Exhibit 10.41

[NOTE: CERTAIN PORTIONS OF THIS DOCUMENT HAVE BEEN MARKED TO INDICATE THAT
CONFIDENTIAL TREATMENT HAS BEEN REQUESTED FOR SUCH PORTIONS BY IMCLONE SYSTEMS
INCORPORATED. THESE PORTIONS HAVE BEEN MARKED WITH AN ASTERISK ENCLOSED IN
BRACKETS (I.E., [*]). THE CONFIDENTIAL PORTIONS HAVE BEEN OMITTED AND FILED
SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION]

AMENDMENT NO. 2 TO DEVELOPMENT, PROMOTION,
DISTRIBUTION AND SUPPLY AGREEMENT

        This AMENDMENT NO. 2 dated as of July 27, 2007 (this "Amendment No. 2"),
is entered into by and among E.R. SQUIBB & SONS, LLC, a limited liability
company organized and existing under the laws of the State of Delaware, having
offices located at Route 206 and Province Line Road, Princeton, New Jersey 08543
("ERS"), BRISTOL-MYERS SQUIBB COMPANY, a corporation organized and existing
under the laws of the State of Delaware, having offices located at Route 206 and
Province Line Road, Princeton, New Jersey 08543 ("BMS") and IMCLONE SYSTEMS
INCORPORATED, a corporation organized under the laws of the State of Delaware,
having offices located at 180 Varick Street, New York, New York 10014 (the
"Company").

        WHEREAS ERS, BMS and the Company (collectively, the "Parties") are
parties to the Development, Promotion, Distribution and Supply Agreement among
ERS, BMS and the Company dated as of September 19, 2001, as amended by Amendment
No. 1 dated as of March 5, 2002 ("Amendment No. 1"), by and among the Parties
(the agreement as so amended, the "Agreement"), pursuant to which the Parties
have agreed to collaborate on the development and commercialization of Products
in the Territory;

        WHEREAS simultaneously with the execution of this Amendment No. 2, and
as a condition to the effectiveness of this Amendment No. 2, the Parties are
entering into a Letter of Intent Regarding the Japan Co-Commercialization
Agreements (as defined below) and the Side Letter (as defined below), and
executing the Release and Waiver (as defined below);

        NOW THEREFORE, in consideration of the mutual agreements herein
contained and other good and valuable consideration, the sufficiency and receipt
of which are hereby acknowledged, and subject to the conditions set forth
herein, the Parties hereby agree to amend the Agreement as follows:

        Definitions.    Capitalized terms used but not defined in this Amendment
No. 2 shall have the meanings set forth in the Agreement. References in the
Agreement to "this Agreement" shall be deemed to refer to the Agreement as
amended by this Amendment No. 2. Notwithstanding the foregoing, the date of the
Agreement, as amended hereby, shall in all instances remain September 19, 2001,
and references to "the date hereof", "the date of this Agreement" and "the
Effective Date" in the Agreement shall continue to refer to September 19, 2001.

Confidential Treatment Requested

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        SECTION 1.    Amendments to Section 1 and Exhibits.

        (a)   Sections 1.78 and 1.95 of the Agreement are hereby deleted in
their entirety.

        (b)   Sections 1.19 and 1.20 of the Agreement are hereby deleted in
their entirety and replaced with the following:

"1.19 "Clinical Budget" shall mean (i) the budget for Development Costs for each
Approved Study and Contingent Approved Study that is included in Exhibit B or C
of the 2007-2009 Clinical Development Plan as of the date of this Amendment
No. 2, as set forth in such Exhibit B or C, as the case may be, (ii) subject to
Sections 4.3(b)(ii) and 4.3(h)(ii), each budget for Development Costs for each
Approved Study and Contingent Approved Study that is included in Exhibit A of
the 2007-2009 Clinical Development Plan as of the date of this Amendment No. 2
as set forth in such Exhibit A; and (iii) each budget for Development Costs for
each Proposed Study or Emergency Study that becomes an Approved Study or a
Contingent Approved Study that is not set forth in the 2007-2009 Clinical
Development Plan as of the date of this Amendment No. 2 that is included in a
subsequent Clinical Development Plan and that is approved in accordance with the
provisions of this Agreement, in each case as such Clinical Budget may be
modified or amended from time to time in accordance with the provisions of this
Agreement. Each Clinical Budget shall set forth the approved aggregate
Development Costs through completion for each Approved Study and each Contingent
Approved Study included in the Clinical Development Plan (including the budgeted
Development Costs for each such Approved Study and Contingent Approved Study for
each calendar year included in the applicable Clinical Development Plan and the
estimated Development Costs, if any, for each subsequent calendar year through
completion) and shall include the other cost information required by
Exhibit 1.20 for each Approved Study and each Contingent Approved Study included
in the Clinical Development Plan.

1.20 "Clinical Development Plan" shall mean (a) the 2007-2009 Clinical
Development Plan and (b) each subsequent Clinical Development Plan prepared and
approved in accordance with the provisions of Sections 4.3(c) and 4.3(f), in
each case as such Clinical Development Plan may be modified or amended from time
to time to add or delete an Approved Study or a Contingent Approved Study or
otherwise modified or amended in accordance with the provisions of Sections
2.1(b)(ii), (iii), (iv) and (v). Each Clinical Development Plan shall include
for each Approved Study and Contingent Approved Study (other than any Clinical
Study that was included in a Clinical Development Plan prior to the date of this
Amendment No. 2), all the information required by Exhibit 1.20 including a
Clinical Budget.

1.20A "2007-2009 Clinical Development Plan" shall mean the Clinical Development
Plan set forth in Exhibit 1.20A that has been agreed to among the Parties as of
the date of this Amendment No. 2, as the same may be amended or modified in
accordance with the provisions of this Agreement."

        (c)   Section 1 of the Agreement is further amended by inserting the
following definitions in alphabetical order:

"1.5A "Alliance Committee" shall have the meaning assigned to such term in
Section 2.10(a).

1.10A "Approved Study" shall mean a study that the Parties have agreed shall be
conducted and jointly funded in accordance with Section 4.6, which comprises
(a) each study designated as an Approved Study in the 2007-2009 Clinical
Development Plan as of the date of this Amendment No. 2 and (b) each other study
that shall be designated as

2

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an Approved Study in a subsequent Clinical Development Plan in accordance with
the procedures set forth in Section 4.3(f), each Proposed Study or Emergency
Study that is added to the then-current Clinical Development Plan as an Approved
Study in accordance with the provisions of Sections 4.3 (f) or 4.3 (i), as the
case may be, and each Contingent Approved Study that shall be designated as an
Approved Study in accordance with the provisions of Section 4.3(h).

1.10B "Attributable Other Party SFI Expenses" shall have the meaning assigned to
such term in Section 7.2(b).

