A Case of PMR-Like irAE Developing After Treatment With Ipilimumab and Nivolumab for Lung Cancer.

Immune-checkpoint inhibitors (ICIs) have become one of the main strategies for advanced cancers. ICIs are associated with many immune side effects, called immune-related adverse events (irAEs). Since irAE has various variations, it is important to carefully examine each individual case that develops irAE. We experienced a case of polymyalgia rheumatica (PMR)-like irAE after three courses of administration of Ipilimumab and Nivolumab for stage IV lung adenocarcinoma. We also confirmed that the activity of this irAE was detectable on the PET-CT scan performed to assess lung cancer progression. Given the limited reports of PMR-like irAE occurring after treatment with two immune checkpoint inhibitors, we present this case along with a review of the literature.