<PAGE>

                                                                   Exhibit 10.11
                                                                   -------------

                       G-CSF EUROPEAN LICENSE AGREEMENT


                                by and between

                              KIRIN-AMGEN, INC.,

                           a California corporation



                                      and



                                    AMGEN,

                           a California corporation












                          Dated:   December 30, 1986
<PAGE>

                               TABLE OF CONTENTS
                               -----------------
<TABLE>
<CAPTION>
                                                                         Page
                                                                         ----
<S>                                                                      <C>
RECITALS................................................................    1

I.   DEFINITIONS........................................................    2
     1.01   Incorporation by Reference..................................    2
     1.02   Territory...................................................    2
     1.03   Party.......................................................    2
     1.04   G-CSF Products..............................................    2
     1.05   Subsidiary..................................................    2
     1.06   Net Sales...................................................    3
     1.07   Sales value.................................................    3

II.  GRANT OF LICENSE...................................................    3

     2.01   Grant of License............................................    3
     2.02   Rights to Sublicense........................................    3
     2.03   License Fee.................................................    5

III. DISCLOSURE.........................................................    6

     3.01   Disclosure..................................................    6
     3.02   Confidentiality.............................................    6

IV.  ROYALTY............................................................    8

     4.01   Royalty.....................................................    8
     4.02   Sales to Subsidiaries.......................................    8
     4.03   Payment of Royalties to Sloan Kettering Cancer Center.......    8
     4.04   Records.....................................................    9
     4.05   Terms of Accounting.........................................    9
     4.06   Late Payments...............................................   10
     4.07   Payments....................................................   11
     4.08   Taxes.......................................................   11

V.   CLINICAL TRIAL EXPENSE REIMBURSEMENT, TERMINATION OF COMPANY
     FUNDING AND NO FURTHER DATA TRANSFER...............................   11

     5.01   Reimbursement of European Clinical Trial Expenses...........   11

     5.02   Termination of Company Funding..............................   11

VI.  PATENT APPLICATIONS................................................   12

     6.01   Patent Applications.........................................   12
</TABLE>

                                      -i-
<PAGE>

                          TABLE OF CONTENTS (Cont'd)
                          ------------------

<TABLE>
<CAPTION>
                                                                         Page
                                                                         ----
<S>                                                                      <C>
VII.    PATENT AND TRADE SECRET ENFORCEMENT.............................   12

        7.01 Enforcement................................................   12
        7.02 Infringements..............................................   13
        7.03 Maintenance of Action......................................   13

VIII.   TERM AND TERMINATION............................................   15

        8.01 Term.......................................................   15
        8.02 Effective Date.............................................   15
        8.03 Default....................................................   15
        8.04 Survival...................................................   16

IX.     INFRINGEMENTS...................................................   16

        9.01 Infringements..............................................   16

X.      CONSENTS AND APPROVALS..........................................   17

        10.01 Best Efforts..............................................   17

XI.     NOTICE..........................................................   17

        11.01 Notices...................................................   17

XII.    MISCELLANEOUS...................................................   18

        12.01 Entire Agreement..........................................   18
        12.02 Headings..................................................   19
        12.03 Execution in Counterparts.................................   19
        12.04 Force Majeure.............................................   19
        12.05 Applicable Law............................................   19
        12.06 Assignment on Written Consent.............................   20
        12.07 Severability..............................................   20
        12.08 No Waiver.................................................   20
        12.09 Trademarks and Tradenames.................................   20
        12.10 Indemnity.................................................   21
        12.11 Other Agreements..........................................   21
        12.12 Remedies..................................................   21
        12.13 Attorneys' Fees and Costs.................................   22
        12.14 Number and Gender.........................................   22
        12.15 Agreement to Perform Necessary Acts.......................   22
        12.16 Representations...........................................   23

SIGNATURE PAGE..........................................................   23

EXHIBIT "A" - TERRITORY OF EUROPE
</TABLE>

                                      -ii-
<PAGE>

                            AMGEN/KIRIN-AMGEN, INC.
                            -----------------------

                       G-CSF EUROPEAN LICENSE AGREEMENT
                       --------------------------------


          THIS AMGEN/KIRIN-AMGEN, INC. G-CSF EUROPEAN LICENSE AGREEMENT
("Agreement") is made and entered into and is made effective as of this 30th day
of December, 1986, by and between KIRIN-AMGEN, INC., a California corporation
("Company"), and AMGEN, a California corporation, in the process of
reincorporating in Delaware ("Amgen").


