Interestingly, as of 03/30/2010, the price per share of CLDX needs to be around $150 for the market value of CLDX to match that of DNDN (at $4.91 bn). Hope that makes you more thrilled with a second thought at $15.
i've noticed the same thing, only that i don't think DNDN is partnered with anyone. So you'd have to adjust for that. That said CLDX might have more products than dndn if they are eventually successful.