UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                  SCHEDULE 13D
                    Under the Securities Exchange Act of 1934

                              IMMUNEX CORPORATION
                         ------------------------------
                                (Name of Issuer)

                          Common Stock, $.01 par value
                         ------------------------------
                         (Title of Class of Securities)

                                   45252810 2
                                  ------------
                                 (CUSIP Number)

      Steven M. Odre, Esq.                              with a copy to:
      Senior Vice President,                            Charles K. Ruck, Esq.
      General Counsel and Secretary                     Latham & Watkins
      Amgen Inc.                                        650 Town Center Drive
      One Amgen Center Drive                            Suite 2000
      Thousand Oaks, CA 91320-1799                      Costa Mesa, CA 92626
      (805) 447-1000                                    (714) 540-1235


                  (Name, Address and Telephone Number of Person
                Authorized to Receive Notices and Communications)

                               December 16, 2001
                            -------------------------
             (Date of Event which Requires Filing of this Statement)

If the filing person has previously filed a statement on Schedule 13G to report
the acquisition which is the subject of this Schedule 13D, and is filing this
statement because of Rule 13d-1(e), Rule 13d-1(f) or Rule 13d-1(g), check the
following box [_]

Note: Schedules filed in paper format shall include a signed original and five
copies of the schedule, including all exhibits. See Rule 13d-7(b) for other
parties to whom copies are to be sent.

*The remainder of this cover page shall be filled out for a reporting person's
initial filing on this form with respect to the subject class of securities, and
for any subsequent amendment containing information which would alter
disclosures provided in a prior cover page.

The information required on the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the Securities Exchange Act of
1934 ("Act") or otherwise subject to the liabilities of that section of the Act
but shall be subject to all other provisions of the Act (however, see the
Notes).



                                  SCHEDULE 13D

CUSIP No. 45252810 2

1.       NAMES OF REPORTING PERSON
         I.R.S. IDENTIFICATION NO. OF ABOVE PERSON

         Amgen Inc.
         I.R.S. Employer Identification No. 95-3540776

2.       CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP

                                                                        (a)  [_]
                                                                        (b)  [_]

3.       SEC USE ONLY


4.       SOURCE OF FUNDS

                  OO

5.       CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT TO
         ITEM 2(d) or 2(e)                                                   [_]

6.       CITIZENSHIP OR PLACE OF ORGANIZATION

                  Delaware

NUMBER OF SHARES BENEFICIALLY OWNED BY EACH
REPORTING PERSON WITH:

7.       SOLE VOTING POWER:                          223,378,088 (1)

8.       SHARED VOTING POWER:                        None

9.       SOLE DISPOSITIVE POWER:                     None

10.      SHARED DISPOSITIVE POWER:                   None

11.      AGGREGATE AMOUNT BENEFICIALLY
         OWNED BY REPORTING PERSON:                  223,378,088 (2)

12.      CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES
         CERTAIN SHARES                                                      [_]

13.      PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (11):  41.0% (3)

14.      TYPE OF REPORTING PERSON:                            CO


                                       2



1. Pursuant to an Agreement and Plan of Merger dated as of December 16, 2001
   (the "Merger Agreement"), among Amgen Inc., a Delaware corporation ("Amgen"),
   AMS Acquisition Inc., a Washington corporation and wholly-owned subsidiary
   of Amgen ("Merger Sub"), and Immunex Corporation, a Washington corporation
   ("Immunex"), and subject to the conditions set forth therein (including
   approval by stockholders of Amgen and shareholders of Immunex and the
   expiration or termination of the applicable waiting period under the Hart-
   Scott-Rodino Antitrust Improvements Act of 1976), Merger Sub will merge with
   and into Immunex and Immunex will become a wholly-owned subsidiary of Amgen
   (such events constituting the "Merger"). 223,378,088 shares of Immunex common
   stock (the "Shares") are subject to a Shareholder Voting Agreement (the
   "Voting Agreement") entered into by Amgen and certain shareholders of Immunex
   (See Schedule B attached hereto) (the "Shareholders"). Pursuant to the Voting
   Agreement, the Shareholders have agreed to vote (or cause to be voted) their
   shares (x) in favor of the approval of the terms of the Merger Agreement, the
   Merger and the other transactions contemplated by the Merger Agreement (and
   any actions required in furtherance thereof), (y) against any action,
   proposal transaction or agreement that would result in a breach in any
   respect of any covenant, representation or warranty or any other obligation
   or agreement of Immunex contained in the Merger Agreement or of any of the
   Shareholders contained in the Voting Agreement, and (z) except with the
   written consent of Amgen, against the following actions or proposals (other
   than the transactions contemplated by the Merger Agreement): (i) any
   Acquisition Proposal (as defined in the Merger Agreement) by a third party;
   and (ii) (A) any change in the persons who constitute the board of directors
   of Immunex that is not approved in advance by at least a majority of the
   persons who were directors of Immunex as of the date of the Voting Agreement
   (or their successors who were so approved); (B) any material change in the
   present capitalization of Immunex or any amendment of Immunex's articles of
   incorporation or bylaws; (C) any other material change in Immunex's corporate
   structure or business; or (D) any other action or proposal involving Immunex
   or any of its subsidiaries that is intended, or could reasonably be expected,
   to prevent, impede, interfere with, delay, postpone or adversely affect the
   transactions contemplated by the Merger Agreement. The Shareholders may vote
   the Shares on all other matters. As part of the Voting Agreement, the
   Shareholders granted an irrevocable proxy to Amgen with respect to the
   voting of the Shares for the matters covered by the Voting Agreement.

