Cancers have higher mutation rates and also constantly rearrange their genome including deletions. Given that they’re looking for Novel epitopes it goes to reason these are not high copy number hence deletions can also remove them fully. It’ll be hard for me to believe that a mutagenic cancer (which is a given here since you’re looking to treat cancers with actual mutations) will not eventually gain resistance to this therapy.
Yes you are right, I should have said that re-mutation of mutations happen far less often than accumulation of additional mutations.
Novel epitopes should be high copy number - and driver mutations will be present in 80-100% of the cancer cells. It depends how many cancer cells you get in your biopsy that you sequence I guess.
It is easier for a cancer cell to mutate or remove a cell surface protein than to mutate the same mutation targeted, but you are right - that can happen and I'm sure will be a form of treatment resistance for these types of treatment in the future.