                                R E C I T A L S


          WHEREAS, effective July 1, 1986, KIRIN BREWERY CO., LTD., a Japanese
corporation ("Kirin"), and Amgen assigned all of their right, title and interest
in and to the G-CSF Technology (as defined herein) to Company,

          WHEREAS, Kirin and Amgen have each been granted a license by Company
for the development, manufacture and sale of G-CSF Products (as defined herein),
in Japan with respect to Kirin, and in the United States with respect to Amgen,
and

          WHEREAS, Company now desires to grant to Amgen an exclusive license to
further develop, manufacture, and sell G-CSF Products for the territory of
Europe (as defined herein),
<PAGE>

          NOW, THEREFORE, in consideration of the mutual covenants expressed
herein and other good and valuable consideration, the parties hereby agree as
follows:

                                   ARTICLE I

                                  DEFINITIONS
                                  -----------

          1.01   Incorporation by Reference. Unless otherwise defined herein,
                 --------------------------
capitalized terms shall have the meanings specified in that certain Company
Shareholders' Agreement dated May 11, 1984, as amended ("Shareholder
Agreement").

          1.02   Territory. "Territory" shall mean the territory of Europe as
                 ---------
more fully described on Exhibit "A" attached hereto.

          1.03   Party. "Party" shall mean Amgen or the Company or, when used in
                 -----
the plural, Amgen and the Company.

          1.04   G-CSF Products. "G-CSF Products" shall mean products with
                 --------------
respect to all indications of G-CSF Technology, unless otherwise mutually agreed
in writing between the parties.

          1.05   G-CSF Technology. "G-CSF Technology" shall mean (i) pluripotent
                 ----------------
human granulocyte colony stimulating factor which includes the gene, host vector
systems, and G-CSF producing cells (including microorganisms) used for G-CSF
expression, and all proprietary technical information, technology, know-how and
patents related to G-CSF, natural sources of G-CSF and any G-CSF materials
purified from natural sources, and (ii) the commercial production system (an
established in vivo assay system and commercially viable

                                      -2-
<PAGE>

expression system which will enable the achievement of a high level of
expression and purification to produce sufficient materials for commercial
development and marketing) for the manufacture of G-CSF Products (as defined
herein).

          1.06   Subsidiary. "Subsidiary" shall mean a corporate entity more
                 ----------
than 50% of the voting stock of which is owned or controlled, directly or
indirectly, by Amgen or the Company.

          1.07   Sales Value. "Sales Value" shall mean the gross amount billed
                 -----------
by Amgen and its subsidiaries, as the case may be, to customers with respect to
the sale or use of G-CSF Products less (a) trade and/or quantity discounts to
the extent permitted by law; (b) returns and allowances; and (c) retroactive
price reductions.


                                  ARTICLE II

                               GRANT OF LICENSE
                               ----------------

          2.01   Grant of License. For the purposes of this Agreement and
                 ----------------
subject to the reservations contained in Section 2.02 hereof, the Company hereby
grants to Amgen a sole and exclusive license to all G-CSF Technology solely for
use in the manufacture and marketing of G-CSF Products in the Territory.

          2.02   Rights to Sublicense.
                 --------------------

                 (a)   Amgen shall have no right to grant sublicenses for the
marketing of G-CSF Products in the United Kingdom, France or Germany.

                 (b)   The Company grants to Amgen the right to grant
sublicenses for the manufacturing and marketing of G-CSF

                                      -3-
<PAGE>

Products only to an Amgen subsidiary in Italy, Belgium, The Netherlands,
Luxembourg and Spain; provided, however, that Amgen shall have the right to
grant sublicenses to a third party in any of the countries set forth in the
preceding part of this sentence if local governmental laws, regulations, rules
or policies militate that Amgen contract with a local third party in such
country in order to effectively market G-CSF Products in such countries.

