Document:

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                                                                   Exhibit 10.53

                             SECOND AMENDMENT TO THE
                        AMGEN RETIREMENT AND SAVINGS PLAN
               AS AMENDED AND RESTATED EFFECTIVE OCTOBER 15, 2001

         The Amgen Retirement and Savings Plan as Amended and Restated Effective
October 15, 2001, and as amended on February 27, 2001 (the "Plan") is hereby
amended to reflect certain provisions of the Economic Growth and Tax Relief
Reconciliation Act of 2001 ("EGTRRA"). This amendment is intended as good faith
compliance with the requirements of EGTRRA and is to be construed in accordance
with EGTRRA and guidance issued thereunder. This amendment shall also modify the
vesting schedule for Company Contributions, and designate Amgen USA Inc. as a
Participating Company. Except as otherwise provided, this amendment shall be
effective as of January 1, 2002. This amendment shall supersede the provisions
of the plan to the extent those provisions are inconsistent with the provisions
of this amendment.

     1.  Amgen USA Inc. shall be a Participating Company for so long as Amgen
         USA Inc. remains in existence, and Appendix A to the Plan is thereby
         amended to include Amgen USA Inc.

     2.  Article 7 of the Plan shall be amended as follows:

             a.   The following language is added to the beginning of Article 7
                  as Section 7.1 and all Sections under Article 7 are hereby
                  renumbered accordingly, and any references to any Sections
                  under Article 7 in the Plan are hereby amended to refer to the
                  Sections as renumbered hereunder:

                        7.1   100 Percent Vesting. Except for those
                              -------------------
                              Participants whose employment with a member
                              of the Affiliated Group was terminated on or
                              prior to December 31, 2001, a Participant's
                              interest in all of his or her Participant
                              Elected Contributions Account, Qualified
                              Matching Contributions Account, Qualified
                              Nonelective Contributions Account, Rollover
                              Contributions Account, Matching
                              Contributions Account and Nonelective
                              Contributions Account shall be 100% vested
                              and nonforfeitable at all times. If a
                              Participant's employment with a member of
                              the Affiliated Group was terminated on or
                              before December 31, 2001, then Sections
                              7.2-7.5 shall apply in determining the
                              vesting of those Accounts.

             b.   Section 7.2, as hereby amended, shall be re-titled "Vesting of
                                                                      ----------
                  Participant Elected Contributions Accounts."
                  ------------------------------------------

     3.  Section 4.1 shall be amended to read:

                  4.1   Participant Elected Contributions.  Each Participant
                        ---------------------------------
                        whose participation in the Plan is not suspended may
                        make Participant  Elected Contributions to the Trust
                        Fund pursuant to a Salary Deferral Agreement that
                        specifies the amount of the contribution.  Subject to
                        the limitations set forth in Section

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                  4.4 and Articles 13-16, the amount of the Participant Elected
                  Contributions shall be equal to any whole percentage of his or
                  her Compensation, as the Participant shall elect, except that
                  this whole percentage shall not exceed 30 percent of his or
                  her Compensation. Participant Elected Contributions shall be
                  made through payroll deductions from the Participant's
                  Compensation. If a Participant elects to make Participant
                  Elected Contributions, the contributions shall be deemed to be
                  employer contributions to the Plan for federal income tax
                  purposes and, to the extent permitted, for purposes of other
                  federal, state and local taxes. A Participant's election to
                  make Participant Elected Contributions shall constitute an
                  election to have the Participant's taxable salary or wages
                  from the Participating Company reduced by the amount of the
                  Participant Elected Contributions.

     4.  Section 4.6 is added to read in its entirety:

             4.6  Catch-up Contributions. All Participants who are eligible to
                  ----------------------
                  make Participant Elected Contributions under this Plan and
                  who have attained age 50 before the close of the Plan Year
                  shall be eligible to make catch-up contributions in
                  accordance with, and subject to the limitations of, Section
                  414(v) of the Code. Such catch-up contributions shall be
                  equal to any whole percentage of the Participant's
                  Compensation, except that this whole percentage shall not
                  exceed 30% of his or her Compensation, and such catch-up
                  contributions shall not be taken into account for purposes
                  of Matching Contributions under Section 5.1 of the Plan.
                  Such catch-up contributions shall not be taken into account
                  for purposes of the provisions of the Plan implementing the
                  required limitations of Sections 402(g) and 415 of the Code.
                  The Plan shall not be treated as failing to satisfy the
                  provisions of the Plan implementing the requirements of
                  Section 401(k)(3), 401(k)(11), 401(k)(12), 410(b), or 416 of
                  the Code, as applicable, by reason of the making of such
                  catch-up contributions.

