UPDATE 1-Brokers upgrade Dendreon on cancer vaccine data

April 29 (Reuters) - At least three brokerages upgraded Dendreon Corp (DNDN.O) Wednesday, a day after data on the biotech company's experimental cancer vaccine Provenge, showed improved survival in patients with advanced prostate cancer.

Shares of the company were up 118 percent at $25.78 in Wednesday morning trade on Nasdaq. They had earlier touched a lifetime high of $27.40.

Analysts called the data robust with a clean safety profile and said they expect Provenge to get approval from the U.S. Food and Drug Administration. Dendreon plans to seek U.S. approval of Provenge, known chemically as sipuleucel-T, in the fourth quarter.

"We believe the data are robust and support a strong regulatory package submission to the FDA towards year-end 2009 and a potential launch in mid-2010," Needham and Co analyst Mark Monane said in a note to clients.

Monane upgraded the stock to "buy" from "hold."

Lazard Capital Markets analyst Joel Sendek said he expects Provenge to see some off-label use in earlier-stage patients or from boosting doses, given its safety profile and mechanism of action.

Unlike traditional vaccines that prevent disease, Provenge treats it by stimulating the body's own immune system to attack cancer cells. If approved, Provenge would be the first cancer immunotherapy on the market.

Dendreon shares swung wildly on Tuesday -- at one point rising 16 percent but then sliding more than 60 percent as investors awaited the Provenge data -- prompting a brief probe and trade halt by the Nasdaq market oversight body. [ID:nN28347736] (Reporting by Esha Dey in Bangalore; Editing by Anthony Kurian)