                 (C)   The Company grants to Amgen the right to grant
sublicenses for the marketing of G-CSF products in countries other than those
listed in Subparagraphs (a) and (b) of this Paragraph 2.02 within the limit and
the scope of the right and license granted by the Company to Amgen in Paragraph
2.01 hereof.

                 No sublicenses shall be granted under subparagraphs (b) and (c)
hereof without the prior written consent (which consent is not to be
unreasonably withheld) of the Company. Any sublicensees of Amgen shall undertake
in writing to be bound by the provisions of Section 3.02 hereof to the same
extent Amgen is bound. Amgen shall notify the Company of the identity of each
sublicensee to whom a sublicense is granted and provide the Company a true copy
of such sublicense. In the event that the license granted to Amgen hereunder is
terminated at any time in accordance with Article VIII, and the Company shall
not be in default under Section 8.03, the Company shall have the option to
terminate or to have Amgen assign to

                                      -4-
<PAGE>

the Company, retroactive to the date of such termination, any sublicenses
granted hereunder by Amgen to any Subsidiary of Amgen. Amgen shall include, in
all its sublicenses granted hereunder to any Subsidiary of Amgen, provisions for
such termination and assignment.

          2.03   License Fee. In addition to the royalty payments provided in
                 -----------
Article IV, the license fee paid to the Company by Amgen for the grant of the
license described in this Article II shall be based on and paid upon achievement
of the following milestones:

                    (a)  $1,000,000 (U.S.) -      Execution of this Agreement;

                    (b)  $500,000 (U.S.)   -      Publication of the Company's
                                                  PCT Patent Application
                                                  86/01708, but in no event
                                                  later than March 31, 1987;

                    (c)  $1,500,000 (U.S.) -      Filing Registration in any
                                                  country in the Territory;

                    (d)  $1,500,000 (U.S.) -      Approval of Registration in
                                                  any major country in the
                                                  Territory; and

                    (e)  $1,500,000 (U.S.) -      Commencement of Marketing in
                                                  any country in the Territory.

                                      -5-
<PAGE>

                                  ARTICLE III

                                  DISCLOSURE
                                  ----------

          3.01   Disclosure.
                 ----------

                    (a)  The Company shall, in accordance with the Shareholders'
Agreement, reasonably disclose and deliver to Amgen all G-CSF Technology in
sufficient detail to permit Amgen to employ such data for the purposes provided
herein.

                    (b)  Amgen shall have the right to attend and participate in
the Company's technical meetings, conduct plant visits at reasonable intervals
and receive information concerning the G-CSF Technology. Amgen shall be provided
with reasonable notice of the time and place of such meetings.

          3.02   Confidentiality.
                 ---------------

                    (a)  Any secret or confidential G-CSF Technology which is
disclosed to Amgen pursuant to this Agreement or the Shareholders' Agreement,
shall be designated as confidential information in the following manner:

                        (i)   If the disclosure is in written form, by
prominently marking or stamping each document containing such information with a
notice indicating the confidential and proprietary nature of the information;
and

                        (ii)  If the disclosure is in oral form, by orally
stating at the time of such disclosure that the information disclosed is
confidential and proprietary and by delivering to Amgen within fifteen (15) days
of the oral disclosure written notice confirming the confidential and
proprietary nature of the information.

                                      -6-
<PAGE>

                    (b)  Except to the extent expressly authorized by this
Agreement, the Shareholders' Agreement, or by another prior written consent of
the Company, for the term of this Agreement and thereafter, Amgen shall keep
completely confidential and shall not publish or otherwise disclose to others
and shall not use any secret or confidential G-CSF Technology disclosed or
provided to Amgen by the Company. For the purposes of this Agreement, G-CSF
Technology shall be deemed not secret or confidential to the extent, and only to
the extent, that it:

                        (i)   was known to Amgen at the time of its disclosure
    and not otherwise subject to an obligation of Amgen to keep such information
    confidential;

                        (ii)  was generally available to the public or was
    otherwise part of the public domain at the time of its disclosure;

                        (iii) became generally available to the public or became
    otherwise part of the public domain after its disclosure and other than
    through any act or omission of Amgen in breach of this Agreement; or

                        (iv)  became known to Amgen after its disclosure (A)
    from a source other than the Company (including from independent development
    by Amgen), (B) other than from a third party who had an obligation to the
    Company not to disclose such information to others, and (C) other than under
    an obligation of confidentiality.

