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Ahead of the Bell: Agenus shares tumble

The Associated Press

Shares of Agenus tumbled more than 13 percent Thursday before markets opened and after the biopharmaceutical released more ineffective study results from its collaboration with GlaxoSmithKline.

The company said a potential lung cancer treatment that included Agenus' SQ-21 Stimulon vaccine adjuvant did not significantly extend the disease-free survival period when compared with patients taking a placebo or fake drug.

The Agenus product is extracted from the bark of an evergreen tree and is being studied as a component in a variety of cancer treatments. GlaxoSmithKline PLC is studying an immune therapy that targets MAGE-A3, an antigen found in cancers including melanoma, non-small cell lung cancer, head and neck cancer, and bladder cancer.

Glaxo plans to continue studying the possible treatment to determine if patients with a particular genetic signature would benefit from it. Results from that analysis are expected next year.

Glaxo had announced in September that the treatment did not lead to greater disease-free survival in melanoma patients when compared to a placebo in a mid-stage study.

Shares of Agenus Inc., based in Lexington, Mass., fell 55 cents to $3.75 more than an hour before markets opened. U.S.-traded shares of GlaxoSmithKline dropped 2 percent, or $1.12, to $53.59.