2. Amgen expressly disclaims beneficial ownership of any of the shares of
   Immunex common stock covered by the Voting Agreement.

3. Based on the number of shares of Immunex common stock outstanding as of
   December 1, 2001 (as represented by Immunex in the Merger Agreement
   discussed in Item 4 below), the number of shares of Immunex common stock
   indicated represents approximately 41.0% of the outstanding shares of
   Immunex common stock.

                                       3



Item 1. Security and Issuer.

          This statement on Schedule 13D (this "Statement") relates to the
     common stock of Immunex Corporation, a Washington corporation (sometimes
     referred to herein as "Issuer" or "Immunex"). The principal executive
     offices of Immunex are located at 51 University Street, Seattle, WA 98101.

Item 2. Identity and Background.

          (a)-(c), (f) The name of the corporation filing this Statement is
     Amgen Inc., a Delaware corporation ("Amgen"). The address of Amgen's
     principal business is One Amgen Center Drive, Thousand Oaks, CA 91320.
     Amgen is a global biotechnology company that discovers, develops,
     manufactures and markets human therapeutics based on advances in cellular
     and molecular biology. The name, citizenship, business address and present
     principal occupation of each executive officer and director of Amgen is
     listed on Schedule A attached hereto.

          (d) Neither Amgen nor, to Amgen's knowledge, any person named on
     Schedule A attached hereto is required to disclose legal proceedings
     pursuant to Item 2(d).

          (e) Neither Amgen nor, to Amgen's knowledge, any person named on
     Schedule A attached hereto is required to disclose legal proceedings
     pursuant to Item 2(e).

Item 3. Source and Amount of Funds or Other Consideration.

          As an inducement for Amgen to enter into the Merger Agreement
     described in Item 4 and in consideration thereof, certain shareholders of
     Immunex listed on Schedule B attached hereto (the "Shareholders") entered
     into a Shareholder Voting Agreement dated as of December 16, 2001, a copy
     of which is attached as Exhibit 2 (the "Voting Agreement"). Amgen did not
     pay additional consideration to the Shareholders in connection with the
     execution and delivery of the Voting Agreement.

Item 4. Purpose of Transaction.

          (a)-(b) Pursuant to an Agreement and Plan of Merger dated as of
     December 16, 2001 (the "Merger Agreement"), among Amgen, AMS Acquisition
     Inc., a Washington corporation and wholly-owned subsidiary of Amgen
     ("Merger Sub"), and Immunex, and subject to the conditions set forth
     therein (including approval by stockholders of Amgen and shareholders of
     Immunex and the expiration or termination of the applicable waiting period
     under the Hart-Scott-Rodino Antitrust Improvements Act of 1976), Merger Sub
     will merge with and into Immunex and Immunex will become a wholly-owned
     subsidiary of Amgen (such events constituting the "Merger"). Once the
     Merger is consummated, Merger Sub will cease to exist as a corporation and
     all of the business, assets, liabilities and obligations of Merger Sub will
     be merged into Immunex with Immunex remaining as the surviving corporation
     (the "Surviving Corporation").

          As a result of the Merger, each outstanding share of Immunex common
     stock, other than (i) shares owned by Merger Sub, Amgen or any wholly-owned
     subsidiary of Amgen, and (ii) dissenting shares, will be converted into the
     right to receive (a) .440 (the "Exchange Ratio") of a share of Amgen common
     stock (the "Common Stock Consideration") and (b) $4.50 in cash (the "Cash
     Consideration," and together with the Common Stock Consideration, the
     "Merger Consideration"). All such shares of Immunex common stock will no
     longer be outstanding and will automatically be canceled and retired and
     cease to exist, and each certificate previously

                                       4




     representing any such shares shall thereafter represent the right to
     receive the Merger Consideration payable in respect of such shares of
     Immunex common stock.

