Keytruda was a life saver for my husband with pancreatic cancer which metastasized to the adrenal glands 8 months after chemo and excision. We were thrilled that he fit the guidelines for it. Clearly the side effects were minimal as he went through it. He felt he had his life back with the treatment within 2 months the metastasis had disappeared and stayed out of site at least. He would still use it again. He was on it for 2 years which we understand is usually as long as a person is on it for. He had some itchiness during that time that was controlled with medication. At the end of the 2 years ,He had not stopped it when he began having a very rare side effect for Keytruda, an autoimmune illness. They stopped the Keytruda. The side effect was mucositis in the mouth. This has been abated with steroids and is going into remission with another medication. Although this was difficult, once the biopsy was made and diagnosis & treatment was in place he has responded well. The blessing has been he is finishing his 5th year since his PC diagnosis.