I disagree with this statement. Where was the RO test in M/M? Our trial participation was low, plus we allowed mild patients with no symptoms that made the N number even lower. I think the final NEWS2 relevant patients would have been low 40s maybe? Did FDA care about RO then? Nope. Will they care now? Nope. FDA doesn't care about the science they want the primary endpoint stats, because science is full of theories on why things "should" work, but the results bare that out. FDA doesn't care if your the new kid, or if you have some fancy CCR5 antagonist. You can cover 110% of the CCR5 receptor but it means zilch if it doesn't keep people from dying.
Stats are the end all be all for the FDA, they care nothing for scientific theories. Look at remdesivir, they made an endpoint of lowered hospital stay and its a anti-viral drug that can't lower the viral load. So a drug that doesn't produce the science...but met at endpoint.
That's my opinion, and I'm sticking to it until I change it.