                                      -7-
<PAGE>

Amgen may disclose any G-CSF Technology to the extent such disclosure or
delivery is necessary for Amgen to comply with laws or regulations, or to make,
use or sell under any license granted hereunder by the Company or to sublicense
others to do so; provided, that Amgen shall give the Company reasonable advance
notice of such proposed disclosure or delivery, shall use its best efforts to
secure confidential treatment of the G-CSF Technology to be disclosed and shall
advise the Company in writing of the manner in which that was done.

               (c)  The obligation of confidentiality imposed by this Section
3.02 shall survive termination of this Agreement for any reason whatsoever.



                                  ARTICLE IV

                                    ROYALTY
                                    -------

          4.01   Royalty. Amgen shall pay to the Company a royalty, at the
                 -------
applicable rate hereinafter specified, on G-CSF Products which are sold by
Amgen, any of its Subsidiaries or sublicensees in the Territory pursuant to this
Agreement. Such royalty rate shall be applied to the Sales Value of such G-CSF
Products. The royalty rate applicable to G-CSF Products shall be ten percent
(10%) of the Sales Value of G-CSF Products.

          4.02   Sales to Subsidiaries. No royalties shall be payable in respect
                 ---------------------
of any sale of G-CSF Products as between Amgen and any Subsidiary.

          4.03   Payment of Royalties to Sloan-Kettering Cancer Center. Pursuant
                 -----------------------------------------------------
to that certain Agreement by and between Amgen

                                      -8-
<PAGE>

and Sloan-Kettering Cancer Center ("S-K") dated February 12, 1986, certain
royalties are to be paid to S-K with respect to sales of G-CSF Products. The
parties hereto agree that Company and Amgen shall equally bear and assume
responsibility for the payments of any and all royalties due S-K for sales of G-
CSF Products in Europe pursuant to the S-K/Amgen Agreement.

          4.04   Records. Amgen shall keep full, complete and accurate records
                 -------
with regard to the sale of G-CSF Products sufficient to enable the Company to
verify the accuracy of the statements required by Section 4.05(a) hereof. The
Company shall have the right through its accredited outside auditing
representatives to make an examination and audit, during normal business hours,
not more frequently than annually, of all such records and such other records
and accounts as may under recognized accounting practices contain information
bearing upon the amount of royalty payable to it under this Agreement. Prompt
adjustment shall be made by the proper party to compensate for any errors or
omissions disclosed by such examination or audit. Neither such right to examine
and audit nor the right to receive such adjustment shall be affected by any
statement to the contrary, appearing on checks or otherwise, unless such
statement appears in a letter, signed by the party having such right and
delivered to the other party, expressly waiving such right.

          4.05   Terms of Accounting.
                 -------------------

                    (a)  Within sixty (60) days after the end of each semiannual
period ending on June 30th or December 31st,

                                      -9-
<PAGE>

commencing with the semiannual period within which is made the first sale of G-
CSF Products by Amgen, Amgen shall furnish to the Company a statement, in form
acceptable to the Company, certified by a responsible official of Amgen showing
all G-CSF Products sold during such semiannual period, the Sales Value of such
G-CSF Products and the amount of royalty payable thereon (or if no G-CSF
Products have been so sold, showing that fact).

                    (b)  Within such sixty (60) days Amgen shall, irrespective
of its own business and accounting methods, pay to the Company the royalties
payable for such semiannual period.

                    (c)  Amgen shall furnish whatever additional information the
Company may reasonable prescribe from time to time to enable the Company to
ascertain which G-CSF Products sold by Amgen or any of its Subsidiaries or
sublicensees permitted under this Agreement are subject to the payment of
royalty to the Company, and the amount of royalty payable thereon.

          4.06   Late Payments. Royalty payments provided for in this Agreement
                 -------------
shall, when overdue, be subject to a late payment charge calculated at an annual
rate of one percent (1%) over the prime rate in effect when the payment was due
which had been publicly announced by Security Pacific National Bank, Los
Angeles, California; provided, however, that if the amount of such late payment
charge exceeds the maximum permitted by law for such charge, such charge shall
be reduced to such maximum amount.

