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By Ransdell Pierson
NEW YORK, May 31 Dendreon Corp. on Thursday said the U.S. Food and Drug Administration has informed it that positive interim or final survival data from an ongoing trial of its Provenge cancer vaccine would satisfy the agency's earlier request for more data, lifting shares 42 percent.
"We anticipate completing enrollment in the ... study this year and anticipate interim survival results in 2008," Dendreon DNDN.O said in a release. Provenge is a so-called therapeutic vaccine against prostate cancer, meaning it is meant to stimulate the immune system to fight existing tumors.
Thursday's rally in Dendreon shares is the latest in a string of dramatic share-price flip-flops for the Seattle-based drugmaker, whose stock tumbled just three weeks ago after the FDA said it would need more data before it could approve Provenge. On other occasions, the stock has staged major rallies, when prospects for Provenge appeared on the upswing.
Dendreon on May 9 said the FDA had issued an "approvable letter" for the product but wanted additional data in support of its efficacy claim, suggesting a likely delay for the vaccine that jolted investors and the stock.
The company subsequently cut 40 jobs connected with marketing of the product, or about 18 percent of its work force.
The FDA in January accepted Dendreon's marketing application for Provenge on a "fast-track" basis, based in part on suggestions it might be able to prolong survival.
An FDA advisory panel in March said Provenge appeared reasonably safe and there was "substantial evidence" of its benefits, causing shares to triple.
The stock's roller-coaster movements have been due to uncertainty created by mixed trial data. Although two Dendreon studies failed to meet their main goal of slowing progress of advanced cancer, one analysis found patients treated with Provenge lived about 4.5 months longer than those receiving placebos.
The vaccine has been studied in men with prostate cancer who had stopped responding to hormone therapy but were not having pain.
If approved, the product could boost prospects for other therapeutic vaccines, including ones being developed by GlaxoSmithKline (GSK.L) for a range of cancers.
Shares of Dendreon were up $2.82 to $9.56 in heavy morning trade on the Nasdaq.
((Reporting by Ransdell Pierson, editing by Martin Golan; Reuters Messaging: firstname.lastname@example.org; 646-223-6034; email@example.com)) Keywords: DENDREON FDA
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