Diffuse Alveolar Hemorrhage With Avelumab Maintenance Therapy

Immune checkpoint blockade is a rapidly expanding therapeutic modality in oncology. However, its adverse effects extend beyond the cytotoxicity of conventional chemotherapy. Pneumotoxicity associated with immune checkpoint therapy presents a diagnostic conundrum that has been further complicated by the COVID-19 pandemic. We report a case of a patient with metastatic urothelial carcinoma who developed diffuse alveolar hemorrhage (DAH) following treatment with avelumab.