                                      -10-
<PAGE>

          4.07   Payments. Payment to the Company shall be made in United States
                 --------
dollars.

          4.08   Taxes. Amgen shall bear all taxes, however designated, imposed
                 -----
as a result of the existence or operation of this Agreement, including, but not
limited to, any tax on or measured by, any payment or receipt of payment
hereunder, any registration tax, any tax imposed with respect to the granting or
transfer of licenses or other rights or considerations hereunder, and any tax
which Amgen is required to withhold or deduct form payments to the Company,
except any such tax imposed upon the Company by any governmental entity within
or without the United States.



                                   ARTICLE V

                     CLINICAL TRIAL EXPENSE REIMBURSEMENT,

                     TERMINATION OF COMPANY FUNDING AND NO

                             FURTHER DATA TRANSFER
                             ---------------------

          5.01   Reimbursement of European Clinical Trial Expenses. Amgen agrees
                 -------------------------------------------------
to reimburse Company for all expenses related to European clinical trial
expenses within ninety (90) days after December 31st of each year.

          5.02   Termination of Company Funding. ,Company shall have no further
                 ------------------------------
responsibility for funding the research and development of G-CSF Technology with
respect to any country in Europe after Amgen receives approval of its Product
License Application for G-CSF Products in that country. Upon the

                                      -11-
<PAGE>

cessation of such Company funding, Amgen shall no longer have any obligation to
transfer any data to Company regarding that country with respect to G-CSF
Technology. Notwithstanding the foregoing, Company shall have the continuing
obligation with respect to the filing of patent applications as set forth in
Section 6.01 hereof.


                                  ARTICLE VI

                              PATENT APPLICATIONS
                              -------------------

          6.01   Patent Applications. Company shall pay the reasonable costs and
                 -------------------
expenses (including attorney's fees) incurred to file, prosecute and maintain in
force any patent applications or patents of the G-CSF Technology which Amgen
shall reasonably require the Company to file, prosecute or maintain in the
Territory; provided, that, to the extent an application or patent includes
subject matter not covering the manufacture, use and sale of G-CSF Products,
Amgen shall pay an equitable pro rata share of such expenses.



                                  ARTICLE VII

                      PATENT AND TRADE SECRET ENFORCEMENT
                      -----------------------------------

          7.01   Enforcement. Subject to Section 7.03 hereof, Amgen shall have
                 -----------
the right, but not the obligation, to bring, defend and maintain any appropriate
suit or action involving infringement of any patent or copyright,
misappropriation of any trade secret or interference with any other intellectual

                                      -12-
<PAGE>

property right relating to the G-CSF Technology that Amgen shall have obtained
pursuant to this Agreement.

         7.02  Infringements. Subject to Section 7.03 hereof, Amgen shall have
               -------------
the right, but not the obligation, to bring, defend and maintain any appropriate
suit or action involving infringement of any patent of the G-CSF Technology
covering only the making, use or sale of G-CSF Products. If Amgen finds it
necessary to join the Company in such suit or action, the Company shall execute
all papers and perform such other acts as may be reasonably required and may, at
its option, be represented by counsel of its choice. Amgen shall pay to the
Company its reasonable expenses (excluding its attorney's fees) in connection
with any such suit or action. Should Amgen lack standing to bring any such
action then Amgen may cause the Company to do so upon first undertaking to
indemnify and hold the Company harmless (to the extent permissible by law) from
all consequent liability and to promptly reimburse all reasonable expenses
(including attorney fees) stemming therefrom. Any amount recovered in any such
action or suit, whether by judgment or settlement, shall be paid to or retained
entirely by Amgen.