          The Shareholders have, by executing the Voting Agreement, agreed to
     vote the 223,378,088 shares of Immunex common stock (the "Shares")
     beneficially owned by them as described below. Pursuant to the Voting
     Agreement, the Shareholders have agreed, at every Immunex shareholders
     meeting and on every action or approval by written consent in lieu of such
     a meeting, to vote (or cause to be voted) their shares (x) in favor of the
     approval of the terms of the Merger Agreement, the Merger and the other
     transactions contemplated by the Merger Agreement (and any actions required
     in furtherance thereof), (y) against any action, proposal, transaction or
     agreement that would result in a breach in any respect of any covenant,
     representation or warranty or any other obligation or agreement of Immunex
     contained in the Merger Agreement or of any Shareholder contained in the
     Voting Agreement, and (z) except with the written consent of Amgen, against
     the following actions or proposals (other than the transactions
     contemplated by the Merger Agreement): (i) any Acquisition Proposal (as
     defined in the Merger Agreement) by a third party; and (ii) (A) any change
     in the persons who constitute the board of directors of Immunex that is not
     approved in advance by at least a majority of the persons who were
     directors of Immunex as of the date of the Voting Agreement (or their
     successors who were so approved); (B) any material change in the present
     capitalization of Immunex or any amendment of Immunex's articles of
     incorporation or bylaws; (C) any other material change in Immunex's
     corporate structure or business; or (D) any other action or proposal
     involving Immunex or any of its subsidiaries that is intended, or could
     reasonably be expected, to prevent, impede, interfere with, delay, postpone
     or adversely affect the transactions contemplated by the Merger Agreement.
     The Shareholders may vote the Shares on all other matters. The Voting
     Agreement terminates upon the earliest to occur of (i) the mutual consent
     of Amgen and American Home Products Corporation, (ii) the effective time of
     the Merger and (iii) the date of termination of the Merger Agreement. See
     Section 6.1 of the Voting Agreement, items (iv) and (v), for additional
     termination events. As part of the Voting Agreement, the Shareholders
     granted an irrevocable proxy to Amgen with respect to the voting of the
     Shares for the matters covered by the Voting Agreement.

          The purpose of the transactions under the Voting Agreement is to
     enable Amgen and Immunex to consummate the transactions contemplated under
     the Merger Agreement.

          (c) Not applicable.

          (d) Upon the consummation of the Merger, the directors of Merger Sub
     immediately prior to the effective time of the Merger will be the directors
     of the Surviving Corporation , until their respective successors are
     duly elected or appointed and qualified. Upon consummation of the Merger,
     the officers of Merger Sub immediately prior to the effective time of the
     Merger will be the initial officers of the Surviving Corporation, until
     their respective successors are duly appointed.

          (e) Other than as a result of the Merger described in Item 4(a) above,
     not applicable.

          (f) Not applicable.

          (g) At the effective time of the Merger, the articles of incorporation
     of Immunex shall be amended in their entirety to read as the articles of
     incorporation of Merger Sub (except that the name of Immunex will remain
     Immunex Corporation), and such articles of incorporation will be the
     articles of incorporation of the Surviving Corporation until thereafter
     changed or amended in accordance with applicable law. At the effective time
     of the Merger, the Bylaws of Merger Sub,

                                       5




     as in effect immediately prior to the effective time of the Merger, shall
     be the Bylaws of the Surviving Corporation, until thereafter changed or
     amended as provided therein or by applicable law.

          (h)-(i) If the Merger is consummated as planned, the Immunex common
     stock will be deregistered under the Securities Act of 1933, as amended,
     and delisted from the Nasdaq National Market.

          (j) Other than described above, Amgen currently has no plan or
     proposals which relate to, or may result in, any of the matters listed in
     Items 4(a)-(j) of Schedule 13D (although Amgen reserves the right to
     develop such plans).

          References to, and descriptions of, the Merger, the Merger Agreement
     and the Voting Agreement as set forth herein are qualified in their
     entirety by reference to the copies of the Merger Agreement and the Voting
     Agreement, respectively, included as Exhibits 1 and 2, respectively, to
     this Statement, and such agreements are incorporated herein in their
     entirety where such references and descriptions appear.

