By the way, Teva ( TEVA) and BioSante have not disclosed the exact royalty rate on Libigel sales except to say that it's mid-single digits. Bob H.'s email is more indicative of the response I've received about BioSante this week: "Wow, you are a bleep ing bleep ! Pretty clear you bleep ing some bleep , you bleep ing bleep . Go bleep yourself -- nobody likes you." I did post the uncensored and clearly NSFW version of Bob's email to my Twitter feed for those who want a laugh. @oncoslearning asks, "What's your take on Exelixis ( EXEL) and the impact of their recent stock offering?" The $65 million stock offering, priced at $5.50 per share, probably doesn't do much to enhance Exelixis' credibility with investors. Remember, the company raised money almost a year ago at $11 per share. Deal pricing is going in the wrong direction. Stepping back from the stock offering, Exelixis' experimental prostate cancer drug cabozantinib -- "cabo" for short -- suffers from an identity crisis. Existing cabo data suggest the drug is effective at reducing bone pain in late-stage prostate cancer patients, yet FDA won't allow the drug to be approved based solely on a pain-lowering benefit. Exelixis must show that cabo can prolong survival but where is the evidence the drug can do that? Further clouding cabo's future are competing drugs -- Zytiga, MDV3100, Alpharadin, OGX-011-- that have demonstrated or may demonstrate a survival benefit in prostate cancer patients well before the two phase III studies of cabo are completed. For Exelixis, cabo might be too little, too late. --Written by Adam Feuerstein in Boston. >To contact the writer of this article, click here: Adam Feuerstein. >To follow the writer on Twitter, go to http://twitter.com/adamfeuerstein. >To submit a news tip, send an email to: firstname.lastname@example.org. Follow TheStreet on Twitter and become a fan on Facebook.