         7.03  Maintenance of Action. Amgen shall notify the Company of any
               ---------------------
material infringement of any patent regarding GCSF Technology covering the
making, use or sale of G-CSF Products and shall provide the Company with any
available evidence of such infringement. The Company and Amgen shall consult
with each other as to the best manner in which to

                                      -13-
<PAGE>

proceed. The Company shall have the first right, but no obligation, to bring or
defend any suit or action on any claim involving such infringement of any such
patent of the G-CSF Technology on such terms relating to reimbursement of
associated costs and expenses as shall be agreed to. If the Company finds it
necessary or desirable to join Amgen in such suit or action, Amgen shall execute
all papers and perform such other acts as may be reasonably required to do so
and may, at its option, be represented by counsel of its choice unless the
Company and Amgen otherwise agree, any amount recovered in any such action,
whether by judgment or settlement, after payment to the Company of such
reasonable costs and expenses (excluding attorney's fees), shall be paid to or
retained by Amgen. In the event the Company fails to take action with respect to
such infringement within a reasonable period, no less than six (6) months,
following receipt of such notice and evidence, Amgen shall have the right to
bring, defend and maintain any appropriate suit or action involving such
infringement. If Amgen finds it necessary to join the Company in such suit or
action, the Company shall execute all papers and perform such other acts as may
be reasonably required and may, at its option, be represented by counsel of its
choice. Amgen shall pay to the Company the reasonable expenses of the Company
(excluding attorney's fees) in connection with any such suit or action. Any
amount recovered in any such action or suit, whether by judgment or settlement,
after payment to the Company of such reasonable

                                      -14-
<PAGE>

costs and expenses (excluding attorney's fees), shall be paid to or retained
entirely by Amgen.


                                 ARTICLE VIII

                             TERM AND TERMINATION
                             --------------------

         8.01  Term. This Agreement shall remain in effect until the parties
               ----
mutually agree in writing to terminate said Agreement, or unless earlier
terminated pursuant to Section 8.03 hereof.

         8.02  Effective Date. This Agreement (including the license and rights
               --------------
granted under Sections 2.01 and 2.02 hereof) shall come into effect as of the
date hereof and shall remain in full force and effect until the earlier of (a)
the liquidation or dissolution of the Company other than in connection with a
continuation of the business of the Company in some other legal form, or (b)
termination pursuant to Section 8.03 hereof.

         8.03  Default. In the event that a Party (the "Defaulting Party") shall
               -------
(a) fail to make any payment hereunder when and as due, or otherwise default in
its obligations hereunder and fail to remedy such default within sixty (60) days
after such default shall have been called to its attention by notice from
another Party, (b) become bankrupt or insolvent, or file a petition in
bankruptcy or make a general assignment for the benefit of creditors or
otherwise acknowledge insolvency, or be adjudged bankruptcy, (c) go or be placed
in a process of complete liquidation other than in connection with a

                                      -15-
<PAGE>

continuation of the business of the Company in some other legal form, or (d)
suffer the appointment of a receiver for any substantial portion of its business
who shall not be discharged within sixty (60) days after his appointment, then,
and in any such event, any other Party, at its option, may terminate its
obligations to and the rights of the Defaulting Party under this Agreement upon
ten (10) days' written notice to the Defaulting Party, which termination shall
be effective as of the occurrence of the event giving rise to the option to
terminate.

         8.04  Survival. Notwithstanding the termination of a Party's
               --------
obligations to or the rights of the Defaulting Party under this Agreement in
accordance with the provisions of Section 8.03, Section 3.02 and Article VIII
hereof, shall survive such termination and continue in full force and effect for
an indefinite term. Upon termination of this Agreement for any reason, and
without limitation of other remedies, Amgen shall immediately return to the
Company (to the extent such return is technically feasible) all G-CSF Technology
in the possession of Amgen or its Subsidiaries, or of which Amgen shall have the
right to regain possession or, at the sole election of the Company, shall
destroy such G-CSF Technology (to the extent technically feasible).



                                  ARTICLE IX

                                 INFRINGEMENTS
                                 ------------

         9.01  Infringements. In the event that Amgen is charged with
               -------------
infringement or unauthorized use of the alleged

                                      -16-
<PAGE>

patent rights or proprietary rights of others by reason of the exploitation by
Amgen of G-CSF Technology or any component thereof, then the Company shall
indemnify and hold Amgen harmless from such claim to the full extent of any
damage recovery with respect to such claim and legal costs incurred in Amgen's
defense.



                                   ARTICLE X

                            CONSENTS AND APPROVALS
                            ----------------------

         10.01  Best Efforts. The parties hereto shall use their best efforts to
                ------------
obtain as soon as practicable any and all consents, approvals, orders or
authorizations required to be obtained from any governmental authority with
respect to the provisions hereof.



