Agenus Announces Stock Symbol to Revert Back to AGEN

Agenus Inc. (Nasdaq:AGEND), a developer of therapeutic vaccines for cancer and infectious diseases, today announced that in response to the Company's request, NASDAQ will remove the fifth character "D" from the Company's stock symbol and the Company's stock symbol will revert back to AGEN on Wednesday, October 12, 2011, at the open of the market. The fifth character "D" was appended to the Company's stock symbol to designate that the Company's common stock was trading on a post-reverse split basis.

The Company anticipates receipt of the NASDAQ compliance determination following the anticipated 10th consecutive day of closing above $1.00 per share, or after October 14, 2011.

About Agenus

Agenus Inc. is a biotechnology company working to develop treatments for cancers and infectious diseases. The company is focused on immunotherapeutic products based on strong platform technologies with multiple product candidates advancing through the clinic, including several product candidates that have advanced into late-stage clinical trials through corporate partners. For more information, please visit www.agenusbio.com.

The Agenus logo is available at http://www.globenewswire.com/newsroom/prs/?pkgid=8187

Forward-Looking Statement

This press release contains forward-looking statements, including statements regarding clinical trial activities, the publication of data, and the potential application of the Company's product candidates in the prevention and treatment of diseases. These forward-looking statements are subject to risks and uncertainties that could cause actual results to differ materially. These risks and uncertainties include, among others, the factors described under the Risk Factors section of our Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission for the period ended June 30, 2011. Agenus cautions investors not to place considerable reliance on the forward-looking statements contained in this release. These statements speak only as of the date of this document, and Agenus undertakes no obligation to update or revise the statements. All forward-looking statements are expressly qualified in their entirety by this cautionary statement. Agenus' business is subject to substantial risks and uncertainties, including those identified above. When evaluating Agenus' business and securities, investors should give careful consideration to these risks and uncertainties.

CONTACT: Jonae R. Barnes, 617-818-2985