This is a rare bit of hopeful news for the many agitated prostate cancer patients and Dendreon investors, who have beenangry at the FDA after the agency ignored a recommendation last spring from its own advisory panel to approve the vaccine.
The FDA has approved an amended trial design of a late-stage study, which should accelerate the expected timing of final results by about one year. UPDATE: Not surprisingly, the news sent Dendreon shares up more than 7 percent by the end of trading.
Interim results are still expected in the second half of 2008. However, final results are now expected in the second half of 2009 rather than 2010, according to a Dendreon statement. The FDA will still accept positive interim or final survival data from the ongoing IMPACT trial for an amended marketing application. Last May, the FDA issued an "approvable letter," and asked for more data, after Provenge failed to show that it slowed the progress of advanced prostate cancer in two key trials. The IMPACT study is a response to the FDA's request for survival data to support approval.
There was actually some good news last month, too. American Society of Clinical Oncology meeting in San Francisco, Dendreon researchers presented data demonstrating the correlation of a measure of the cumulative potency of the vaccine with overall survival. And they claim this is “the first time that an association between higher potency of an active immune therapy and increased patient survival has been reported.”
In two Phase III trials, D9901 and D9902A, researchers evaluated cumulative product release parameters of Provenge, including CD54 upregulation, which is a measure of product potency. The results showed that Provenge patients experienced improved survival if they received more cells across the three doses of Provenge or higher cumulative CD54 upregulation values.