ECOG-ACRIN activated a Symptom Science protocol (EAQ172) looking at assessing pneumonitis response to additional immunosuppression in patients with steroid-refractory pneumonitis at 28-days. This study includes radiographic and correlative biospecimen response research aims. EAQ172: Optimizing Immunosuppression for Steroid-Refractory Anti-PD-1/PD-L1 Pneumonitis.