The Economist’s article reporting on developments in gene therapy for rare diseases mentions something important:

The lessons from Glybera, the first gene therapy to be sold in Europe, still loom large. It cures a genetic condition that causes a dangerously high amount of fat to build up in the blood system. Priced at $1m, the product has only been bought once since 2012 and stands out as a commercial disaster.

Incredibly high need for the patient, but high development costs, essentially non-existent consumer base, no competition, no economies of scale, and no consumer bargaining power. Any one of those can destroy a market, but all at once? The only thing that would make it worse is if the patients can’t pay. Oh, right. They can’t. Because it costs $1m. If I’ve ever heard of a perfect government job, then this is it.

In the US, rare disease treatments will need to be covered by CMS and the associated costs spread across the entire tax base, because the free market will quite literally never be able to find a humane solution for this problem. Good luck using charity, vouchers or tax credits to cover a $1m treatment.