8-K

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                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                    FORM 8-K

                                 CURRENT REPORT
                         PURSUANT TO SECTION 13 OR 15(D)
                                     OF THE
                         SECURITIES EXCHANGE ACT OF 1934


         Date of Report (Date of earliest event reported): May 18, 1999


                         COMMISSION FILE NUMBER: 0-21696

                           ARIAD PHARMACEUTICALS, INC.
             (Exact name of Registrant as specified in its charter)

                                    
              DELAWARE                               22-3106987
   (State or other jurisdiction of         (I.R.S. Employer Identification No.)
   incorporation or organization)


              26 LANDSDOWNE STREET, CAMBRIDGE, MASSACHUSETTS 02139
               (Address of principal executive offices)(Zip Code)

       REGISTRANT'S TELEPHONE NUMBER, INCLUDING AREA CODE: (617) 494-0400

               Former Name, Former Address and Former Fiscal Year,
                  If Changed Since Last Report: Not Applicable






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ITEM 5.  OTHER EVENTS

         On May 18, 1999, ARIAD Pharmaceuticals, Inc. (the "Company") announced
         that the exercise deadline for its Common Stock Purchase Warrants (the
         "Warrants") had been extended from 5:00 p.m. New York City time on May
         20, 1999 to 5:00 p.m. New York City time on December 30, 1999. The
         extension was effected by an amendment to the Warrant Agreement between
         the Company and the State Street Bank and Trust Company of Boston,
         Massachusetts, who acts as Warrant Agent for the Warrants. All other
         terms of the Warrants remain unchanged. The Warrants are exercisable at
         $8.40 per share and are traded on the Nasdaq Market under the symbol:
         ARIAW.


ITEM 7.  FINANCIAL STATEMENTS AND EXHIBITS.

         (a)      Financial statements of businesses acquired. Not applicable.

         (b)      Pro forma financial information. Not applicable.

         (c)      Exhibits

         Exhibit
         NO.
         ------- 

         4.1      Amendment to Warrant Agreement, dated as of May 17, 1999

         99.1     Press Release dated May 18, 1999.


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                                   Signatures

Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned hereunto duly authorized.

                                         ARIAD Pharmaceuticals, Inc.


Date:   May 18, 1999                     By: /s/ Jay R. LaMarche
                                             -----------------------------------
                                             Jay R. LaMarche
                                             Executive Vice President and
                                             Chief Financial Officer

EX-4.1

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                                                                     EXHIBIT 4.1


                                    AMENDMENT


         THIS AMENDMENT NO. 1 is made as of May 17, 1999, by and between ARIAD
Pharmaceuticals, Inc., a Delaware corporation (the "Company"), and State Street
Bank and Trust Company, a corporation organized under the banking laws of the
Commonwealth of Massachusetts (the "Warrant Agent"). All capitalized terms used
herein but not otherwise defined shall have the meanings ascribed to such terms
in that certain Warrant Agreement, dated as of May 27, 1994, by and between the
Company and the Warrant Agent (the "Warrant Agreement").

         WHEREAS, the fixed date component of the Exercise Deadline for the
Warrants will arrive less than one month from the date hereof;

         WHEREAS, the Company and the Warrant Agent desire to amend the Warrant
Agreement to extend the fixed date component of the Exercise Deadline; and

         WHEREAS, an amendment of the Warrant Agreement to extend the fixed date
component of the Exercise Deadline will not adversely affect, alter or change
the rights, privileges or immunities of the registered holders of the Warrant
Certificates;

         NOW, THEREFORE, in consideration of the mutual covenants contained
herein and other good and valuable consideration, the receipt and sufficiency of
which are hereby acknowledged, the parties agree as follows:


                  1. EXTENSION OF EXERCISE DEADLINE. The parties agree to amend
         Section 2.2 of the Warrant Agreement, which is entitled "REGISTRATION
         OF COMMON


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         STOCK AND EXERCISABILITY OF WARRANTS", by deleting the first
         sentence of Section 2.2 in its entirety and replacing such first
         sentence with the following:

         "Each Public Warrant may be exercised at any time on or after the
         Separability Date and each UPW Warrant may be exercised at any time on
         or after one year from the effective date of the Registration Statement
         (the "Effective Date") under the Securities Act of 1933, as amended
         (the "Securities Act"), but not after 5:00 P.M., New York City time, on
         the earlier of December 30, 1999, or the business day immediately
         preceding the Call Date (as defined in Section 4.11)."


                  2. RATIFICATION AND CONFIRMATION. Except as set forth above,
         the terms, conditions, agreements, representations and covenants
         contained in the Warrant Agreement are hereby ratified and confirmed in
         all respects and continue in full force and effect.


                  [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK]



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         IN WITNESS WHEREOF, the Company and the Warrant Agent have caused this
Amendment to be duly executed as of the date first above written.



COMPANY:                                    WARRANT AGENT:
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ARIAD PHARMACEUTICALS, INC.                 STATE STREET BANK AND TRUST COMPANY



By: /s/ Jay R. LaMarche                              By: /s/ Charlie Rossi
    ------------------------------                       -----------------------
Name:  Jay R. LaMarche                               Name: Charlie Rossi
Its:   Chief Financial Officer                       Its:  Vice President

EX-99.1

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                                                                    EXHIBIT 99.1
[GRAPHIC OMITTED]
                                                                    NEWS RELEASE

- --------------------------------------------------------------------------------
   
FOR IMMEDIATE RELEASE               CONTACT:          Jay R. LaMarche
                                                      Chief Financial Officer
                                                      (617) 494-0400

                                                      Jennifer LaVin
                                                      Bridge Communications
                                                      (212) 554-4158

             ARIAD ANNOUNCES EXTENSION OF THE EXPIRATION DATE OF ITS
                         COMMON STOCK PURCHASE WARRANTS

Cambridge, MA, May 18, 1999 -- ARIAD Pharmaceuticals, Inc. (Nasdaq: ARIA) today
announced that the exercise deadline for its Common Stock Purchase Warrants has
been extended from 5:00 p.m. New York City time on May 20, 1999 to 5:00 p.m. New
York City time on December 30, 1999. The extension was effected by an amendment
to the Warrant Agreement between ARIAD and the State Street Bank and Trust
Company of Boston, Massachusetts, which acts as Warrant Agent for ARIAD's Common
Stock Purchase Warrants.

All other terms of the Warrants remain unchanged. The Warrants are exercisable
at $8.40 per share and are traded on the Nasdaq Market under the symbol: ARIAW.

ARIAD Pharmaceuticals (www.ariad.com) is a leader in the discovery and
development of orally administered therapeutics based on signal transduction
technology. ARIAD is developing diverse products in multiple businesses,
including signal transduction inhibitors, gene and cell therapy (based on
ARGENT(TM)) and functional genomics. ARIAD recently announced the successful
completion of a Phase 1 human clinical trial on its small-molecule drug (AP1903)
to treat graft-versus-host-disease (GvHD) using ARGENT(TM) in patients
undergoing allogeneic bone marrow transplants.

Some of the matters discussed in this news release are forward-looking
statements that involve risks and uncertainties, including, but not limited to,
risks and uncertainties regarding the success of the Company's operations, as
well as risks and uncertainties relating to economic conditions, markets,
products, competition, intellectual property, services and prices, key
employees, future capital needs, dependence on our collaborators and other
factors discussed under the heading "Cautionary Statement Regarding
Forward-Looking Statements" in ARIAD's Annual Report on Form 10-K for the fiscal
year ended December 31, 1998 filed with the Securities Exchange Commission.



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