Preclinical Data Presented on ARIAD`s Investigational mTOR Inhibitor, Deforolimus, in Lung Cancer and Other Solid Tumor Models

Data Support Use of Genetic Biomarkers to Identify Patients and Vertical Pathway
Synergy To Select Combination Regimens
DENVER & CAMBRIDGE, Mass.--(Business Wire)--
ARIAD Pharmaceuticals, Inc. (NASDAQ: ARIA) today announced the results of
preclinical studies in support of the ongoing clinical evaluation of its oral
investigational mTOR inhibitor, deforolimus, in patients with non-small cell
lung cancer and certain other solid tumors. These findings, which are being
presented by scientists from ARIAD`s partner, Merck & Co., Inc., at the annual
meeting of the American Association for Cancer Research (AACR), provide further
evidence of mTOR as a validated cancer target with potential clinical
applicability in several different tumor types.

"The single-agent activity of deforolimus observed in preclinical models
provides a compelling rationale for our recently initiated Phase 2 clinical
trial of deforolimus in patients with non-small cell lung cancer whose tumors
have a KRAS mutation. These results are particularly important considering the
limitations of available treatments for such patients," said Timothy P.
Clackson, Ph.D., senior vice president and chief scientific officer of ARIAD.
"In addition, the data on deforolimus in combination with Merck`s IGF-1R
inhibitor, MK-0646, confirm the rationale for using these two investigational
drugs together in diverse types of solid tumors. Our ongoing Phase 1 trial of
this combination represents an important opportunity for our oncology
partnership."

Deforolimus in Non-Small Cell Lung Cancer with KRAS Mutation

Deforolimus demonstrated potent single-agent, anti-tumor activity in preclinical
models of non-small cell lung cancer with a KRAS mutation.

Approximately 20 percent of non-small cell lung tumors have KRAS mutations, and
these tumors typically do not respond well to EGFR inhibitors, such as
erlotinib. In a panel of more than one hundred lung-cancer cell lines,
deforolimus showed greater inhibition of tumor growth than erlotinib in 79
percent of cell lines tested and 84 percent of KRAS mutant cell lines. Further,
deforolimus potently inhibited the growth of erlotinib-resistant, KRAS-mutant
tumors in three different mouse models.

These data lend support for the choice of patients with advanced non-small cell
lung cancer whose tumors have a KRAS mutation as the target population for study
in the ongoing randomized, double-blind, placebo-controlled Phase 2 clinical
trial of oral deforolimus.

Deforolimus and MK-0646 Combination

Deforolimus in combination with Merck`s anti-IGF-1R monoclonal antibody,
MK-0646, licensed from Pierre Fabre Medicament, led to more effective pathway
targeting and anti-tumor activity than with either investigational agent alone
in several preclinical models.

The insulin-like growth factor-1 receptor (IGF-1R) is activated in many tumor
types, leading to tumor-cell proliferation. IGF-1R functions, in part, through
activation of mTOR. In the research presented, a genetic screen identified mTOR
and IGF-1R as complimentary drug targets. Testing in panels of cell lines and
mouse models showed that combined treatment with these two investigational
agents can provide significantly enhanced anti-tumor activity. The mechanism of
this dual effect was confirmed as "vertical-pathway synergy" and blocking of
feedback signaling between IGF-1R and mTOR.

These data support the ongoing Phase 1 study of oral deforolimus combined with
MK-0646 in patients with advanced solid tumors, which is designed to evaluate
the hypothesis of vertical-pathway synergy by inhibiting two targets in the
PI3K-Akt-mTOR pathway. This multicenter study is aimed at determining the safety
profile, tolerability and recommended doses for use in subsequent trials of the
combination regimen.

About Deforolimus

ARIAD`s lead product candidate, deforolimus, is a novel rapamycin analog that
specifically and potently inhibits mTOR, a downstream activator of the PI3K/Akt
and nutrient sensing pathways. The mTOR protein acts as a "master switch" in
cancer cells. Blocking mTOR creates a starvation-like effect in cancer cells by
interfering with cell growth, division, metabolism, and angiogenesis. Multiple
Phase 1 and Phase 2 clinical trials of deforolimus in solid tumors and
hematologic cancers have been completed, or are in the process of patient
enrollment. The global Phase 3 SUCCEED trial of oral deforolimus in metastatic
soft-tissue and bone sarcomas is based on a Special Protocol Assessment agreed
upon by the U.S. Food and Drug Administration. ARIAD has a global partnership
with Merck & Co., Inc. to develop and commercialize deforolimus in patients with
cancer.

About ARIAD

ARIAD`s vision is to transform the lives of cancer patients with breakthrough
medicines. The Company`s mission is to discover, develop and commercialize
small-molecule drugs to treat cancer in patients with the greatest and most
urgent unmet medical need - aggressive cancers where current therapies are
inadequate. ARIAD`s lead product candidate, deforolimus, is an investigational
mTOR inhibitor in Phase 3 clinical development in patients with advanced
sarcomas and is being developed in collaboration with Merck & Co., Inc. ARIAD`s
second product candidate, AP24534, is an investigational multi-targeted kinase
inhibitor in Phase 1 clinical development in patients with hematological
cancers. ARIAD has an exclusive license to pioneering technology and patents
related to certain NF-κB cell-signaling activity, which may be useful in
treating certain diseases. For additional information about the Company, please
visit http://www.ariad.com.

This press release contains "forward-looking statements." Forward-looking
statements are based on management's expectations and are subject to certain
factors, risks and uncertainties that may cause actual results, outcome of
events, timing and performance to differ materially from those expressed or
implied by such statements. These risks and uncertainties include, but are not
limited to, preclinical data and early-stage clinical data that may not be
replicated in later-stage clinical studies, the costs associated with our
research, development, manufacturing and other activities, the conduct, timing
and results of pre-clinical and clinical studies of our product candidates, the
adequacy of our capital resources and the availability of additional funding,
and other factors detailed in the Company's public filings with the U.S.
Securities and Exchange Commission. The information contained in this press
release is believed to be current as of the date of original issue. The Company
does not intend to update any of the forward-looking statements after the date
of this document to conform these statements to actual results or to changes in
the Company's expectations, except as required by law.

ARIAD Pharmaceuticals, Inc.
Maria E. Cantor, 617-621-2208

Copyright Business Wire 2009