1.20A "Clinical Study" shall mean (a) any clinical study undertaken (i) for
approval of new indications for the Product, (ii) to obtain a compendial
listing, (iii) for the purpose of providing data that will result in a labeling
change for the Product, or (iv) for any other purpose under an IND for the
Product (e.g., Phase I through Phase III studies), (b) any Phase IIIb Clinical
Trial or Phase IV Clinical Trial for the Product, and (c) any non-clinical study
that is (1) required, requested or advised by a Regulatory Authority or
(2) undertaken with the intention to obtain or maintain a regulatory approval or
compendial listing, or to develop and provide additional information for
inclusion in the label for the Product. A clinical study shall be deemed to have
commenced when the first patient in such study is enrolled. For clarity, for
purposes of this Agreement, Clinical Studies do not include clinical trials or
other studies where a Product is used in such study as provided in
Section 4.3(a)(iii).

1.28A "Contingencies" shall mean, with respect to any Contingent Approved Study,
the specific contingencies, decision points, and "go/no go" criteria for the
commencement or continuation of such Contingent Approved Study as set forth in
the Clinical Development Plan for each such Contingent Approved Study.

1.28B "Contingent Approved Study" shall mean a study that the Parties have
unanimously agreed shall be conducted if the Contingencies related to such study
are satisfied in which event the commencement of such study shall be jointly
funded in accordance with Section 4.6, which comprises (a) each study designated
as a Contingent Approved Study in the 2007-2009 Clinical Development Plan as of
the date of this Amendment No. 2 and (b) each other study that shall be
designated as a Contingent Approved Study in a subsequent Clinical Development
Plan in accordance with the procedures set forth in Section 4.3(f) or each
Proposed Study that is added to the then-current Clinical Development Plan as a
Contingent Approved Study in accordance with the provisions of Section 4.3(f).

1.37A "Emergency Study" shall mean a Clinical Study that is to be performed to
respond to a significant patient safety issue, a significant toxicity management
issue or a request from a Regulatory Authority to conduct a Clinical Study
relating to a significant patient safety issue or a significant toxicity
management issue.

1.54A "Incremental SFI Profit Or Loss" means Net Sales in North America of the
Products that are attributable to a given Successful Indication for a given
period, less the following costs, if any, incurred by the applicable
Non-Proposing Party or any of its Affiliates for such Products that are
attributable or reasonably allocable to such Successful Indication with respect
to such period, including without limitation: [*]. For purposes of this
Section 1.54A, where the definition of [*] refers to "Japan", such reference to
"Japan" will be replaced by North America.

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*Omitted and filed separately pursuant to a request for confidential treatment
submitted to the Securities and Exchange Commission.

3

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1.60A "Japan Co-Commercialization Agreements" shall mean the Amended and
Restated Co-Development and Co-Commercialization Agreement for Erbitux in Japan
among Bristol-Myers Squibb Company, Bristol-Myers K.K., E.R. Squibb & Sons, LLC,
Merck KGaA, Merck Ltd. and ImClone Systems Incorporated and the BMS-ImClone
Japan Agreement among Bristol-Myers Squibb Company, Bristol-Myers K.K., E.R.
Squibb & Sons, LLC and ImClone Systems Incorporated, in each case as referenced
in the Letter of Intent Regarding the Japan Co-Commercialization Agreements.

1.60B "Letter of Intent Regarding the Japan Co-Commercialization Agreements"
means the letter executed by the Parties as of the date of this Amendment No. 2
with respect to certain matters related to the co-development and co-promotion
of the Compound in Japan, including the negotiation and agreement of the Japan
Co-Commercialization Agreements.

1.72A "Material Modification" shall have the meaning assigned to such term in
Section 2.1(b)(v).

1.77A "Non-Proposing Party" shall have the meaning assigned to such term in
Section 4.3(g)(i).

1.88A "Phase IIIb Clinical Trial" means a human clinical trial of a Compound or
Product for an indication that (a) is not required for receipt of Regulatory
Approval for such indication for a country but which may be useful in providing
additional drug profile data in support of such Regulatory Approval (whether the
trial is commenced prior to or after receipt of such Regulatory Approval), or
(b) is required, requested or advised by a Regulatory Authority as a condition
of, or in connection with, obtaining or maintaining such Regulatory Approval
(whether the trial is commenced prior to or after receipt of such Regulatory
Approval). For clarity, for purposes of this Agreement, Phase IIIb Clinical
Trials do not include clinical trials or other studies where a Product is used
in such study as provided in Section 4.3(a)(iii).

1.88B "Phase IV Clinical Trial" means a product support human clinical trial, or
other test or study, of a Compound or Product for an indication that is either
(a) commenced after receipt of the initial Regulatory Approval for such
indication in the country for which such trial is being conducted and that is
conducted within the parameters of the Regulatory Approval for the Compound or
Product for such indication (and which may include investigator-sponsored
clinical trials ("ISTs")), but shall not include any Phase IIIb Clinical Trial
or (b) is an IST that does not fall within the approved label for a Product.
Phase IV Clinical Trials may include trials or studies conducted in support of
pricing/reimbursement, epidemiological studies, life cycle management, modeling
and pharmacoeconomic studies, post-marketing surveillance studies, outcome
research studies and health economics studies. For clarity, for purposes of this
Agreement, Phase IV Clinical Trials do not include clinical trials or other
studies where a Product is used in such study as provided in
Section 4.3(a)(iii).

1.91A "Proposed Study" shall have the meaning assigned to such term in
Section 4.3(e).

1.91B "Proposing Party" shall have the meaning assigned to such term in
Section 4.3(g)(i).

1.95 "Release and Waiver" shall mean the Release and Waiver between the Parties
dated as of the date of this Amendment No. 2.

1.96A "Responsible Party" shall mean (a) with respect to any Approved Study or
Contingent Approved Study, the Party responsible for conducting such study or,
if such study is to be conducted by a CRO, the Party responsible for overseeing
the conduct of

4

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such study, in each case as set forth in the Clinical Development Plan and
(b) with respect to any Sole-Funded SFI Registrational Study, the Proposing
Party for such Sole-Funded SFI Registrational Study.

1.99A "Scientific Expert" means a disinterested individual without any
conflict-of-interest who is not affiliated with either Party and who has
appropriate scientific, technical or regulatory expertise to resolve any
disputes referred to him or her under this Agreement. A Scientific Expert shall
not be or have been at any time within the previous five years an Affiliate,
employee, consultant, officer or director of either Party or any of its
respective Affiliates.

1.99B "Selected Scientific Expert" shall have the meaning assigned to such term
in Section 2.1(d)(vi).

1.99C "SFI" shall have the meaning assigned to such term in Section 4.3(g)(ii).

1.99D "SFI Net Canadian Sales" shall have the meaning assigned to such term in
Section 7.2(b).

1.99E "SFI Net U.S. Sales" shall have the meaning assigned to such term in
Section 7.2(b).

1.101A "Side Letter" shall mean the Side Letter between the Parties dated as of
the date of this Amendment No. 2.

1.101C "Sole-Funded SFI Registrational Study" shall mean a Clinical Study solely
funded individually by either the Company or ERS subject to the provisions of
Section 4.3(g).

1.102A "Specified Phase III Study" shall have the meaning assigned to such term
in 4.3(g)(i).

1.102B "Specified Signal Finding Study" shall have the meaning assigned to such
term in 4.3(g)(i).

