The real reason the drugs are priced so high is that people/insurers pay it. I wouldn't even call it a free market, since the patent protection is involved. Essentially it is extortion. Eventually we might get a situation where drug companies raise costs for patented drugs, not only cancer ones, slowly to the breaking point where even less people can afford insurance anymore. Why wouldn't they? The insurers are very disinclined to refuse life saving treatments to their patients.
With biologicals the cost of actually producing the drugs can be high. The only way to bring that down is to drive forward the necessary technology.