@jchurchill5017 I have had metastatic SCC but skin origin for 13 years. In 2020 I had mets show up in my kidney and surrounding lymph nodes. Libtayo (Cemiplimab) infusions were started and continued for over 2 years. All mets disappeared and are still gone and I have been off the drug for 2.5 years. I know skin origin differs some from mucous membrane origin SCC in its response to treatments. The main side effect I had was tiredness but it wasn't debilitating. The most irritating one was that food started to taste different so my appetite decreased. Weight loss is not helpful when battling cancer. My husband was on Keytruda for several months for bladder cancer and he had the same reaction with food tastes. He also became hypothyroid due to the drug. His tiredness did not prevent him from working.
I hope you are offered an immunotherapy and have good results as it has been easier than chemo in our experience.