1.104A "Successful Indication" shall have the meaning assigned to such term in
Section 4.3(g)(ii)."

        (d)   Exhibits 4.3(A), 4.3(B), 8.12(b)(i) and 8.12(b)(ii) are hereby
deleted in their entirety.

        (e)   New Exhibits 1.20 and 1.20(A) and Schedule 4.3(g)(i) are hereby
added to the Agreement in the form of Exhibits 1.20 and 1.20(A) and
Schedule 4.3(g)(i) to this Amendment No. 2.

        (f)    The definition of "Development Costs" included in the Financial
Appendix is hereby deleted in its entirety and replaced with the following:

"'Development Costs'

        (a)   In each of North America and Japan, "Development Costs" means the
development costs incurred by each Party with respect to a Product in North
America or Japan, as the case may be, from the Effective Date of the Agreement
through the later of (i) the date of Registration (including thereafter costs to
maintain or expand such Registration) of such Product in the Field in North
America or Japan, as the case may be, or (ii) the date of termination of
development efforts of such Product in the Field, as applicable in North America
or Japan. Such costs shall comprise those costs incurred to obtain, maintain
and/or expand the relevant authorization and/or ability to manufacture,
formulate, fill, use, ship, sell and/or distribute the relevant Product in
commercial quantities to Third Parties in North America or Japan, as the case
may be.

5

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        (b)   In each of North America and Japan, "Development Costs" shall
include, without limitation, costs of research or development including costs of
studies on the toxicological, pharmacokinetical, metabolical or clinical aspects
of a Product conducted internally or by individual investigators or consultants
necessary for the purpose of obtaining, maintaining and/or expanding marketing/
pricing approval of a Product (including costs of Clinical Studies), costs for
preparing, submitting, reviewing or developing data or information for the
purpose of submission to a governmental authority to obtain, maintain and/or
expand marketing/pricing approval of a Product, and applicable Allocable
Overhead.

        (c)   In each of North America and Japan, "Development Costs" shall also
include, without limitation, expenses for data management, statistical designs
and studies, document preparation, and other administration expenses associated
with the clinical testing program or post-marketing studies required to maintain
product approvals.

        (d)   For a given Approved Study or Contingent Study included in the
Clinical Development Plan or a Sole-Funded SFI Registrational Study, Development
Costs shall include the internal FTE Costs (for which a Party's internal FTE
Rate shall be calculated based on the relevant Parties' costs set forth in Annex
I to the Financial Appendix, which shall be reviewed and mutually agreed by ERS
and the Company prior to the beginning of each new calendar year beginning with
calendar year 2008) and direct out-of-pocket costs that are paid or incurred by
a Party or any of its Affiliates that are attributable or reasonably allocable
to such Approved Study, Contingent Approved Study or Sole-Funded SFI
Registrational Study, including without limitation:

          (i)  the internal FTE Costs and direct out-of-pocket costs incurred in
connection with the planning and conduct of any such Approved Study, Contingent
Approved Study or Sole-Funded SFI Registrational Study, including grant costs
and contract research organization ("CRO") costs;

         (ii)  the Fully-Burdened Manufacturing Cost for (1) Compound or Product
used in such Approved Study, Contingent Approved Study or Sole-Funded SFI
Registrational Study, and (2) the manufacture, purchase or packaging of
comparators, placebo or other clinical supplies for use in such Approved Study,
Contingent Approved Study or Sole-Funded SFI Registrational Study (with the
manufacturing costs for such comparators, placebo or clinical supplies that are
(A) manufactured by a Party or its Affiliates to be determined in the same
manner as Manufacturing Costs are determined for such Product or (B) purchased
by a Party or its Affiliates from a Third Party based on the actual cost of
purchase), as well as the reasonable direct costs and expenses of disposal of
drugs and other supplies used in such Approved Study, Contingent Approved Study
or Sole-Funded SFI Registrational Study;

        (iii)  regulatory expenses (including internal FTE costs and direct
out-of-pocket costs) incurred that directly relate to such Approved Study,
Contingent Approved Study or Sole-Funded SFI Registrational Study;

        (iv)  costs of recruitment initiatives for such Approved Study,
Contingent Approved Study or Sole-Funded SFI Registrational Study; and

         (v)  Allocable Overhead relating to such Approved Study, Contingent
Approved Study or Sole-Funded SFI Registrational Study.

If any cost or expense is specifically identifiable or reasonably allocable to
more than one activity set forth above, such cost or expense shall only be
counted as Development Costs with respect to one of such activities, provided
that, other than with respect to any cost or expense incurred in connection with
the obtaining, maintaining and/or expanding marketing/pricing

6

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approval of a Product, no expense that is specifically identifiable or
reasonably allocable as a Marketing Cost may be counted as a Development Cost.

        (e)   Each Party will use its respective project accounting systems and
will review and approve its respective project accounting systems and
methodologies with the other Parties, provided that in determining the amount of
Development Costs incurred in a given year for purposes of the cost sharing
provisions of Section 4.6, the Parties will use the cash basis of accounting."

        (g)   New Annex I to the Financial Appendix is hereby added to the
Agreement in the form of Annex I to this Amendment No. 2.

        (h)   The definition of "Marketing Costs" included in the Financial
Appendix is hereby amended by inserting the following at the end thereof:

        "(d) "Marketing Costs" will specifically exclude the costs of [*]."

--------------------------------------------------------------------------------

*Omitted and filed separately pursuant to a request for confidential treatment
submitted to the Securities and Exchange Commission.

7

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        SECTION 2.    Amendments to Section 2 of the Agreement.

        (a)   Section 2.1(b) is hereby deleted in its entirety and replaced with
the following:

        "(b) Responsibilities.    The JEC shall perform the following functions:

          (i)  oversee the development and commercialization of the Compounds
and Products pursuant to the terms of this Agreement;

         (ii)  review and approve, pursuant to Section 4.3(f), each Clinical
Development Plan, including the Clinical Budget for each Approved Study and
Contingent Approved Study included in such Clinical Development Plan;

        (iii)  review and approve, pursuant to Section 4.3(f) or 4.3(i), as
applicable, each Proposed Study and each Emergency Study proposed to be added as
an Approved Study or a Contingent Approved Study to the then-current Clinical
Development Plan pursuant to Section 4.3(e) or 4.3(i), as applicable, including
the related Clinical Budget for such Proposed Study or Emergency Study;

        (iv)  (A) review and approve, pursuant to Section 4.3(h), the
determination that either (1) each of the Contingencies applicable to a
Contingent Approved Study has been satisfied and such Contingent Approved Study
shall become an Approved Study or (2) at least one of the Contingencies related
to a Contingent Approved Study has failed to be satisfied and such Contingent
Approved Study shall be removed from the Clinical Development Plan; and
(B) review and approve, pursuant to Section 4.3(h), the protocol and updated
Clinical Budget for each Contingent Approved Study that shall become an Approved
Study;

