There is very little hope, even if you do cure thier cancers.
The spike is still there, still doing t's thing, you cure the cancer, sepsis will spring up, cure that kuru will develop, it will always cause them problems, one after another, till they die.
Best approach is to draw a red line, and understand, that these people CANNOT be helped, they are already dead.
We could exhaust the entire productivity of man, and they will still die.