short csl, page-39

And of course, if the Phase 3 trial is successful, there's no reason why CSL112 won't be as effective in the prevention of ischaemic strokes as it is for MIs, since the mechanism for both is pretty much the same. In the US alone, every year more than 600k people have an IS, with a fatality rate of around 30%. Of those who survive, about 25% have a further stroke within five years, so CSL112 could be a real game changer, and not just for the share price.

A further point is that although the final results of the Phase 3 trial won't be in for some time, there should be plenty of useful data available well before then. If the data is seriously positive, and since the safety of CSL112 is pretty well established, it's entirely possible that the trial will have to be called off for ethical reasons (as you can't ethically continue to give 50% of the participants a placebo, if you know that the other 50% are getting a genuine and measurable benefit). In this situation the authorities could fast track approval, and allow CSL to get the drug to market a lot more quickly than planned.

In any event, my strong sense is that there's something pretty serious behind this big and rapid run up in the CSL share price, about which we're only in a position to speculate.