         (v)  review and approve (A) any amendments or modifications to any
Approved Study or Contingent Approved Study included in the then-current
Clinical Development Plan that would reasonably be expected to result in an
increase in the aggregate Clinical Budget through the completion of such
Approved Study or Contingent Approved Study, as applicable, of [*] or more or
(B) any other material modification or amendment to any Approved Study or
Contingent Approved Study, including (1) any delay in the expected start date of
such Approved Study or Contingent Approved Study by more than [*], (2) any
change of [*] or more in the number of patients enrolled or to be enrolled in
such approved Study or Contingent Approved Study, (3) a change in the primary or
secondary endpoints or any other key provisions of the study protocol design
(including study power), publication strategy or data analysis relating to such
Approved Study or Contingent Approved Study, (4) any modification or amendment
to the Contingencies required to be satisfied for any Contingent Approved Study
to become an Approved Study or (5) the early termination of an Approved Study or
Contingent Approved Study (any such amendment or modification in clause (A) or
(B) of this Section 2.1(b)(v), a "Material Modification"), provided that this
Section 2.1(b)(v) shall not apply to the termination of a Contingent Approved
Study as a result of failure to satisfy the Contingencies applicable to such
Contingent Approved Study (which is the subject of Section 2.1(b)(iv)), provided
further that, pending the JEC approval of early termination under this
Section 2.1(b)(v)(B)(5), the Responsible Party for an Approved Study or
Contingent Approved Study may suspend such Approved Study or Contingent Approved
Study, as the case may be, if it believes that failure to do so would jeopardize
the welfare or safety of patients;

        (vi)  at each meeting of the JEC review a comparison of the actual
expenses to the budgeted expenses for the year-to-date (including Development
Costs for each Approved

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*Omitted and filed separately pursuant to a request for confidential treatment
submitted to the Securities and Exchange Commission.

8

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Study and each Contingent Approved Study), as current as practicable to a date
immediately prior to the date of the meeting;

       (vii)  review and evaluate the progress of the other Committees;

      (viii)  review and take action on any other matters within the scope of
the authority of another Committee that are referred to the JEC by such other
Committee;

        (ix)  review and, if unanimously agreed, reallocate spending from the
Marketing Budget to the Clinical Budget;

         (x)  establish and empower a finance committee, which shall consist of
an equal number of representatives from each of the Company and BMS (the
"Finance Committee") to advise the JEC and make recommendations to the JEC for
the areas it has responsibility as provided in Section 2.2;

        (xi)  at least once each year, meet with each of the other Committees
(which meetings do not need to include all of the other Committees at the same
meeting);

       (xii)  in accordance with the procedures established in Section 2.1(d),
resolve disputes, disagreements and deadlocks unresolved by the other
Committees; and

      (xiii)  have such other responsibilities as may be assigned to the JEC
pursuant to this Agreement or as may be mutually agreed upon by the Parties from
time to time."

        (b)   Section 2.1(d) of the Agreement is hereby deleted in its entirety
and replaced with the following:

        "(d) Decision-making.

          (i)  The JEC may make decisions with respect to any subject matter
that is subject to the JEC's decision-making authority and functions as set
forth in Section 2.1(b). Except as otherwise specified in Section 2.1(d)(ii),
(iii), (iv), (v) or (vii), all decisions of the JEC shall be made by unanimous
vote or written consent, with the Company and BMS each having, collectively, one
vote in all decisions. The JEC shall use reasonable best efforts to resolve the
matters within its roles and functions or otherwise referred to it.

         (ii)  Subject to the provisions of Section 2.1(d)(vii), with respect to
any Critical Issue (other than a Critical Issue that relates to a decision to be
made pursuant to Section 2.1(b)(ii), (iii), (iv), (v) or (ix)), if the JEC
cannot reach consensus within five business days after the matter has been
brought to the JEC's attention, the matter shall be referred on the sixth
business day: (A) if the matter is the subject of a deadlock arising in the PDC
and is not the subject of Section 4.8 or 4.9, to the co-chairperson of the JEC
designated by the Company for resolution, provided that any decision made by the
co-chairperson of the JEC designated by the Company may not increase the
aggregate Clinical Budget for such Approved Study or Contingent Approved Study
through completion by [*] or more; (B) if the matter is the subject of a
deadlock arising in the JCC (other than a matter under Section 2.4(b)(xiv) with
respect to Trademarks), to the co-chairperson of the JEC designated by BMS for
resolution, provided that any decision made by the co-chairperson of the JEC
designated by BMS may only increase or decrease the overall amount of the
relevant Marketing Budget within the ranges provided in and otherwise in
accordance with Section 5.2; (C) if the matter is under Section 2.4(b)(xiv) with
respect to Trademarks and is subject of a deadlock arising in the JCC, to the
co-chairperson of the JEC designated by the Company for resolution; and
(D) except as provided in Section 8.12(f), if the matter is the subject of a
deadlock arising in the JMC, to the co-chairperson of the JEC designated by the
Company for resolution. In the event that the co-chairperson of a Party
designated to resolve a dispute

--------------------------------------------------------------------------------

*Omitted and filed separately pursuant to a request for confidential treatment
submitted to the Securities and Exchange Commission.

9

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under this Section 2(d)(ii) is not immediately available, then such matter shall
be referred to a senior executive officer of such Party who has been designated
by such Party for such resolution.

        (iii)  Subject to the provisions of Section 2.1(d)(vii), with respect to
all other matters that are subject to the JEC's decision-making authority (other
than any matter that relates to a decision to be made pursuant to
Section 2.1(b)(ii), (iii), (iv), (v) or (ix)), if the JEC cannot reach consensus
within 20 business days after it has met and attempted to reach such consensus,
the matter shall be referred on the twenty-first business day: (A) if the matter
is the subject of a deadlock arising in the PDC and is not the subject of
Section 4.8 or 4.9, to the co-chairperson of the JEC designated by the Company
for resolution, provided that any decision made by the co-chairperson of the
Company may not increase the aggregate Clinical Budget for such Approved Study
or Contingent Approved Study through completion by [*] or more; (B) if the
matter is the subject of a deadlock arising in the JCC (other than a matter
under Section 2.4(b)(xiv) with respect to Trademarks), to the co-chairperson of
the JEC designated by BMS for resolution, provided that any decision made by the
co-chairperson of BMS may not increase or decrease the overall amount of the
relevant Marketing Budget within the ranges provided in accordance and otherwise
in accordance with Section 5.2; (C) if the matter is under
Section 2.4(b)(xiv) with respect to Trademarks and is the subject of a deadlock
arising in the JCC, to the co-chairperson of the JEC designated by the Company
for resolution; and (D) except as provided in Section 8.12(f), if the matter is
the subject of a deadlock arising in the JMC, to the co-chairperson of the JEC
designated by the Company for resolution.

        (iv)  Subject to the provisions of Section 2.1(d)(vii), in the event of
a deadlock of the JEC with respect to a Critical Issue (other than a Critical
Issue that relates to a decision to be made pursuant to Section 2.1(b)(ii),
(iii), (iv), (v) or (ix)) that is not resolved pursuant to
Section 2.1(d)(ii) and the matters underlying such deadlock fall into the class
of disputes that may be arbitrated by the Parties in accordance with
Section 16.13, then such matters shall be resolved pursuant to the Accelerated
Arbitration Provisions of Section 16.13(b). Subject to the provisions of
Section 2.1(d)(vii), in the event of a deadlock of the JEC with respect to any
other matters that are not resolved pursuant to Section 2.1(d)(iii) and such
matters fall into the class of disputes that may be arbitrated by the Parties in
accordance with Section 16.13, then such matters shall be resolved pursuant to
Section 16.13(a).

