Exhibit 99.1

ARIAD Announces Key Promotions in Research and Development

    CAMBRIDGE, Mass.--(BUSINESS WIRE)--Sept. 30, 2003--ARIAD
Pharmaceuticals, Inc. (Nasdaq: ARIA) today announced the appointment
of three senior ARIAD executives to the leadership of its research and
development organization: Timothy Clackson, Ph.D. as Chief Scientific
Officer, John Iuliucci, Ph.D. as Chief Development Officer, and Tomi
Sawyer, Ph.D. as Senior Vice President, Drug Discovery.
    Dr. Clackson has led the discovery and development of ARIAD's
portfolio of mTOR cell-signaling inhibitors, including AP23573 and
AP23841, and its ARGENT(TM) cell-signaling regulation technology. Dr.
Iuliucci has spearheaded the Company's product development and
pharmacology activities, including filing the IND for AP23573 by its
regulatory group. Dr. Sawyer has led the discovery and development of
ARIAD's portfolio of oncogenic tyrosine kinase inhibitors, including
the Src/Abl inhibitor, AP23464.
    "I am delighted to recognize the leadership and scientific
contributions of these internationally recognized R&D executives. They
have worked seamlessly together to build ARIAD's product pipeline,
intellectual property, and drug-discovery platform and are poised to
assume even greater responsibilities as the Company realizes the
promise of its exciting product portfolio," said Harvey J. Berger,
M.D., chairman and chief executive officer of ARIAD.
    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.

    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
             or
             Kathy Lawton, 617-621-2345