TBH, I believe that is a huge root cause problem with our health care system. We need to stop pretending that money is infinite, and measure the cost against the benefit (in this case, little or none) when deciding whether Medicare/insurance companies should pay for a treatment.
Perhaps this shouldn't be the responsibility of the FDA, but SOMEWHERE there should exist a process that says, "OK, this drug increases lifespan on average by 1 week, but costs $10,000 a month in treatment, sorry we're not going to cover it."