         (v)  Subject to the provisions of Section 2.1(d)(vii), in the event of
a deadlock of the JEC with respect to any matter that relates to a decision to
be made pursuant to Section 2.1(b)(ii), (iii), (iv), (v) or (ix), such deadlock
shall be resolved solely as follows:

        (A)  if the matter relates to a deadlock under Section 2.1(b)(ii), the
new Clinical Development Plan shall be deemed to include only (1) Approved
Studies, (2) Contingent Approved Studies for which there has not been a
determination pursuant to Section 2.1(b)(iv) to remove such Contingent Approved
Study from the Clinical Development Plan, and (3) any other studies that the
Parties have agreed unanimously in accordance with the provisions of
Section 4.3(f) should be included as an Approved Study or Contingent Approved
Study in the new Clinical Development Plan;

--------------------------------------------------------------------------------

*Omitted and filed separately pursuant to a request for confidential treatment
submitted to the Securities and Exchange Commission.

10

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        (B)  if the matter relates to a deadlock regarding an Emergency Study
under Section 2.1(b)(iii), the Emergency Study shall become an Approved Study
and shall be added to the then-current Clinical Development Plan, provided that
if the deadlock relates to the scientific design of the Emergency Study, the
Parties shall seek the advice of the Regulatory Authority on the appropriate
scientific design of the Emergency Study and shall implement the Regulatory
Authority's recommendations;

        (C)  if the matter relates to a deadlock regarding a Proposed Study
under Section 2.1(b)(iii), the Proposed Study shall not become an Approved Study
or a Contingent Approved Study;

        (D)  (1) if the matter relates to a deadlock under
Section 2.1(b)(iv) (other than with respect to approval of an updated Clinical
Budget), the matter shall be submitted to binding arbitration by a Scientific
Expert pursuant to Section 2.1(d)(vi) and (2) if the matter relates to a
deadlock under Section 2.1(b)(iv) with respect to approval of an updated
Clinical Budget, such matter shall be resolved pursuant to the Accelerated
Arbitration Provisions of Section 16.13(b) based on the agreed protocol for such
Contingent Approved Study, provided that such arbitration may not result in an
increase in the Clinical Budget of more than [*] in excess of the Clinical
Budget for such Contingent Approved Study in the Clinical Development Plan as of
the date of this Amendment No. 2;

        (E)  if the matter relates to a deadlock regarding a Material
Modification under Section 2.1(b)(v), the amendment or modification shall not be
made; and

        (F)  if the matter relates to a deadlock regarding the reallocation of
funds under Section 2.1(b)(ix), the reallocation shall not be made.

For the avoidance of doubt, a deadlock of the JEC with respect to any matter
that relates to a decision to be made pursuant to Section 2.1(b)(ii), (iii),
(iv), (v) or (ix) shall not be a dispute that may be arbitrated pursuant to
Section 16.13.

        (vi)  In the event of a deadlock of the JEC with respect to a matter
described in Section 2.1(d)(v)(D), the matter shall be referred for arbitration
to a Scientific Expert who is mutually agreed by the Parties. If the Parties
cannot agree on a mutually acceptable Scientific Expert within 30 calendar days
after the JEC has determined that it can not reach agreement, then within five
business days after the expiration of such 30-calendar day period, each of ERS
and the Company shall appoint one Scientific Expert who shall jointly select a
third Scientific Expert within five business days after the last to occur of
their respective appointments to arbitrate the referred matter. The Scientific
Expert mutually agreed by the Parties or, if the Parties cannot agree, the third
Scientific Expert selected by the Party-appointed Scientific Experts is referred
to as the "Selected Scientific Expert". ERS and the Company shall instruct the
Selected Scientific Expert to render a determination of any such dispute within
15 business days after his selection. The dispute shall be resolved by
submission of documents unless the Selected Scientific Expert determines that an
oral hearing is necessary. The Selected Scientific Expert shall, within the
overall 15 business day time constraint, determine what shall be conclusively
deemed to be fair and appropriate deadlines for submitting documents and dates,
if any, of oral hearings. Each Party shall pay its own expenses of arbitration,
and the expenses of the Scientific Experts shall be equally shared between ERS
and the Company. Any decision rendered by the Selected Scientific Expert shall
be final and binding upon the Parties. Application may be made to any court
having

--------------------------------------------------------------------------------

*Omitted and filed separately pursuant to a request for confidential treatment
submitted to the Securities and Exchange Commission.

11

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jurisdiction for a judicial acceptance of the decision and an order of
enforcement, as the case may be. This Section 2.1(d)(vi) shall not prohibit a
Party from seeking injunctive relief from a court of competent jurisdiction in
the event of a breach or prospective breach of this Agreement by any other Party
which would cause irreparable harm to the first Party.

       (vii)  If the JEC cannot reach consensus with respect to any matter that
is subject to the JEC's decision-making authority, and the co-chairs of the JEC
unanimously agree, the matter shall be referred first to the Alliance Committee
for review in accordance with the provisions of Section 2.10 before the
provisions of Section 2.1(d)(ii), (iii), (iv) or (v), as applicable, shall be
invoked. In the event of such referral, the periods of time set forth in
Section 2.1(d)(ii), (iii), (iv) or (v), as applicable, shall be tolled during
the period of the Alliance Committee's review of the referred matter. If within
five business days (in the case of any referred matter that is to be resolved
pursuant to Section 2.1(d)(ii)) or 20 business days (in the case of any referred
matter that is to be resolved pursuant to Section 2.1(d)(iii), (iv) or (v))
after having received the Alliance Committee's response, the JEC again cannot
reach consensus, the matter shall be resolved in accordance with
Section 2.1(d)(ii), (iii), (iv) or (v), as applicable.

      (viii)  For all purposes under this Agreement, any decision made pursuant
to this Section 2.1(d) shall be deemed to be the decision of the JEC."