Item 5. Interest in Securities of the Issuer.

          (a)-(b) As a result of the Voting Agreement, Amgen may be deemed to
     be the beneficial owner of 223,378,088 shares of Immunex common stock. Such
     Immunex common stock constitutes approximately 41.0% of the issued and
     outstanding shares of Immunex common stock based on the number of shares of
     Immunex common stock outstanding as of December 1, 2001 (as represented by
     Immunex in the Merger Agreement discussed in Item 4 above). Amgen may be
     deemed to have the sole power to vote the Shares with respect to those
     matters described above. However, Amgen (i) is not entitled to any other
     rights as a shareholder of Immunex as to the Shares and (ii) disclaims any
     beneficial ownership of the shares of Immunex common stock which are
     covered by the Voting Agreement.

          To the knowledge of Amgen, no person listed on Schedule A hereto has
     an equity or other ownership interest in Immunex.

          (c) As described in Items 3 and 4 of this Statement, Amgen entered
     into the Voting Agreement and the Merger Agreement within the last 60 days.

          (d) To the knowledge of Amgen, no person, other than the Shareholders
     as set forth on Schedule B, has the right to receive or the power to direct
     the receipt of dividends from, or the proceeds from the sale of, the
     securities of Immunex deemed to be beneficially owned by Amgen.

          (e) Not applicable.

Item 6. Contracts, Arrangements, Understanding or Relationships With Respect to
Securities of the Issuer.

          Other than the Merger Agreement and the Voting Agreement, to the
     knowledge of Amgen, there are no contracts, arrangements, understandings or
     relationships among the persons named in Item 2 and Schedule A and between
     such persons and any other person with respect to any securities of
     Immunex, including, but not limited to, transfer or voting of any of the
     securities, finder's fees, joint ventures, loan or option arrangement, puts
     or calls, guarantees of profits, division of profits or loss, or the giving
     or withholding of proxies.

                                       6




Item 7. Material to be Filed as Exhibits.

          The following documents are filed as exhibits:

          1. Agreement and Plan of Merger, dated December 16, 2001, by and among
     Amgen, Merger Sub and Immunex (filed as an exhibit to the Form 8-K Current
     Report dated December 16, 2001 on December 17, 2001 and incorporated herein
     by reference).

          2. Shareholder Voting Agreement, dated December 16, 2001, by and among
     Amgen and certain shareholders of Immunex as listed on Schedule B hereto
     (filed as an exhibit to the Form 8-K Current Report dated December 16, 2001
     on December 17, 2001 and incorporated herein by reference).

                                       7



                                   SIGNATURES

     After reasonable inquiry and to the best knowledge and belief of the
undersigned, the undersigned certifies that the information set forth in this
statement is true, complete and correct.

Date:  December 21, 2001

                                    AMGEN INC.

                                    By:     /s/ Kevin W. Sharer
                                       --------------------------------------
                                        Name:   Kevin W. Sharer
                                        Title:  Chairman of the Board,
                                                Chief Executive Officer and
                                                President

                                       8



                                   SCHEDULE A

                 DIRECTORS AND EXECUTIVE OFFICERS OF AMGEN INC.

     The name, citizenship, business address, and present principal occupation
or employment of each of the directors and executive officers of Amgen Inc. are
set forth below.

