If the results go as you just described -- an eminently reasonable possibility -- the p value will be tiny, the safety record, as you note, immaculate, and the results unprecedentedly strong. The science is also well enough developed. There will be no reason whatsoever for the FDA to find fault. To the contrary, this result would be a Godsend to a Medicare system that is increasingly in need of a financial lifeline.
The most likely case is Accelerated Approval. Alternatively, just an approval without requiring a Phase 4.
The market cap will not stop at a $3B valuation for any length of time, partner or no partner. It will inevitably head toward $10B. Upon approval, that can double, but only because Anavex will need to share profits with a partner. Otherwise, it would be higher.
We just need the strong results. As the current market cap indicates, almost no one sees this coming.