NEW YORK (TheStreet) -- Shares of Celldex Therapeutics  (CLDX - Get Report) surged 13.83% to $21.32 in early afternoon trading Thursday on higher-than-average volume.

The stock soared 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.

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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.

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

More than 5.4 million shares had changed hands as of 12:02 p.m., compared to the daily average volume of 2,563,690.

CLDX Chart CLDX data by YCharts

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