the host antitumoural response. This hyperactivation of the immune system has side effects, the so-called immunerelated adverse effects. The objective of this case report was to review and point out a new pattern of immune checkpoint inhibitor–associated pneumonitis.Case Description A 69-year-old woman with stage iv non-small-cell lung cancer receiving pembrolizumab presented for increased dyspnea. Pembrolizumab-related obstructive bronchiolitis was diagnosed based on a new severe obstructive disorder, without bronchodilator reversibility, and mosaic attenuation on angiography, without other identifiable causes.Summary To our knowledge, this is the first description of a case of pembrolizumab-induced obstructive bronchiolitis. Various patterns of immune checkpoint inhibitor–associated lung disease have been described, and bronchiolitis should be included in the differential diagnosis.
High mortality and poor treatment efficacy of immune checkpoint inhibitors in patients with severe grade checkpoint inhibitor pneumonitis in non‐small cell lung cancer