- --------------------------------------------------------------------------------------------------- Name* Principal Occupation Business Address - --------------------------------------------------------------------------------------------------- Executive Officers - ------------------ - --------------------------------------------------------------------------------------------------- Kevin W. Sharer Chairman of the Board, Chief Amgen Inc. Executive Officer and President of One Amgen Center Drive Amgen Thousand Oaks, CA 91320-1799 - --------------------------------------------------------------------------------------------------- Richard D. Nanula Executive Vice President, Amgen Inc. Finance, Strategy and Communications, One Amgen Center Drive and Chief Financial Thousand Oaks, CA 91320-1799 Officer of Amgen - --------------------------------------------------------------------------------------------------- Brian M. McNamee Senior Vice President, Human Amgen Inc. Resources of Amgen One Amgen Center Drive Thousand Oaks, CA 91320-1799 - --------------------------------------------------------------------------------------------------- Dennis M. Fenton Executive Vice President of Amgen Inc. Amgen One Amgen Center Drive Thousand Oaks, CA 91320-1799 - --------------------------------------------------------------------------------------------------- Steven M. Odre Senior Vice President, General Amgen Inc. Counsel and Secretary of Amgen One Amgen Center Drive Thousand Oaks, CA 91320-1799 - --------------------------------------------------------------------------------------------------- George J. Morrow Executive Vice President, Worldwide Amgen Inc. Sales and Marketing of Amgen One Amgen Center Drive Thousand Oaks, CA 91320-1799 - --------------------------------------------------------------------------------------------------- George Morstyn Senior Vice President, Development, Amgen Inc. and Chief Medical Officer of Amgen One Amgen Center Drive Thousand Oaks, CA 91320-1799 - --------------------------------------------------------------------------------------------------- Roger M. Perlmutter Executive Vice President, Research Amgen Inc. and Development of Amgen One Amgen Center Drive Thousand Oaks, CA 91320-1799 - --------------------------------------------------------------------------------------------------- Fabrizio Bonanni Senior Vice President, Quality and Amgen Inc. Compliance of Amgen One Amgen Center Drive Thousand Oaks, CA 91320-1799 - --------------------------------------------------------------------------------------------------- Directors - --------- - --------------------------------------------------------------------------------------------------- David Baltimore President, California Institute of Technology California Institute of Technology Office of the President, 204-31 1200 E. California Blvd. Pasadena, California 91125 - --------------------------------------------------------------------------------------------------- William K. Bowes, Jr. General Partner, U.S. Venture U.S. Venture Partners Partners 2180 Sand Hill Road, Suite 300 Menlo Park, California 94025 - --------------------------------------------------------------------------------------------------- Jerry D. Choate (Retired) Chairman of the Board and 33971 Selva Road Chief Executive Officer Allstate Suite 130 Insurance Company Dana Point, California 92629 - ---------------------------------------------------------------------------------------------------
9
- --------------------------------------------------------------------------------------------------- Name* Principal Occupation Business Address - --------------------------------------------------------------------------------------------------- Frederick W. Gluck Consultant McKinsey & Company, Inc. McKinsey & Company, 400 South Hope Street, Suite 700 Inc. Los Angeles, California 90071 - --------------------------------------------------------------------------------------------------- Franklin P. Johnson, Jr. General Partner Asset Management Partners Asset Management Partners 2275 East Bayshore Road Suite 150 Palo Alto, California 94303 - --------------------------------------------------------------------------------------------------- Steven Lazarus Managing General Partner ARCH Venture Partners, L.P. ARCH Venture Partners, L.P. 8725 W. Higgins Road Suite 290 Chicago, Illinois 60631 - --------------------------------------------------------------------------------------------------- Gilbert S. Omenn Executive Vice President for Medical University of Michigan Affairs at the University of 1301 Catherine Drive Michigan, Chief Executive Officer of Room M7324 the University of Ann Arbor, Michigan 48109-0626 Michigan Health System and Professor of Internal Medicine, Human Genetics and Public Health - --------------------------------------------------------------------------------------------------- Judith C. Pelham President and Chief Executive Officer Trinity Health Trinity Health 27870 Cabnot Drive Novi, Michigan 48377-2920 - --------------------------------------------------------------------------------------------------- J. Paul Reason President and Chief Operating Officer Metro Machine Corporation Metro Machine Corporation 200 Ligon Street Norfolk, Virginia 23523 - --------------------------------------------------------------------------------------------------- Donald B. Rice President and Chief Executive Officer Agensys, Inc. Agensys, Inc. 1545 17th Street Santa Monica, California 90404 - --------------------------------------------------------------------------------------------------- Kevin W. Sharer Chairman of the Board, President and Amgen Inc. Chief Executive Officer One Amgen Center Drive Amgen Inc. Thousand Oaks, CA 91320-1799 - ---------------------------------------------------------------------------------------------------
- -------------- *Each person listed is a citizen of the United States. 10 SCHEDULE B Shareholders Party to a Voting Agreement with Amgen Inc. Shareholder Party to Voting Agreement Shares Beneficially Owned - ------------------------------------- ------------------------- American Home Products Corporation 223,378,088 MDP Holdings, Inc. 180,153,032 Lederle Parenterals, Inc. 43,225,056 11 INDEX OF EXHIBITS 1. Agreement and Plan of Merger, dated December 16, 2001, by and among Amgen, Merger Sub and Immunex (filed as an exhibit to the Form 8-K Current Report dated December 16, 2001 on December 17, 2001 and incorporated herein by reference). 2. Shareholder Voting Agreement, dated December 16, 2001, by and among Amgen and certain shareholders of Immunex as listed on Schedule B hereto (filed as an exhibit to the Form 8-K Current Report dated December 16, 2001 on December 17, 2001 and incorporated herein by reference). 12