You would think that for compounds with such potentially far-reaching effects, there would be an expedited clinical trials program with informed consent from terminal patients, or something similar.
There is an entire mechanism for this, from consenting individuals in early stage trials to accelerated approvals. If you're curious, checkout the FDA's programs (http://www.fda.gov/forconsumers/byaudience/forpatientadvocat...). This isn't everything, but it represents the interest of most players in getting these medications to patients as quickly as possible.