Successful Treatment of Non-small-cell Lung Cancer with Atezolizumab Following Tubulointerstitial Nephritis Due to Pembrolizumab

We herein report a 75-year-old man with non-small-cell lung cancer who developed tubulointerstitial nephritis due to pembrolizumab administration. He was successfully treated with atezolizumab following steroid administration. He was initially diagnosed with lung adenocarcinoma (T1bN3M1b, stage IV), with a programmed cell death-ligand 1 tumor proportion score of 25-49%. Although the tumor responded well to pembrolizumab, the drug was discontinued because of the diagnosis of tubulointerstitial nephritis on a renal biopsy. Tubulointerstitial nephritis was treated with 30 mg prednisolone, the dose of which was tapered to and maintained at 5 mg. Following lung cancer progression, atezolizumab was administered, and the tumor responded again. Its efficacy has been sustained for >15 months without recurrence of tubulointerstitial nephritis.