GSK’s MAGE-A3 Cancer Immunotherapeutic Phase 3 Study in Non-Small Cell Lung Cancer Misses First Co-Primary Endpoints

  GSK’s MAGE-A3 Cancer Immunotherapeutic Phase 3 Study in Non-Small Cell Lung
  Cancer Misses First Co-Primary Endpoints

      GSK to continue study until third co-primary endpoint is assessed

Business Wire

LEXINGTON, Mass. -- March 20, 2014

Agenus Inc. (Nasdaq: AGEN) today announced  that GlaxoSmithKline’s (NYSE: GSK)
MAGRIT^i study, a Phase 3 randomized, blinded, placebo-controlled MAGE-A3^ii
cancer immunotherapeutic trial in non-small cell lung cancer patients, which
contains Agenus’QS-21 Stimulon^® adjuvant, did not meet its first or second
co-primary endpoint. The study did not significantly extend the disease-free
survival (DFS)^iii period when compared to placebo in the overall MAGE-A3
positive patients or patients who did not receive chemotherapy.

GSK announced that it will continue the study until an analysis of the third
co-primary endpoint is complete. The third co-primary endpoint is based on
predefined criterion that was discussed with regulatory authorities. This
analysis is based on gene signature and designed to prospectively identify
MAGE-A3 positive patients who may benefit more from treatment. If further
analysis shows that the predefined gene signature subset data are successful,
there is the potential for regulatory filing. GSK anticipates that these data
should be available in 2015. Until then, GSK will remain blinded to all safety
and efficacy data.

The Independent Data Monitoring Committee for the MAGRIT study indicated that
a review of the safety information raised no specific concern for the
continuation of the trial.

About GSK’s MAGRIT Program

In this study, patients were given up to 13 intramuscular injections of either
the MAGE-A3 immunotherapeutic or placebo over a period of 27 months.

GSK currently remains blinded to further details of the analysis of the first
two co-primary endpoints in order to allow for the unbiased generation of a
mathematical model to assess the third co-primary endpoint^iv, which is
expected to be known in 2015. GSK is also continuing to evaluate whether a
gene signature can identify a population that would benefit from the same
investigational MAGE-A3 cancer immunotherapeutic in DERMA, another Phase 3
trial in melanoma, which reported on the first co-primary endpoint in
September 2013.

For additional information, please visit GSK’s website at www.gsk.com.

About Agenus

Agenus is a biopharmaceutical company developing a portfolio of
immuno-oncology candidates, including checkpoint modulators (CPMs), heat shock
protein vaccines and adjuvants. The company’s proprietary discovery engine
Retrocyte Display^® is designed to rapidly generate high quality therapeutic
antibody drug candidates using a high-throughput approach incorporating
full-length IgG format human antibody libraries expressed in mammalian
B-lineage cells. A portfolio of checkpoint modulator programs is advancing in
preclinical development. The company’s heat shock protein vaccines for cancer
and infectious disease are in Phase 2 studies. Agenus’ QS-21 Stimulon adjuvant
platform is extensively partnered with GlaxoSmithKline and Janssen and
includes several candidates in Phase 3 trials. Among Agenus and its partners,
23 programs are in clinical development. For more information, please visit
www.agenusbio.com, or connect with the company on Facebook, LinkedIn, Twitter
and Google+.

i A double-blind, randomised, placebo-controlled Phase III trial to assess the
efficacy of recMAGE-A3 + AS15 antigen-specific cancer immunotherapeutic as
adjuvant therapy in patients with MAGE-A3 positive NSCLC (MAGRIT,
NCT00480025).

ii MAGE-A3 cancer immunotherapeutic consists of recombinant MAGE-A3 protein
and a novel immunostimulant AS15 (a combination of QS-21 Stimulon^® adjuvant,
monophosphoryl lipid A, and CpG7909, a TLR-9 agonist, in a liposomal
formulation).

iii DFS is defined as the time from randomization to the date of first
recurrence of the disease or death, whichever comes first.

iv Access to a proportion of the data (the training set) will allow for the
unbiased generation of a mathematical model to assess the third co-primary
endpoint in the remainder of the data (the test set).

Stimulon and Retrocyte Display are registered trademarks of Agenus Inc. and
its subsidiaries.

Forward-Looking Statement

This press release contains forward-looking statements, including statements
regarding the Company’s and/or its licensees’ clinical trial activities, the
publication of data, and the potential application of technologies and 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 Annual
Report on Form 10-K filed with the Securities and Exchange Commission for the
year ended December 31, 2013. 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:

Media and Investor Contact:
Agenus Inc.
Jonae R. Barnes, 617-818-2985
Vice President
Investor Relations and Corporate Communications
jonae.barnes@agenusbio.com
 
Press spacebar to pause and continue. Press esc to stop.