        (c)   Section 2.3(b) is hereby deleted in its entirety and replaced with
the following:

        "(b) Responsibilities.    The PDC shall perform the following functions:

          (i)  review and recommend, pursuant to Section 4.3(f), to the JEC for
consideration and approval each Clinical Development Plan, including the related
Clinical Budget for each Approved Study and Contingent Approved Study included
in such Clinical Development Plan;

         (ii)  review and recommend, pursuant to Section 4.3(f) or 4.3(i), as
applicable, to the JEC for consideration and approval each Proposed Study and
each Emergency Study proposed to be added as an Approved Study or a Contingent
Approved Study to the then-current Clinical Development Plan pursuant to
Section 4.3(e) or 4.3(i), as applicable, including the proposed Clinical Budget
for such Proposed Study or Emergency Study;

        (iii)  (A) review and recommend, pursuant to Section 4.3(h), to the JEC
that either (1) each of the Contingencies applicable to a Contingent Approved
Study has been satisfied and such Contingent Approved Study should become an
Approved Study or (2) that at least one of the Contingencies related to a
Contingent Approved Study has failed to be satisfied and such Contingent
Approved Study should be removed from the Clinical Development Plan; and
(B) review and recommend, pursuant to Section 4.3(h), the protocol and updated
Clinical Budget for each Contingent Approved Study that shall become an Approved
Study;

        (iv)  oversee the implementation of the Clinical Development Plans and
any Sole-Funded SFI Registrational Studies;

         (v)  review and approve or, in the case of any Material Modification,
recommend to the JEC for approval any amendment or modification to the Clinical
Development Plan;

        (vi)  at each meeting of the PDC review a comparison of the actual
Development Costs incurred to the budgeted Development Costs for the
year-to-date for each Approved Study and each Contingent Approved Study, as
current as practicable to a date immediately prior to the date of the meeting;

       (vii)  review and evaluate progress of each Approved Study or Contingent
Approved Study and any Sole-Funded SFI Registrational Studies, provided that the
PDC shall not have authority to make any determination that any Party is in
breach of this Agreement;

12

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      (viii)  review and approve all compassionate use of Products;

        (ix)  review and approve the joint publication strategy together with
the JCC, and take the lead in coordinating such joint review and approval; and

         (x)  have such other responsibilities as may be assigned to the PDC
pursuant to this Agreement or as may be mutually agreed upon by the Parties from
time to time."

        (d)   Section 2.3(d) is hereby deleted in its entirety and replaced with
the following:

        "(d) Decision-making.

          (i)  The PDC may make decisions with respect to any subject matter
that is subject to the PDC's decision-making authority and functions as set
forth in Section 2.3(b). All decisions of the PDC shall be made by unanimous
vote or written consent, with the Company and BMS each having, collectively, one
vote in all decisions.

         (ii)  If, with respect to any matter related to a decision under
Section 2.3(b)(iii) (other than with respect to approval of an updated Clinical
Budget), the PDC cannot reach consensus within twenty business days after it has
first met and attempted to reach such consensus, the matter shall be referred on
the twenty-first business day to each Party's most senior scientific officer for
review. If within 20 business days after having received the matter from the
PDC, such officers cannot reach agreement, the matter shall be referred on the
twenty-first business day to the Alliance Committee for review and comment in
accordance with Section 2.10. If within twenty business days after having
received the Alliance Committee's response, the PDC again cannot reach
consensus, the matter should be referred on the twenty-first business day to the
JEC for resolution.

13

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        (iii)  If, with respect to a Critical Issue that is subject to the PDC's
decision-making authority (other than a Critical Issue that relates to a
decision pursuant to Section 2.3(b)(iii)(A)), the PDC cannot reach consensus
within five business days after it has first met and attempted to reach such
consensus, the matter shall be referred on the sixth business day to the
Alliance Committee for review and comment in accordance with Section 2.10. If
within five business days after having received the Alliance Committee's
response the PDC again cannot reach consensus, the matter shall be referred on
the sixth business day to the JEC.

        (iv)  If, with respect to any other matter that is subject to the PDC's
decision-making authority, the PDC cannot reach consensus within 20 business
days after it has first met and attempted to reach such consensus, the matter
shall be referred on the twenty-first business day to the Alliance Committee for
review and comment in accordance with Section 2.10. If within 20 business days
after having received the Alliance Committee's response, the PDC again cannot
reach consensus, the matter shall be referred on the twenty-first business day
to the JEC for resolution.

         (v)  For all purposes under this Agreement, any decision made pursuant
to this Section 2.3(d) shall be deemed to be the decision of the PDC."

        (e)   Section 2.4(b) of the Agreement is hereby deleted in its entirety
and replaced with the following:

        "(b) Responsibilities.    The JCC shall perform the following functions:

          (i)  oversee the preparation and implementation of the Marketing
Plans;

         (ii)  oversee and coordinate the sales efforts of ERS and the Company;

        (iii)  review and approve Marketing Plans;

        (iv)  discuss the state of the markets for Products in the Territory and
opportunities and issues concerning the commercialization of the Products,
including consideration of marketing and promotional strategy, marketing
research plans, labeling, Product positioning and Product profile issues, to
determine in which countries in the Territory to launch Products, the priority
for same and the amount and kind of marketing and selling effort appropriate, in
accordance with the Marketing Plans;

         (v)  review and approve the total annual budget for all Phase IV
Clinical Trials, but not the budget or protocol for the individual studies
themselves which must be approved by the PDC and the JEC pursuant to
Section 4.3(f);

        (vi)  review and approve all pricing decisions and managed care
contracting strategies, in accordance with the Marketing Plans;

       (vii)  review and approve all indigent care use of Products;

      (viii)  periodically review sales mix of Products sold by ERS through
various customer channels;

        (ix)  review and approve allocations within the Marketing Budgets, from
time to time;

         (x)  review and approve each subsequent marketing budget in accordance
with Section 5.2(c);

        (xi)  review data and reports arising from and generated in connection
with the commercialization of the Products, including, but not limited to the
Marketing Plans, Marketing Budgets and sales forecasts;

14

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       (xii)  at each meeting of the JCC, review a comparison of actual sales
and marketing expenses to the budgeted expenses in the relevant Marketing Budget
for the year-to-date, as current as practicable to a date immediately prior to
the date of the meeting;

      (xiii)  review and approve the general guidelines applicable to particular
Products to be followed in the development of promotional materials and
promotional activities to be used by ERS and the Company in the promotion of
such Products (such guidelines to be consistent with the then-current Marketing
Plan applicable to such Products);

      (xiv)  consider and select Trademarks to be used for the marketing and
sale of the Products in each country in the Territory;

       (xv)  review and approve the joint publication strategy together with the
PDC;

      (xvi)  evaluate and determine the existence or non-existence of a
Co-Promotion Problem referred to the JCC in accordance with Section 5.6(e); and

     (xvii)  have such other responsibilities as may be assigned to the JCC
pursuant to this Agreement or as may be mutually agreed upon by the Parties from
time to time."

        (f)    Section 2.4(d) is hereby deleted in its entirety and replaced
with the following:

        "(d) Decision-making.

          (i)  The JCC may make decisions with respect to any subject matter
that is subject to the JCC's decision-making authority and functions as set
forth in Section 2.4(b). All decisions of the JCC shall be made by unanimous
vote or written consent, with the Company and BMS each having, collectively, one
vote in all decisions. If, with respect to a Critical Issue that is subject to
the JCC's decision-making authority, the JCC cannot reach consensus within five
business days after it has first met and attempted to reach such consensus, the
matter shall be referred on the sixth business day to the Alliance Committee for
review and comment in accordance with Section 2.10. If within five business days
after having received the Alliance Committee's response, the JCC again cannot
reach consensus, the matter shall be referred on the sixth business day to the
JEC for resolution.

         (ii)  If, with respect to any other matter that is subject to the JCC's
decision-making authority, the JCC cannot reach consensus within 20 business
days after it has first met and attempted to reach such consensus, the matter
shall be referred on the twenty-first business day to the Alliance Committee for
review and comment in accordance with Section 2.10. If within 20 business days
after having received the Alliance Committee's response, the JCC again cannot
reach consensus, the matter shall be referred on the 21st business day to the
JEC for resolution.

