"...what do you think about the valuation at this level?..."
It all depends on where you stand wrt the future of HSP90 inhibition. EXEL has such an inhibitor in XL-888, in which early research has displayed the potential to overcome BRAF inhibitor resistance in melanoma, and MMM has apparently placed so low a priority on that news that he hasn't even bothered to share it with his shareholders. BTW - Doesn't that news potentially constitute a material event?
I suspect the promising SNTA compound, ganetespib, is the driving motivation for Bruce Kovner's recent buying spree. The drug has shown a viable OS signal, and is thought to overcome ALK inhibitor resistance in NSCLC. Makes me wonder if the same is true of XL-888. Recent trials reporting in combination with Crizotinib have indicated a possible synergy as well, and a June 2013 publication in the NEJM seems to indicate Crizotinib may displace SOC chemo in advanced ALK-driven NSCLC. The ideal situation for G would be to ride right along with Crizo into that late-stage indication.
Does ganetespib also inhibit BRAF inhibitor resistance in melanoma, as does XL-888? Maybe...
Ganetespib is reporting a P2 melanoma trial later this year, the reults of which might be compelling, and wouldn't surprise me to find that a combo dosing trial is being planned with Zelboraf.
So - potentially - SNTA has a drug that can overcome both Crizotinib and Zelboraf treatment resistance in two advanced indications....along with one of the best AE profiles amongst existing HSP90 inhibitors.
What's that worth? JMHO - I can't produce a figure, but I think it may be worth a lot...