Here's my SWAG at chances of success:
Kevetrin: 0.15
Prurisol: 0.2
Rest of pipeline: 0.1
So overall chance of failure is 0.85*0.8*0.9 = 0.612.
Of course, the results from the different drugs will come at different times, so the situation is more complicated.
If there are early indications that kevetrin has a favorable safety and efficacy profile, the SP could jump by a factor of 3-5 by Xmas. If there are early indications of problems with kevetrin, the SP could drop by a similar factor.
It's also quite possible that kevetrin (or prurisol, or the rest of the pipeline) could have favorable phase 1 results, but will fail during later stage trials. This is why, if the phase 1 trials are favorable, and the SP jumps, I plan to sell a fraction of my holdings, such that my remaining shares are essentially free.
I've seen far too many 'can't-lose' stocks crash and burn to risk more than a smallish fraction of my portfolio on one.
A1