        (iii)  For all purposes under this Agreement, any decision made pursuant
to this Section 2.4(d) shall be deemed to be the decision of the JCC."

        (g)   Section 2.5(d) is hereby deleted in its entirety and replaced with
the following:

        "(d) Decision-making.

          (i)  The JMC may make decisions with respect to any subject matter
that is subject to the JMC's decision-making authority and functions as set
forth in Section 2.5(b). All decisions of the JMC shall be made by unanimous
vote or written consent, with the Company and BMS each having, collectively, one
vote in all decisions. If, with respect to a Critical Issue that is subject to
the JMC's decision-making authority, the JMC cannot reach consensus within five
business days after it has first met and attempted to reach such consensus, the
matter shall be referred on the sixth business day to the Alliance Committee for
review and comment in

15

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accordance with Section 2.10. If within five business days after having received
the Alliance Committee's response, the JMC again cannot reach consensus, the
matter shall be referred on the sixth business day to the JEC for resolution.

         (ii)  If, with respect to any other matter that is subject to the JMC's
decision-making authority, the JMC cannot reach consensus within 20 business
days after it has first met and attempted to reach such consensus, the matter
shall be referred on the twenty-first business day to the Alliance Committee for
review and comment in accordance with Section 2.10. If within 20 business days
after having received the Alliance Committee's response, the JMC again cannot
reach consensus, the matter shall be referred on the 21st business day to the
JEC for resolution.

        (iii)  For all purposes under this Agreement, any decision made pursuant
to this Section 2.4(d) shall be deemed to be the decision of the JMC."

        (h)   Section 2.6 is hereby deleted in its entirety and replaced with
the following:

        "2.6    Agenda; Minutes of Committee Meetings.    

        (a)   Each Party shall use reasonable efforts to provide written notice
to the other Party not less than three business days prior to any Committee
meeting of any agenda items it intends to raise at the respective Committee
meeting.

        (b)   Subject to Section 2.6(c), definitive minutes of all Committee
meetings shall be finalized no later than 30 calendar days after the meeting to
which the minutes pertain, as follows:

          (i)  Within ten days after a Committee meeting, the secretary of such
Committee shall prepare and distribute to all members of such Committee and each
Alliance Manager draft minutes of the meeting. Such minutes shall provide a list
of any actions, decisions or determinations approved by such Committee and a
list of any issues yet to be resolved, either within such Committee or through
the relevant escalation process. Without limiting the generality of the
foregoing, all approvals by the JEC with respect to matters under Sections
2.1(b)(ii), (iii), (iv), (v) or (ix), by the PDC with respect to matters under
Sections 2.3(b)(i), (ii), (iii) or (iv) or by JCC with respect to matters under
Section 2.4(b)(i) shall be recorded in the minutes of the related meeting of the
JEC, the PDC or the JCC, as applicable.

         (ii)  The Alliance Managers shall then have ten days after receiving
such draft minutes to collect comments thereon from the Committee members of its
Party and provide them to the secretary of such Committee.

        (iii)  Upon the expiration of such second ten-day period, the Alliance
Managers and the secretary of such Committee shall have an additional ten days
to discuss each other's comments and finalize the minutes. The secretary and
chairperson(s) of such Committee shall each sign and date the final minutes. The
signature of such chairperson(s) and secretary upon the final minutes shall
indicate each Party's assent to the minutes.

        (c)   If at any time during the preparation and finalization of
Committee meeting minutes, the secretary of such Committee and the Alliance
Managers do not agree on any issue with respect to the minutes, such issue shall
be submitted for resolution to the co-chairs of the applicable committee. If the
co-chairs of the applicable committee do not agree within ten business days,
such issue shall be resolved as provided in Section 2.3(d), 2.4(d) or 2.5(d), as
the case may be. The decision resulting from the foregoing process shall be
recorded by the secretary in amended finalized minutes for said meeting. All
other issues in the minutes that are not subject to the foregoing process shall
be finalized within the 30-calendar-day period as provided in Section 2.6(a)."

16

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        (i)    Section 2 is further amended by inserting the following at the
end of the Section:

        "2.10    Alliance Committee.    

        (a)    Members.    Immediately after effectivness of this Amendment
No. 2, the Parties shall establish an alliance committee consisting of the JEC
co-chairs and one additional representative from each of the Company and BMS
(the "Alliance Committee"). Each of the Company and BMS may replace any or all
its representatives on the Alliance Committee at any time upon written notice to
the other in accordance with Section 16.5 of this Agreement.

        (b)    Responsibilities.    The Alliance Committee shall meet and review
any matter referred to it by the JEC, the PDC, the JCC or the JMC pursuant to
Section 2.1(d), 2.3(d), 2.4(d) or 2.5(d), as applicable, within ten business
days of receipt of notice of such matter, and shall make a recommendation to the
referring Committee as to the appropriate resolution of the referred matter. All
recommendations of the Alliance Committee shall be made by unanimous vote or
written consent, with the Company and BMS each having, collectively, one vote in
all decisions. The Alliance Committee's recommendation shall be provided to the
referring Committee within 30 calendar days after the Alliance Committee has
first met and reviewed the matter. If the Alliance Committee cannot reach a
unanimous agreement on a recommendation within 30 calendar days after the
Alliance Committee has first met and reviewed the matter, then, unless the
Alliance Committee shall otherwise unanimously agree and notify the referring
Committee, the Alliance Committee shall be deemed to have responded that it
cannot reach an agreement on a recommendation and the matter shall revert back
to the referring Committee for further action. Minutes of the Alliance Committee
shall not be required unless the Parties' members on the Alliance Committee
otherwise agree, and recommendations of the Alliance Committee need not be
reduced to writing except as the members of the Alliance Committee may
unanimously agree. The Alliance Committee shall not have the power to make any
decisions, and any recommendations of the Alliance Committee shall only be
deemed advisory and for consideration by the applicable referring Committee.

        (c)    Term; Expenses.    The Alliance Committee shall exist until the
termination or expiration of this Agreement, or for such longer period as
necessary to perform the remaining responsibilities assigned to it under this
Agreement. Each Party shall be responsible for all travel and related costs and
expenses for its members and other representatives to attend meetings of, and
otherwise participate on, the Alliance Committee."

        SECTION 3.    Amendment to Section 4.3 of the Agreement.    Section 4.3
of the Agreement is hereby deleted in its entirety and replaced with the
following:

        "4.3    Clinical Development Plans and Clinical Budget.    

        (a)   (i) The Parties intend that there shall be a Clinical Development
Plan prepared each calendar year for the Territory (other than Japan) on a
rolling three-year basis during the term of the Agreement. Each Clinical
Development Plan shall set forth each Approved Study and each Contingent
Approved Study being conducted or to be conducted (subject, in the case of any
Contingent Approved Study, to the satisfaction of all applicable Contingencies)
during the three-year period covered by such Clinical Development Plan. Each
Clinical Development Plan shall include, for each Approved Study and Contingent
Approved Study (other than any Clinical Study that was included in a Clinical
Development Plan prior to the date of this Amendment No. 2), all information
required by Exhibit 1.20, including a Clinical Budget. A Clinical Development
Plan also may include information with respect to Proposed Studies, provided
that the Parties shall not be obligated to conduct any such Proposed Studies and
references in this Agreement to the Clinical Development Plan shall not be
deemed to include any such Proposed Studies.

