RE:...AZD103 Ongoing....Hopefulhomerun.
A Phasell Pivotal trial is designed to be Statistically Powered for Efficacy as well as Safety and Tolerability.
Should Statistical Significance (Stat Sig) be demonstrated the Sponsor can then submit a regulatory filing for Marketing Approval after the Phasell. All Phasell's that file for approval require a second larger Phaselll Trial. This is also a Pivotal trial.
The Drug can actually be Approved and on the Market before the Phaselll is even complete..........but the Efficacy and Safety Data have to be Stat Sig as well. If not the FDA can pull the drug off the market as fast as it approved it.
Heres an example of a recent Phasell Pivotal Trial development. NOTE: There are only 180 enrolled.....
https://www.news-medical.net/news/20091211/Phase-2-pivotal-trial-of-AC220-initiated-by-Ambit-Biosciences.aspx
There are a variety of provisions in the FDA Handbook for these sort of scenarios.
Although Transition and Elan didn't push this fact by any means they really didn't push the fact that they may advance Phaselll before Phasell was finished. Ambit clearly is pushing this Phasell Pivotal. Because AZD103 is Fast Tracked the Primary EndPoints do not have to be finalized with the Trial Design Protocol and can change or be juggled as circumstances warrant. They aren't written in stone.
This is accomplished by having the FDA intimately involved in the whole Trial. There is growing positive opinion that a Phasell Alzheimers Trial could even be deemed as being Pivotal with strong Surrogate Endpoints for Disease Modification and that then Stat Sig Efficacy would have to be proven up in a larger Phaselll. Usually the larger the Trial the easier to reach Stat Sig.