EXHIBIT 99.1



ARIAD Research Highlights Beneficial Profile of Its Promising
           Product to Treat Cancer That Has Spread to Bone

    CAMBRIDGE, Mass.--(BUSINESS WIRE)--July 14, 2003--

             Lead Story in American Association for Cancer
                        Research Press Release

    ARIAD Pharmaceuticals, Inc. (Nasdaq: ARIA) announced, for the
first time on Saturday at the American Association for Cancer Research
press briefing on the efficacy of novel cancer treatments, results of
pre-clinical studies demonstrating the potential therapeutic benefits
of its product candidate to treat cancer that has spread to bone.
    AP23841 combines, in a single small-molecule drug, effective
blockade of both tumor growth and bone destruction - the two processes
that need to be controlled to treat the grave clinical consequences of
bone metastases.
    Of the more than 5000 abstracts that were submitted for
presentation to the 94th annual meeting of the AACR, three were
featured in its press release entitled "New generation of treatments
show promise for cancer patients: Studies show combined therapies, new
targets effective in fighting disease." The lead story in the AACR
release was ARIAD's product candidate to treat cancer in bone.
    Even though none of the available therapies for bone metastases
directly affects both tumor growth and bone destruction, sales of
zoledronic acid (Zometa(R)), the leading bisphosphonate used for this
indication, are estimated to reach approximately $1 billion in 2003.
    "The development of a novel therapy for bone metastases that acts
directly and potently on both tumor growth and bone destruction should
be highly desirable from a clinical and mechanistic standpoint and
should have potential added benefit over existing drugs used to treat
this disease," said Harvey J. Berger, M.D., chairman and chief
executive officer of ARIAD.
    Approximately 750,000 cancer patients worldwide will die this year
with bone metastases. Some of the most common solid tumors - breast,
prostate, lung and kidney cancer - commonly spread to bone, resulting
in severe bone pain and pathological fractures due to increased bone
fragility.
    AP23841 is similar to ARIAD's lead cancer product, AP23573. Both
product candidates inhibit the activity of a protein known as mTOR,
which results in the starvation of cancer cells. However, AP23841 is
designed to selectively concentrate in bone, which should deliver a
more potent therapeutic effect to cancer cells that have migrated to
bone. AP23841 also blocks the activity of bone cells responsible for
bone destruction. Stopping bone destruction impedes the release of
growth factors that attract cancer cells to bone and stimulate their
proliferation in bone.
    Saturday's press release issued by the AACR is available at the
AACR web site (http://www.aacr.org/1132ab.asp), as is the abstract by
Metcalf, C., et al, "A novel, bone-targeted mTOR inhibitor that
decreases both tumor proliferation and bone breakdown for the
treatment of cancer," (http://www.aacr.org/2003AM/2003AM.asp).
    ARIAD is engaged in the discovery and development of breakthrough
medicines that regulate cell signaling with small molecules. The
Company is developing a comprehensive approach to the treatment of
cancer and is primarily focused on a series of product candidates for
targeted oncology indications. ARIAD also has an exclusive license to
pioneering technology and patents related to the discovery,
development and use of drugs that regulate NF-(kappa)B cell-signaling
activity, which has been implicated in many major diseases.
    Additional information about ARIAD can be found on the web at
http://www.ariad.com.

    Zometa(R) is a registered trademark of Novartis AG.

    Some of the matters discussed herein are "forward-looking
statements" within the meaning of the Private Securities Litigation
Reform Act of 1995. Such statements are identified by the use of words
such as "anticipate," "estimate," "expect," "project," "intend,"
"plan," "believe," and other words and terms of similar meaning in
connection with any discussion of future operating or financial
performance. Such statements are based on management's current
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 forward-looking statements. These risks include, but are not
limited to, risks and uncertainties regarding the Company's ability to
conduct preclinical and clinical studies of its product candidates and
the results of such studies, regulatory oversight, intellectual
property claims, the timing, scope, cost and outcome of legal
proceedings, future capital needs, key employees, dependence on the
Company's collaborators and manufacturers, markets, economic
conditions, products, services, prices, reimbursement rates,
competition and other risks detailed in the Company's public filings
with the Securities and Exchange Commission, including ARIAD's Annual
Report on Form 10-K for the fiscal year ended December 31, 2002. The
information contained in this document 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.

    CONTACT: ARIAD Pharmaceuticals, Inc.
             Tom Pearson, 610/407-9260
             Kathy Lawton, 617/621-2345



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