     5.  Section 5.1 shall be amended to also be subject to the limitations of
         Section 4.6 of the Plan.

     6.  Section 4.4(d) shall be restated in its entirety to read:

             (d)  Section 415 "Annual Additions" Limit. As it described in
                  ------------------------------------
                  detail in Article 16, if amounts credited to a Participant's
                  Accounts during the Plan Year, other than earnings and
                  Rollover Contributions, exceed the Section 415 "Annual
                  Additions" Limit, then Participant elected Contributions may
                  be returned to the Participant.

     7.  Section 16.1 shall be restated in its entirety to read:

             16.1 Limitation on Contributions. Except to the extent permitted
                  ---------------------------
                  under Section 4.6 of the Plan and Section 414(v) of the Code,
                  if applicable, the Annual

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               Additions that may be contributed or allocated to a Participant
               for any Plan Year shall not exceed the lesser of:

                 (a)  $40,000 as adjusted for increases in the cost-of-living
                      under Section 415(d) of the Code, or

                 (b)  100% of the Participant's Section 415 Compensation for
                      such year.

               If a Participant's Annual Additions would exceed the foregoing
               limitation, then such Annual Additions shall be reduced by
               reducing the components thereof as necessary in the order in
               which they are listed in Section 16.5(a). Any amounts so reduced
               shall not be included in a Participant's Aggregate 401(k)
               Contributions or Aggregate 401(m) Contributions. The limitation
               in Section 16.1(b) shall not apply to any amount that otherwise
               is an Annual Addition under Section 415(l)(1) or 419A(d)(2) of
               the Code.

8.   Section 8.8 shall be restated in its entirety to read:

         8.8   Small Benefits: Lump Sum. Any other provision of this Article
               ------------------------
               notwithstanding, if the value of a Participant's entire Plan
               Benefit equals $5,000 or less (including a Plan Benefit of $0)
               before the first payment of the Plan Benefit is made, then the
               Plan Benefit shall be paid (or deemed paid if the Plan Benefit is
               $0) as soon as reasonably practicable after the Participant's
               termination of employment to the Participant (or to his or her
               Beneficiary in the case of the Participant's death) in a single
               lump sum in cash. For purposes of this section, the value of a
               Participant's Plan Benefit shall be determined without regard to
               that portion of the Participant's Account that is attributable to
               rollover contributions (and earnings allocable thereto) within
               the meaning of Sections 402(c), 403(a)(4), 403(b)(8),
               408(d)(3)(A)(ii), and 457(e)(16) of the Code.

9.   Section 8.9. shall be amended as follows:

       a. Section 8.9(a) shall be restated in its entirety to read:

         (a)   Definition of Eligible Retirement Plan. An Eligible Retirement
               --------------------------------------
               Plan is an individual retirement account described in Section
               408(a) of the Code, an individual retirement annuity described in
               Section 408(b) of the Code, an annuity contract described in
               Section 403(b) of the Code, an eligible plan under Section 457(b)
               of the Code which is maintained by a state, political subdivision
               of a state, or any agency or instrumentality of a state or
               political subdivision of a state and which agrees to separately
               account for amounts transferred into such plan from this Plan, or
               a qualified trust described in Section 401(a) of the Code, that
               accepts the Distributee's Eligible Rollover Distribution.
               However, in the case of an Eligible Rollover Distribution to a
               Beneficiary who is the Participant's surviving spouse, an
               Eligible Retirement Plan is an individual retirement account or

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                 individual retirement annuity. The definition of Eligible
                 Retirement Plan shall also apply in the case of a distribution
                 to a surviving spouse, or to a spouse or former spouse who is
                 the Alternate Payee under a qualified domestic relations order,
                 as defined in Section 414(p) of the Code.

     b.  Section 8.9(b) shall be restated in its entirety to read:

         (b)     Definition of Eligible Rollover Distribution. An Eligible
                 --------------------------------------------
                 Rollover Distribution is any distribution of all or any portion
                 of the balance to the credit of the Distributee, except that an
                 Eligible Rollover Distribution does not include: (1) any
                 distribution that is one of a series of substantially equal
                 periodic payments (not less frequently than annually) made for
                 the life (or life expectancy) of the Distributee or the joint
                 lives (or joint life expectancies) of the Distributee and the
                 Distributee's designated beneficiary, or for a specified period
                 of 10 years or more; (2) any distribution to the extent the
                 distribution is required under Section 401(a)(9) of the Code;
                 (3) the portion of any distribution that is not includable in
                 gross income (determined without regard to the exclusion for
                 net unrealized appreciation with respect to employer
                 securities); or (4) any amount that is distributed on account
                 of hardship shall not be an eligible rollover distribution and
                 the distributee may not elect to have any portion of such a
                 distribution paid directly to an eligible retirement plan.

