Before even more people send me angry messages on here or Twitter, or leave comments without reading my article fully, please read these clarifying comments that I wrote in my original article.
Observing it in a direct clinical setting isn't completely necessary. Just something more than animal and in vitro studies. Anti-Factor Xa reduction seems like it is a very strong indicator, and it's almost logical to assume that it should be, but trial data is very limited. I don't believe there's enough data to support that conclusion just yet.
The reason I pose: "Does this reduction directly correlate to a reduction in bleeding?" is because I wanted to spark debate on this very topic.
For the purposes of learning and eventually ushering in more advancements on the topic, I think Portola has put together a fine study. I don't suggest furthering this study by using medication on patients in urgent care (outlined in my quote from the company), but in my opinion something more than animal models is needed to directly relate a reduction of Anti Factor-Xa activity to a reduction in bleeding. Currently there are only animal models supporting such inference, which by themselves are also limited.
I admit in my very first paragraph that FDA approval is almost unpredictable. I don't claim to have superior knowledge and thus we're left with educated guesses. I personally don't believe that Portola has presented enough data for even an accelerated approval, but I have been wrong before and could very well be this time as well.
Not every dissenting opinion is biased. If it were true as you say and this upcoming drug is "on its way", then PTLA share price would already reflect a positive decision. No company is completely devoid of negatives, and it's only in all of our good intentions to talk about anything and everything that could go wrong. Just as I admit I could very well be wrong on this opinion, you have to admit that you could be wrong as well. Otherwise we're all just investing blindly with no discourse.
Disclosure: I am/we are short PTLA.