I did try 4 different types (combinations) of Chemo, prior to the keytruda. To early to tell on keytruda. Last scan was inconclusive. Will work on another 5 rounds. Side effects are not pleasant. Not very common but I am having server joint pain. Especially in my shoulders. I will keep you posted. I hope the chemo will help get some control over this for you. I have just entered year 4 of this battle. I really struggle with stopping treatment. Whenever I have been in between treatments (usually no more than a week) I have always felt great.