EXHIBIT 99.1
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ARIAD Reports First Quarter 2005 Results; Sarcoma Market Highlights

    CAMBRIDGE, Mass.--(BUSINESS WIRE)--May 4, 2005--ARIAD
Pharmaceuticals, Inc. (Nasdaq: ARIA) today announced financial results
for the quarter ended March 31, 2005 and provided an update on
progress towards achievement of 2005 goals.
    "We recently chose the treatment of soft-tissue and bone sarcomas
as the initial registration path for our novel mTOR inhibitor,
AP23573, which was designated a fast-track product by the U.S. Food
and Drug Administration (FDA) for this indication. We also initiated
several additional clinical trials of AP23573: Phase 2 studies in
patients with hormone-refractory prostate cancer and Phase 1b studies
combining AP23573 with two chemotherapeutic agents in patients with
various solid tumors. Finally, the Investigational New Drug (IND)
application for the oral dosage form of AP23573 became effective, and
we expect to begin enrollment in this clinical trial shortly," said
Harvey J. Berger, M.D., chairman and chief executive officer of ARIAD.
"We are clearly on track to achieve all of our key product-development
milestones for 2005 on or ahead of schedule."

    Financial Highlights

    For the quarter ended March 31, 2005, the Company reported a net
loss of $12.3 million, or $0.23 per share, as compared to $6.2
million, or $0.13 per share, for the quarter ended March 31, 2004. The
increase in net loss for the quarter is due primarily to higher R&D
expenses resulting from execution of the global development plan for
its lead cancer product candidate, AP23573. Cash used in operations
for the quarter was $10.1 million, consistent with the Company's
guidance for 2005 of $39 million to $42 million.
    The Company ended the first quarter 2005 with $63.4 million in
cash, cash equivalents, and marketable securities, compared with $75.5
million at the end of 2004.

    Sarcoma Market Highlights

    Urgent Unmet Medical Need. Fast-track designation by the FDA is
granted only when there is an urgent need for a new treatment.
Patients with soft-tissue and bone sarcomas have a serious and
life-threatening condition for which treatment options are limited or
non-existent. There are no effective therapies currently available for
advanced soft-tissue sarcomas or metastatic refractory sarcomas in
general.
    The Numbers. In the U.S. alone, public health authorities estimate
current sarcoma prevalence and incidence of new cases and deaths as
follows(1,2).
- -0-
*T

   Sarcoma Type       Prevalence    New Cases  Sarcoma Deaths
   Soft Tissue          71,343       9,420         3,490
   Bone and Joint       27,684       2,570         1,210

*T

    To put these numbers in perspective:

    --  They are exclusive of Europe, Japan, China and the rest of the
        world.

    --  The prevalence of all sarcomas is more than five times higher
        than the prevalence of chronic myelogenous leukemia (CML) -
        the initial indication for imatinib (Gleevec(R)).

    Types of Sarcoma. Sarcomas are malignant tumors associated with
one of the various connective tissues that hold the body together,
such as muscles, nerves, bones, fat, tendons, cartilage, blood vessel
or deep skin tissues. Sarcomas can develop in any part of the body.
Half of them develop in the arms or legs; the rest arise in the trunk,
head and neck area, internal organs, or the back of the abdominal
cavity. Sarcomas are generally divided into two broad classes:
soft-tissue sarcomas and bone sarcomas.
    Soft-tissue Sarcomas. Soft-tissue sarcomas are the most frequent
form of the disease. Since many patients with soft-tissue sarcoma are
not diagnosed until the disease is far advanced, the 5-year survival
rate of those patients with distant metastases is only 10% to 15%.
    Primary Bone Sarcomas. The three most common kinds of primary bone
sarcomas are: osteosarcoma (35%), chondrosarcoma (30%) and the Ewing's
family of tumors (16%). Osteosarcoma primarily affects adolescents and
young adults and is almost always a highly aggressive tumor with
either detectable or subclinical metastases.

    References.

    (1) Jemal A, et al. Cancer Statistics, 2005. CA: A Cancer Journal
for Clinicians 55(1): 10-30(2005).
    (2) Statistical Research and Applications Branch National Cancer
Institue. Website: http://seer.cancer.gov/canques/. Accessed April 19,
2005.

    Upcoming Scientific Meetings

    Clinical investigators from major cancer centers will be
presenting Phase 2 and Phase 1 data on AP23573 at the:

    --  American Society of Clinical Oncology Annual Meeting, Orlando,
        Florida, May 13-17, 2005.

    Upcoming Investor Meetings

    ARIAD management will be presenting updated overviews of the
Company's progress and plans at investor conferences - all to be
webcast - including the following:

    --  Bank of America Healthcare Conference at the Four Seasons
        Hotel in Las Vegas, Nevada, May 18, 2005

    --  Fourth Annual Needham Biotechnology Conference at the New York
        Palace Hotel in New York, New York, May 25-26, 2005

    About AP23573

    The 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 a
fast-track product by the U.S. Food and Drug Administration for the
treatment of soft tissue and bone sarcomas.

    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.

    Gleevec is a 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
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 those
costs related to the global development plan for AP23573, the adequacy
of our capital resources and the availability of additional funding,
risks and uncertainties regarding our ability to manufacture our
product candidates on a commercial scale or to supply our product
candidates to our collaborator for use in its product candidates,
risks and uncertainties regarding our and our collaborator's ability
to successfully enroll and conduct preclinical and clinical studies of
product candidates, including our product candidate to treat cancer
described in this release and our collaborator's medical device
product candidates 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 our collaborator's product candidates, risks
and uncertainties of third-party intellectual property claims relating
to our and our 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 our 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.

ARIAD PHARMACEUTICALS, INC. AND SUBSIDIARIES
CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS

In thousands, except share and                   Three Months Ended
per share data                                        March 31,
                                              -----------------------
                                                  2005        2004
                                              -----------------------
                                                     (Unaudited)

Total revenue                                $       304  $       190
                                              ----------   ----------
Operating expenses:
          Research and development                10,654        4,333
          General and administrative               2,316        2,218
                                              ----------   ----------
                  Total operating expenses        12,970        6,551
                                              ----------   ----------
Other income, net                                    320          126
                                              ----------   ----------
Net loss                                     $   (12,346) $    (6,235)
                                              ==========   ==========
Net loss per share                           $      (.23) $      (.13)
                                              ==========   ==========
Weighted average number of
   shares of common stock outstanding         52,807,513   47,540,854



CONDENSED CONSOLIDATED BALANCE SHEET INFORMATION

                                               March 31,  December 31,
In thousands                                      2005        2004
                                                -------     -------
                                               (Unaudited)
Cash, cash equivalents and marketable
 securities                                     $63,370     $75,506
Total assets                                    $76,332     $87,189
Total liabilities                               $20,852     $19,749
Stockholders' equity                            $55,480     $67,440


    CONTACT: ARIAD Pharmaceuticals, Inc.
             (Investors)
             Tom Pearson, 617-621-2345
             or
             (Media)
             Pure Communications
             Sheryl Seapy, 949-608-0841