                                  ARTICLE XI

                                    NOTICE
                                    ------

         11.01  Notices. All notices, requests, demands and other communications
                -------
required or permitted to be given under this Agreement shall be in writing and
shall be mailed to the party to whom notice is to be given, by telex or
facsimile, and confirmed by first class mail, registered or certified, return
receipt requested, postage prepaid, and properly addressed as follows (in which
case such notice shall be deemed to have been duly given on the third 3rd) day
following the date of such sending):

                                      -17-
<PAGE>

"Amgen"                  Amgen
                         1900 Oak Terrace Lane
                         Thousand Oaks, CA 91320
                         U.S.A.
                         Telex No. 499-9315 (AMGEN)
                         Attn: Corporate Secretary

With a copy to:          Cooley, Godward, Castro,
                          Huddleson & Tatum
                         One Maritime Plaza, 20th Floor
                         San Francisco, CA 94111
                         U.S.A.
                         Telex No. 910-372-7370 Cooley SFO
                         Attn: Alan C. Mendelson, Esq.

"Company"                Kirin-Amgen, Inc
                         1900 Oak Terrace Lane
                         Thousand Oaks, CA 91320
                         U.S.A.
                         Telex No. 4994440 (AMGEN)
                         Attn: Corporate Secretary

With a copy to:          Pettit & Martin
                         355 South Grand Avenue
                         Thirty-Third Floor
                         Los Angeles, CA 90071
                         Telex No. 181025 PEMLAW LSA
                         Attn: Joel S. Marcus, Esq.

Any party by giving notice to the others in the manner provided above may change
such party's address for purposes of this Section 11.01.



                                  ARTICLE XII

                                 MISCELLANEOUS
                                 -------------

         12.01  Entire Agreement. This Agreement, together with the other
                ----------------
written agreements between the parties hereto which are referenced in the
Shareholders' Agreement, set forth the entire agreement of the parties with
respect to the subject matter hereof any may not be modified except by a writing
signed

                                      -18-
<PAGE>

by authorized representatives of the parties hereto. To the extent that there
may be conflicts or inconsistencies between the provisions of this Agreement and
those contained in the Shareholders' Agreement, the provisions of the
Shareholders' Agreement shall prevail and govern interpretation.

         12.02  Headings. Article and section headings in this Agreement are
                --------
included for convenience of reference only and shall not constitute a part of
this agreement for any other purpose.

         12.03  Execution in Counterparts. This Agreement may be executed in any
                -------------------------
number of counterparts and by different parties hereto in separate counterparts
each of which when so executed and delivered shall be deemed to be an original
and all of which counterparts of this Agreement taken together shall constitute
but one and the same instrument.

         12.04  Force Majeure. It is agreed that each of the parties hereto is
                -------------
excused from performing such acts as are required hereunder as may be prevented
by or whose purpose is frustrated by Force Majeure. The party so affected shall
give notice to the other party in writing promptly and thereupon shall be
excused from such of its obligations hereunder as it is unable to perform on
account of the Force Majeure throughout the duration thereof plus a period of
thirty (30) days.

         12.05  Applicable Law. This Agreement shall be governed by and
                --------------
construed in accordance with the internal laws, and not the law of conflicts, of
the State of California applicable to agreements made and to be performed in
such state.

                                      -19-
<PAGE>

         12.06 Assignment on Written Consent. This Agreement shall be binding
               -----------------------------
upon and inure to the benefit of the Company and Amgen and their respective
successors and assigns to the extent it is assignable. This Agreement may not be
assigned in whole or in part by Amgen (except to the newly formed Delaware
corporation), except with the prior written consent of the Company.

         12.07 Severability. In the event any one or more of the provisions
               ------------
contained in this Agreement shall be invalid, illegal or unenforceable in any
respect, the validity, legality and/or enforceability of the remaining
provisions contained herein shall not in any way be affected or impaired
thereby. In such event, such invalid provision or provisions shall be validly
reformed to as nearly approximate the intent of the parties as possible and if
unreformable, hall be severed and deleted from this Agreement.

         12.08 No Waiver. No failure or delay on the part of either party in
               ---------
exercising any right, power or remedy hereunder shall operate as a waiver
thereof; nor shall any single or partial exercise of any such right, power or
remedy preclude any other or further exercise thereof or the exercise of any
other right, power or remedy hereunder or the remedies provided by law.

