https://www.fda.gov/industry/medical-products-rare-diseases-and-c...

https://www.fda.gov/industry/medical-products-rare-diseases-and-conditions/designating-orphan-product-drugs-and-biological-products

"Drugs for rare diseases go through the same rigorous scientific review process as any other drug for approval or licensing"

So, any drug can be approved after phase 2 if the results are spectacular, orphan drug designation or no orphan drug designation, rare disease or not. Covid vaccinations received accelerated approval, and Covid isn't exactly a rare disease. The FDA may very well approve ATH434-201 after the phase 2 trial is complete if the results are spectacular, but it will be because the phase 2 results are spectacular, not because of any orphan drug designation. And if the FDA aren't as easily impressed as us shareholders, then a phase 3 trial will happen.