Exhibit 99.1

ARIAD's Lead Oncology Product, AP23573, Effective in Combination with
Widely Used Anti-Cancer Agents

    CAMBRIDGE, Mass.--(BUSINESS WIRE)--March 30, 2004--ARIAD
Pharmaceuticals, Inc. (Nasdaq: ARIA) today announced results of
preclinical studies showing that its lead mTOR inhibitor, AP23573,
augments the anti-cancer activity of widely used cytotoxic and new
anti-cancer agents when given in combination. Included in the studies
are the molecularly targeted drugs, imatinib (Gleevec(TM)),
trastuzumab (Herceptin(R)) and an EGFR inhibitor, as well as the
chemotherapy drugs, docetaxel, doxorubicin, cisplatin and topotecan.
Phase 1 clinical trials of AP23573 in patients with advanced cancers
are currently underway, and phase 2 studies are expected to begin in
second quarter 2004.
    This research - being presented today at the American Association
for Cancer Research annual meeting supports the use of AP23573 in
multi-drug regimens for treating specific cancers, including breast,
ovarian and endometrial solid tumors and leukemia.
    "Optimally designing clinical trials may well be the single most
important factor in ensuring the success of a newly developed drug
candidate," said Harvey J. Berger, M.D., chairman and chief executive
officer of ARIAD. "In planning the expanded clinical program for
AP23573, we have been rigorous in generating and analyzing key
preclinical and clinical data for selecting the most appropriate
indications and drug regimens."
    The abstract by Victor M. Rivera, et al, "Anti-proliferative
activity of the mTOR inhibitor AP23573 in combination with cytotoxic
and targeted agents," is available on the AACR website
(http://www.aacr.org/2004AM/2004AM.asp).
    Gleevec is a trademark of Novartis AG. Herceptin is a registered
trademark of Genentech, Inc.
    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
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, 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
             Kathy Lawton, 617-621-2345