Earlier quoted context omitted.
Your tone is misplaced. I'm an oncologist, and with no conflicts of interest I can assure you these drugs are a bona fide breakthrough.
As a lay person, its hard not to see the word "breakthrough" as essentially meaningless as its so overused. Insulin, and the polio vaccine I can see in that category... But there have been so many drugs like Avastin (which sadly I had personal experience with through my wife's cancer, which were supposed to be breakthroughs.. miracles etc... Yet, when the dust settled and more data beyond the initial company reported…
I think the word is justified in this context however because the rationale behind immunotherapy is very sound, and it seems able to cure a non-negligible proportion of patients with otherwise incurable disease.