Dendreon, in anticipation of potential competition from J&J and/or Medivation, has started clinical trials attempting to show that Provenge can be given in sequence with drugs like Zytiga or MDV3100 to further benefit patients. Deutsche Bank biotech analyst Robyn Karnauskas was quick to come to Dendreon's defense, calling the Zytiga news "more of a negative headline risk" that shouldn't hurt Provenge sales in the long run. "As per doctor checks, we believe Provenge and Zytiga will be sequenced and both will be used," said Karnauskas in an email note to clients. She has a buy rating on Dendreon. Investors Thursday were clearly not as sanguine on Dendreon's future. On Twitter, widely followed cancer-drug consultant Sally Church (@MaverickNY) tweeted, "the threat from Zytiga and MDV3100 to Provenge was a no brainer -- we've all written about that." @ahlstrac tweeted, "I could see $DNDN at $5 soon. They will continue to sell Provenge but will they ever be profitable? $500-$700M mkt cap co IMHO." --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: email@example.com. Follow TheStreet on Twitter and become a fan on Facebook.