I just read up on it, and saw a video, all I can say is wow, I had heard of something in this arena, this must be it. I hear great things about Rituximab from someone who just took the therapy. Can Rituximab be used for what McCain has, I don't believe so...
Rituximab is mainly used in blood cancers like leukemia and lymphoma, but sometimes also for autoimmune disorders, so no, McCain is not going to benefit from it. But it was a wonder drug when it was introduced back in the 90s. RTX itself does not kill cancer cells. Think of it as the laser of laser guided bomb or killer drone. It illuminates a molecular target called CD20 found only on B cells (which are prone to turning cancerous), and the body's own soldier immune cells (T cells) then swoop down and destroy those cells. Very neat. And unlike chemo there are few side effects.