The best I can see is to invest very heavily in the common methods underlying how the therapies get created - gene editing, knockout / interference etc. The better these work, the less risk there is that a drug is going to fail at clinical trials. It means, a lot more basic research as well as applied research to translate the findings.
Then we need to work on smoothing the clinical trials pathway as much as possible so that if a method is operating from proven principles it doesn't have to jump every single hurdle as if it is completely novel. Obviously, there are huge risks here if it goes wrong. But on the other hand, we can look at the cancer space and see that patients get very ready access to experimental drugs there, and overall it is enormously beneficial to overall progress. Rare disease sits somewhere in the middle - people are not (usually) dying but their life quality is so heavily compromised that there ought to be some allowance for a more accelerated access to trial drugs than if we are talking about routine medical use.