10.  Section 4.5(b) shall be restated in its entirety to read:

         (b)     The Eligible Employee demonstrates to the Company's
                 satisfaction that the contribution is a qualifying rollover
                 contribution under Section 402(c)(4), 403(a)(4), 457(e)(16) or
                 408(d)(3) of the Code.

11.  Article 22 shall be amended to reflect that the top-heavy requirements of
     Section 416 of the Code and Article 22 of the Plan shall not apply in any
     year beginning after December 31, 2001, in which the Plan consists solely
     of a cash or deferred arrangement which meets the requirements of Section
     401(k)(12) of the Code and matching contributions with respect to which the
     requirements of Section 401(m)(11) of the Code are met.

12.  Section 3.5(b) shall be restated in its entirety to read:

         (b)     Does not qualify as an Eligible Employee but remains a
                 Participant.

                 In accordance with Section 10.8 and 11.4, participation is also
                 suspended for 12 months if a Participant defaults on a Plan
                 loan or 6 months if a Participant takes a Hardship Withdrawal.
                 A Participant shall not make Participant Elected Contributions
                 or receive any allocation of Company Contributions with respect
                 to a period of suspended participation, but a suspended
                 Participant's Accounts shall remain invested as a part of the
                 Trust Fund and shall continue to share in the gains, income,
                 losses and expenses of the Trust Fund.

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  13. Section 11.4(a) shall be restated in its entirety to read:

               (a)    Plan participation and all employee before- and after-tax
                      contributions to the Plan and other qualified and
                      nonqualified deferred compensation plans sponsored by
                      members of the Affiliated Group shall be suspended for a
                      period of 6 months. The consequences of suspension from
                      the Plan are described in Section 3.5.

To record this Second Amendment to the Plan as set forth herein, the Company has
caused its authorized officer to execute this document this 24th day of
                                                            ----
October, 2001.
-------

                                  AMGEN INC.

                                  By:    /s/ Brian McNamee
                                     ------------------------------------------

                                  Title: Senior Vice President Human Resources
                                         --------------------------------------

                                       5<PAGE>

                                                                   Exhibit 10.54

                             SECOND AMENDMENT TO THE
                                   AMGEN INC.
                        CHANGE OF CONTROL SEVERANCE PLAN

     This Second Amendment to the Amgen Inc. Change of Control Severance Plan is
adopted as of October 16, 2001 by the Board of Directors (the "Board") of Amgen
Inc., a Delaware corporation (the "Company").

                                    RECITALS

     WHEREAS, the Company maintains the Amgen Inc. Change of Control Severance
Plan, effective as of October 20, 1998, (hereinafter the "Plan"); and

     WHEREAS, pursuant to section 11.3 of the Plan, the Company may amend the
Plan from time to time by resolution of the Board;

     NOW THEREFORE, BE IT RESOLVED, that the Plan be amended as follows,
effective January 1, 2002:

     1. Section 1(M) shall be amended and restated in its entirety as follows:

        "(M) "Group I Participants" shall mean those senior executive-level
        staff members of the Company and of Amgen USA Inc. whom the Company has
        designated as members of the Amgen Executive Committee, as such
        committee shall be constituted immediately prior to a Change of Control.
        At or before the occurrence of a Change of Control, the Company shall
        notify the Group I Participants in writing of their status as
        Participants in the Plan."

     2. Section 1(N) shall be amended and restated in its entirety as follows:

        "(N) "Group II Participants" shall mean those management-level staff
        members of the Company and of Amgen USA Inc. at the level of Director or
        equivalent and above (i.e., those employees of the Company or of Amgen
        USA Inc. whose positions have been designated as Salary Grade 32 or
        Salary Grade EL4 and above) and who are not Group I Participants, as
        such group shall be constituted immediately prior to a Change of
        Control. At or before the occurrence of a Change of Control, the Company
        shall notify the Group II Participants in writing of their status as
        Participants in the Plan."

     3. Section 1(O) shall be amended and restated in its entirety as follows:

        "(O) "Group III Participants" shall mean those management-level staff
        members of the Company and of Amgen USA Inc. at the level of Associate
        Director or equivalent (i.e., those employees of the Company or of Amgen
        USA Inc. whose positions have been designated as Salary Grade 30 or
        Salary Grade

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         EL2 or Salary Grade EL3), as such group shall be constituted
         immediately prior to a Change of Control. At or before the occurrence
         of a Change of Control, the Company shall notify the Group III
         Participants in writing of their status as Participants in the Plan."

     I hereby certify that the foregoing Second Amendment to the Plan was duly
adopted by the Board of Directors of Amgen Inc. on October 24, 2001
                                                           --

                                    AMGEN INC.

                                    By: /s/ Brian McNamee
                                       -----------------------------------------
                                    Title: Senior Vice President Human Resources
                                           -------------------------------------

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