NEW YORK (TheStreet) -- Shares of Celldex Therapeutics  (CLDX - Get Report) soared 24.48% to $17.63 in morning trading Monday after the company announced positive results of its immunotherapy in treating a certain type of brain tumor.

The company announced its experimental, targeted immunotherapy called rindopepimut, combined with Roche's  (RHHBY) Avastin, delayed tumor growth and extended survival in patients with a specific kind of recurring brain tumor. The interim results came from a mid-stage trial, and the data was presented during a medical meeting on Friday.

Celldex organized the study for rindopepimut to be exploratory rather than for seeking regulatory approval, but the positive results led the company to say it is considering meeting with the FDA after the final data emerges in three to six months.

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More than 8.5 million shares had changed hands as of 11:01 a.m., compared to the average volume of 2,045,370.

For more on this story, read TheStreet's Adam Feuerstein's in-depth coverage here.

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