I can't answer extensively across all countries. The problem with rare diseases—and some of them will fall into the catastrophic disease category as well because of the cost—is that there is not a lot of scientific evidence that can be generated to help make the kinds of decisions that CDR has, because if a disease is very rare, there's going to be a small patient base for it, and so to do a trial to collect enough data to make meaningful conclusions is next to impossible. Add to that the fact that rare or orphan drugs, as they're called, will be much more expensive because typically they cost more to produce and they're produced for a smaller market. So all of that complicates the process.
Ultimately, one has to decide for such classes of drugs whether or not one is prepared to accept different levels of evidence. This is an argument that methodologists have. In the U.K., in NICE, they've tried to tackle this. They've even gone to look at what they call ultra-orphan diseases, which are even rarer. I mean, there are numbers in terms of prevalence. In fact, on the citizens jury that I talked about, one of the meetings I attended was when they were trying to decide how differently they would handle ultra-orphan drugs. The reality is that you can't have the same expectations for data or evidence. It just isn't possible.
In Canada, we've had similar discussions with drugs like Fabrazyme. I'm not exactly sure where CDR has ruled on any of those. As far as I know, both rare and catastrophic drugs are being discussed somewhat differently in terms of the amount of data needed to make these decisions.