Resolution of Corticosteroid Refractory Checkpoint Inhibitor–Induced Pneumonitis With Tocilizumab and Mycophenolate Mofetil Therapy

A 69-year-old woman with metastatic esophageal cancer, undergoing treatment with FOLFOX (folinic acid, fluorouracil, and oxaliplatin), pembrolizumab, and trastuzumab, developed fever and hypoxemia following her fourth treatment cycle. Clinical presentation and radiographic findings confirmed a diagnosis of immune-related pneumonitis. Her condition deteriorated despite high-dose glucocorticoid therapy, necessitating intensive care unit management. Administration of tocilizumab and mycophenolate mofetil resulted in a dramatic improvement within 48 hours, leading to extubation and eventual hospital discharge. This case underscores the critical role of intensified immunosuppressive therapy for managing steroid-refractory pneumonitis and highlights tocilizumab as a potential agent to reduce mortality in this challenging clinical scenario.