Its not approval, its unblinding of the trial. If the late breaker is related to this, the trial must have been unblinded this morning, which raises the question of why they did not release the news to the public immediately. Messy handling.
in such cases, the FDA may inform that due to continued evidence of a proven benefit to the patient there is no further data required and approval is granted. If this happens to be the case, an approval announcement could be released as soon as the statement is drawn (formally written to Dendreon). If so, there will be deafening silence and no media person will be able to get anything until the statement is released.
Why would you say "Messy handling"??? Since there is an independant group handling the data/unblinding, DNDN does need sometime to put together the news release. So, I would think after the bell, but if there was bad news, we wouldnt be up 50%.