"At what price, you will see ELN as attractive?"
At this point, ELN is probably an excellent daytrading stock but any long-term positions have to be considered dangerous because the pps could go anywhere at any time. The real problem here is the potential Tysabri saga rather than the Alzheimer's pipeline...
If Tysabri survives because it is very much needed in spite of the lethal but rare side-effects, then ELN could go back over $20 in a flash. If Tysabri does not survive on account of mounting evidence of lethal side-effects beyond what we already know, then I would not be surprised to see ELN going as low as $1.25, which is where I bought it years ago and then sold it early at about $20...
At any rate, for now the hedgie shorts have sunk their teeth into ELN with nearly $12 Billion in sheer profit! So I would expect more downside ahead. It is too bad because my Aug $22.5 calls are expiring worthless unless a takeover miracle occurs in the next two weeks...LOL...(or maybe Crying Out Loud is a better term in this case)...