Do you realize how many years it can be between such studies and when (and if) there's FDA approval to actually sell a drug/treatment? IMHO, 56+ was the exit and for those who didn't, 55+ might be the best exit point for awhile. There are three major steps of drug studies. Even at the phase III level, approval can be years away, even as the drugs are actually administered to patients in expensive trials. If it adds 2B to their bottom line, that would be several years from now and meanwhile trial expenses could hurt their bottom line.