Exhibit 99.1

               ARIAD Receives Orphan Drug Designations for AP23573
             in the Treatment of Both Soft-Tissue and Bone Sarcomas


    CAMBRIDGE, Mass.--(BUSINESS WIRE)--Aug. 18, 2005--ARIAD
Pharmaceuticals, Inc. (Nasdaq: ARIA) today announced that AP23573, its
novel mTOR inhibitor, has been designated an orphan drug by the United
States Food and Drug Administration (FDA) for the treatment of both
soft-tissue and bone sarcomas.
    "In the absence of any effective treatments for advanced
soft-tissue sarcomas or refractory bone sarcomas that have spread, the
orphan drug designations for AP23573 provided by the FDA should help
us address this unmet medical need more effectively," said Harvey J.
Berger, M.D., chairman and chief executive officer of ARIAD. "We are
working with key regulatory agencies to advance AP23573 toward its
initial registration trial and subsequent regulatory submissions for
marketing authorization in these devastating cancers."
    Orphan drug designation, which is intended to facilitate drug
development, provides substantial potential benefits to the sponsor,
including funding for certain clinical studies, study-design
assistance, waiver of Prescription Drug User Fee Act (PDUFA) fees, tax
credits and up to seven years of market exclusivity for the product
upon regulatory approval.

    About AP23573

    ARIAD's small-molecule drug, AP23573, starves cancer cells and
shrinks tumors by inhibiting the critical cell-signaling protein,
mTOR, which regulates the response of tumor cells to nutrients and
growth factors, and controls tumor blood supply and angiogenesis
through effects on Vascular Endothelial Growth Factor (VEGF) in tumor
and endothelial cells. AP23573 also blocks the proliferation and
migration of vascular smooth muscle cells, the primary cause of
narrowing and reblockage of injured arteries, and is an analog of
sirolimus, another mTOR inhibitor that has been approved for use in
drug-eluting stents. AP23573 is currently in Phase 1 and 2 clinical
trials in patients with solid tumors and hematologic cancers. AP23573
has been designated both as a fast-track product and an orphan drug by
the U.S. Food and Drug Administration for the treatment of soft-tissue
and bone sarcomas.

    About Sarcoma

    Sarcomas are cancers of the connective tissue, including bones,
muscles, fat, cartilage, and joints and do not discriminate by age,
gender or race. Sarcomas can arise anywhere in the body and are
divided into two main groups - bone tumors and soft tissue sarcomas.
They are further sub-classified based on the type of cell or tissue
from which the tumor developed. There are approximately 12,000 new
cases of sarcoma diagnosed each year in the United States and
approximately 100,000 sarcoma patients overall in the United States.
More information about sarcomas is available at
http://www.curesarcoma.org.

    About ARIAD

    ARIAD is engaged in the discovery and development of breakthrough
medicines to treat disease 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. Medinol Ltd. also is developing stents and other medical
devices that deliver ARIAD's lead cancer product candidate to prevent
reblockage at sites of vascular injury following stent-assisted
angioplasty. ARIAD 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, including statements concerning the
potential benefits of orphan drug designation for AP23573, 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 timing and
actual research and development expenses and other costs associated
with the preclinical and clinical development and manufacture of our
product candidates, including the timing and costs related to the
global development plan for AP23573 described in this release, the
adequacy of our capital resources and the availability of additional
funding, risks and uncertainties regarding our or our collaborator's
ability to manufacture our product candidates on a commercial scale or
to supply our product candidates to collaborators, risks and
uncertainties regarding our ability to successfully enroll and conduct
preclinical and clinical studies of product candidates, including our
product candidate to treat various cancers described in this release
and our collaborator's medical device product candidate to treat
vascular disease, risks and uncertainties that clinical trial results
at any phase of development may be adverse or may not be predictive of
future results or lead to regulatory approval of any of our or any
collaborator's product candidates, risks and uncertainties of
third-party intellectual property claims relating to our and any
collaborator's product candidates, and risks and uncertainties
relating to regulatory oversight, the timing, scope, cost and outcome
of legal proceedings, including litigation concerning our NF-(kappa)B
patent portfolio, future capital needs, key employees, dependence on
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, as
amended, for the fiscal year ended December 31, 2004. 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: For ARIAD Pharmaceuticals, Inc.
             Ed Fitzgerald (Investors), 617-621-2345
             or
             Pure Communications
             Sheryl Seapy (Media), 949-608-0841