Re: Analysts are not impressed . They should be
Ernie, I agree with your line of thoughts. And, I would not think Kcentra would do better against X and E than against Warfarin. That'd make little sense. I have looked at the small sample study you refer to. It is not clear what criteria they used for 'effective hemostasis.' There was another 'pooled retrospective study' done that gives you something like 350 sample points. That concludes with ~69% hemostatic effectiveness at 12 hours. That's where I wonder how much of that is X and E wearing off (begins to wear off at 24 hours).
I mean, even if 77% of patients had higher than 75 ng/mL at baseline as you quote, during the course of 12 hours, I would imagine the concentration would go lower and lower. So, I can imagine a scenario where Kcentra begins to have an impact at say 6 hours in, and by 12 hours, it achieves 'effective hemostasis.' This can cloud the final outcome.
Primary outcome of Andexxa phase 4 is the following: Proportion of patients with good or excellent hemostatic efficacy as rated by an independent adjudication committee [ Time Frame: 12 hours ]
Secondary Outcome Measures :
Change from baseline in anti-fXa activity [ Time Frame: 1-3 hours ]
I am encouraged by the secondary outcome measure. I'm certain Andexxa will beat Kcentra on that. Also, I am curious to the change of wording on the "Time Frame: 12 hours" as opposed to Annexxa-4 which said "Hemostatic effectiveness at 12 hours." I am hoping this can capture how fast hemostasis is achieved. I mean, does it not matter whether the drug stops bleeding right away or lets it bleed for another 12 hours?
Anyway, one can always come up with doubts and uncertainty. The study result won't be known for 4 years, so in the meanwhile, the real world outcomes and results will probably pile up and let us know how things are going...