         12.09 Trademarks and Tradenames. The Company grants no rights to Amgen
               -------------------------
in any trademarks or tradenames of the Company or of any of its respective
subsidiaries or affiliated companies.

                                      -20-
<PAGE>

         12.10  Indemnity. Amgen hereby (a) releases the Company from any
                ---------
obligation to defend indemnify or save Amgen and its agents and employees
harmless from and (b) agrees to defend, indemnify and save the Company harmless
from any and all cost, expenses (including attorneys' fees), liabilities,
damages and claims for any injury or death to persons or damage to or
destruction of property, or other loss, arising out of or in connection with any
product made, used or sold by Amgen or the use by Amgen of any G-CSF Technology
furnished pursuant to any provision hereunder, or otherwise arising out of or
related to the performance of this Agreement.

         12.11  Other Agreements. Any other provision of this Agreement
                ----------------
notwithstanding, nothing in this Agreement shall obligate the Company to
disclose to Amgen any information or to make available to the Amgen any
materials in violation of any obligation of secrecy or a limitation of use
imposed by a third party from whom such information or material shall have been
received.

         12.12  Remedies. No right, power or remedy herein conferred upon or
                --------
reserved to any party is intended to be exclusive of any other right, power or
remedy or remedies, and each and every right, power and remedy of any party
pursuant to this Agreement or now or hereafter existing at law or in equity or
by statute or otherwise shall to the extent-permitted by law be cumulative and
concurrent, and shall be in addition to every other right, power or remedy
pursuant to this Agreement, or now

                                      -21-
<PAGE>

or hereafter existing at law or in equity or by statute or otherwise and the
exercise or beginning of the exercise by any party of any one or more of such
rights, powers or remedies shall not preclude the simultaneous or later exercise
by any party of any or all such other rights, powers or remedies.

         12.13  Attorneys' Fees and Costs. In the event of any action at law or
                -------------------------
in equity between the parties hereto to enforce any of the provisions hereof,
the unsuccessful party or parties to such litigation shall pay to the successful
party or parties all costs and expenses, including reasonable attorneys' fees,
incurred therein by such successful party or parties; and if such successful
party or parties shall recover judgment in any such action or proceeding, such
costs, expenses and attorneys' fees may be included in and as part of such
judgment. The successful party shall be the party who is entitled to recover its
costs of suit, whether or not the suit proceeds to final judgment. A party not
entitled to recover its costs shall not recover attorneys' fees.

         12.14  Number and Gender. Words in the singular shall include the
                -----------------
plural, and words in a particular gender shall include either or both additional
genders, when the context in which such words are used indicates that such is
the intent.

         12.15  Agreement to Perform Necessary Acts. Each party agrees to
                -----------------------------------
perform any further acts and execute and deliver any and all further documents
and/or instruments which may be reasonably necessary to carry out the provisions
of this Agreement.

                                      -22-
<PAGE>

         12.16  Representations. Each of the parties hereto acknowledges and
                ---------------
agrees (i) that no representation or promise not expressly contained in this
Agreement has been made by any other party hereto or by any of its agents,
employees, representatives or attorneys; (ii) that this Agreement is not being
entered into on the basis of, oz in reliance on, any promise or representation,
expressed or implied, covering the subject matter hereof, other than those which
are set forth expressly in this Agreement; and (iii)that each has had the
opportunity to be represented by counsel of its own choice in this matter,
including the negotiations which preceded the execution of this Agreement.

         IN WITNESS WHEREOF, the parties have caused this Agreement to be
executed by their duly authorized representatives in the manner legally binding
on them as of the date first above written.

                                   KIRIN-AMGEN, INC., a
                                   California corporation

                                   By   /s/ George B. Rathmann
                                                 Its President
                                                     ---------
                                                         "Company"



                                   AMGEN, a California corporation, in the
                                   process of reincorporating in Delaware


                                   By  /s/ Robert D. Weist
                                                 Its Sr. Vice President
                                                     ------------------
                                                         "Amgen"

                                      -23-
<PAGE>

                        [MAP OF THE LICENSED TERRITORY]