Exhibit 99.1
       ARIAD Appoints Michael Kishbauch, Senior Pharmaceutical Executive,
                           to Its Board of Directors


    CAMBRIDGE, Mass.--(BUSINESS WIRE)--Sept. 23, 2004--ARIAD
Pharmaceuticals, Inc. (Nasdaq: ARIA) today announced the appointment
of Michael D. Kishbauch to its Board of Directors. Mr. Kishbauch is
president and chief executive officer of Achillion Pharmaceuticals,
Inc., a biopharmaceutical company developing drugs for serious
infections associated with drug-resistant viruses or bacteria.
    Previously, he was a founder, president and chief executive
officer of OraPharma, Inc., a commercial-stage biopharmaceutical
company developing, marketing and selling oral health care and
specialty pharmaceutical products, which was acquired in 2003 by
Johnson & Johnson, Inc. After the acquisition, he joined J&J as
president of the OraPharma division. He also held senior management
positions at Medimmune, Inc., including president and chief operating
officer, and at Ciba-Geigy Corporation, including vice president,
product planning and promotion. Mr. Kishbauch received an M.B.A. from
the Wharton School of the University of Pennsylvania and a B.A. from
Wesleyan University.
    "I am very pleased to have Mike Kishbauch join our Board of
Directors," said Harvey J. Berger, M.D., chairman and chief executive
officer of ARIAD. "Mr. Kishbauch, an ARIAD director in 2002-2003, is
an extraordinarily talented and experienced executive who has spent
his career launching and commercializing pharmaceutical products.
Since those are the challenges that we will face in the coming years,
we are fortunate that Mr. Kishbauch is returning to our Board."

    ARIAD is engaged in the discovery and development of breakthrough
medicines to treat cancer by regulating cell signaling with small
molecules. The Company is developing a comprehensive approach to
patients with cancer that addresses the greatest medical need -
aggressive and advanced-stage cancers for which current treatments are
inadequate. ARIAD also has an exclusive license to pioneering
technology and patents related to certain NF-(kappa)B treatment
methods, and the discovery and development of drugs to regulate
NF-(kappa)B cell-signaling activity, which may be useful in treating
certain 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
accurately estimate the actual research and development expenses and
other costs associated with the preclinical and clinical development
of our product candidates, the adequacy of our capital resources and
the availability of additional funding, risks and uncertainties
regarding the Company's ability to successfully conduct preclinical
and clinical studies of its product candidates, risks and
uncertainties that clinical trial results at any phase of development
may be adverse or may not be predictive of future result or lead to
regulatory approval of any of the Company's product candidates, and
risks and uncertainties relating to 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, 2003. 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
             Kelly Lindenboom, 617-621-2345