17

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         (ii)  (A) Except for a Sole-Funded SFI Registrational Study, as
provided in Section 4.3(g), none of the Parties (nor any of their Affiliates)
shall conduct any Clinical Study involving a Compound or Product or using
tissues, fluids or other materials that were obtained from a patient in a
Clinical Study (or that were obtained from patients in a study in furtherance of
the development of the Product that was co-funded by the Parties or was part of
a Clinical Development Plan that existed prior to the date of this Amendment
No. 2) related to the development, commercialization, manufacture, marketing,
pricing or sale of Product in the Territory, unless such Clinical Study shall
have been approved as an Approved Study or a Contingent Approved Study in
accordance with provisions of Section 4.3(f) or an Emergency Study in accordance
with Section 4.3(i).

        (B)  Any Party may, at its own cost and expense and without the consent
of the other Party, conduct a study in furtherance of the research and/or
development of the Compound other than a Clinical Study, provided that if such
study relates to pharmacogenomics, allergy or hypersensitivity reactions related
to the Product, prior to commencement of such study, such Party shall submit a
description of such study for review and comment by the PDC. Such Party may, but
shall not be required to, propose that any such study (other than any study that
falls within the scope of Section 4.3(a)(iii)) be included as an Approved Study
or a Contingent Approved Study in the Clinical Development Plan, provided that,
if such study is proposed but is not approved as an Approved Study or a
Contingent Approved Study in accordance with the provisions of Section 4.3(f),
the proposing Party may proceed with such study at its own risk and expense.
Except as required by applicable law, no Party shall publicly disclose or
publish the results of any study conducted in accordance with this
Section 4.3(a)(ii)(B) without the prior approval of the PDC.

        (iii)  Notwithstanding anything to the contrary set forth in this
Agreement, either Party (or any of its Affiliates) may, at its own cost and
expense and without the consent of the other Party, conduct clinical trials or
any other studies for the development of any other product that is not a
Competing Product and that is owned or controlled by it in which a Product is
used in such study within the labeling approved for such Product by the
Regulatory Authority for the country in which the clinical trial is conducted.

        (iv)  The clinical development plan for Japan shall be prepared in
accordance with the applicable provisions of the Japan Co-Commercialization
Agreements or, if such Japan Co-Commercialization Agreements shall no longer be
in effect, as the Parties shall mutually agree.

        (b)   (i) Upon effectiveness of this Amendment No. 2, the 2007-2009
Clinical Development Plan and the Clinical Budget included in the 2007-2009
Clinical Development Plan shall replace all other pre-existing clinical
development plans and clinical budgets under this Agreement.

         (ii)  The Parties agree that certain matters set forth in the 2007-2009
Clinical Development Plan with respect to Approved Studies that have not yet
been finalized shall be finalized in accordance with the following provisions:

        (A)  For each Approved Study included in Exhibit A of the 2007-2009
Clinical Development Plan as of the date of this Amendment No. 2, the PDC shall
be responsible for finalizing the Clinical Budget and, where the identity of the
Responsible Party is "TBD", determining the Responsible Party, as applicable, as
promptly as practicable. Notwithstanding anything in this Agreement to the
contrary, if the PDC cannot reach consensus with respect to the Clinical Budget
or the

18

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Responsible Party, as applicable, for an Approved Study by August 31, 2007, then
the matter shall be referred to the Alliance Committee for resolution. If the
Alliance Committee cannot reach agreement by September 21, 2007, then the matter
shall be referred to the JEC for resolution. If the JEC cannot reach resolution
by September 30, 2007, such matter shall be resolved pursuant to the Accelerated
Arbitration Provisions of Section 16.13(b) based on the agreed protocol for such
Approved Study, provided that such arbitration may not result in an increase in
(1) the Clinical Budget for any such individual Approved Study of more than [*]
in excess of the Clinical Budget for such Approved Study in the Clinical
Development Plan as of the date of this Amendment No. 2 and (2) the Clinical
Budget for all such Approved Studies of more than [*] in the aggregate in excess
of the Clinical Budget for all Approved Studies in the Clinical Development Plan
as of the date of this Amendment No. 2.

        (B)  For each Approved Study included in Exhibit A of the 2007-2009
Clinical Development Plan as of the date of this Amendment No. 2 for which the
determination whether to use a CRO to conduct such Approved Study is marked
"TBD", such determination shall be made in accordance with the provisions of
Section 4.5(a).

        (iii)  During the 90-calendar-day period following the execution of this
Amendment No. 2, the Parties will review each currently ongoing Phase IV
Clinical Trial (other than the two-week dosing study for Head and Neck Cancer)
to determine whether it can be wound down more quickly or terminated. With
respect to any such Phase IV Clinical Trial that the Parties agree can be wound
down more quickly or terminated, the Responsible Party for such Phase IV
Clinical Trial is hereby authorized to take such action as it shall deem
appropriate to wind-down or terminate such Phase IV Clinical Trial, as
applicable, in accordance with the agreement of the Parties. The other Party
shall cooperate with the Responsible Party in such winding-down or termination,
as applicable.

        (c)   Not later than October 31 of each calendar year during the term of
this Agreement, commencing with and including 2008, the PDC shall develop a
proposed Clinical Development Plan for the three calendar years next following
each such calendar year with the goal of finalizing such proposed Clinical
Development Plan not later than December 15 of such calendar year. A Clinical
Development Plan shall not become finalized unless and until it is approved in
accordance with the provisions of Section 4.3(f).

--------------------------------------------------------------------------------

*Omitted and filed separately pursuant to a request for confidential treatment
submitted to the Securities and Exchange Commission.

19

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        (d)   Unless otherwise unanimously agreed by the Parties pursuant to the
approval process in Section 4.3(f), each subsequent Clinical Development Plan
shall include: (1) each Approved Study (including each Contingent Approved Study
that shall have become an Approved Study in accordance with Section 4.3(h))
unless such Approved Study will have been completed or terminated prior to the
commencement of the subsequent Clinical Development Plan and (2) each Contingent
Approved Study (excluding any Contingent Approved Study for which a
determination has been made in accordance with Section 2.1(b)(iv) that such
Contingent Approved Study shall be removed from the Clinical Development Plan).
Each subsequent Clinical Development Plan shall also include the Proposed
Studies that the Parties agree shall be included as Approved Studies or
Contingent Approved Studies, as the case may be, in such subsequent Clinical
Development Plan in accordance with the provisions of Section 4.3(g). Each
subsequent Clinical Development Plan shall include for each Approved Study and
Contingent Approved Study, all the information required by Exhibit 1.20.

        (e)   Each of ERS and the Company may propose to include a new study as
an Approved Study or a Contingent Approved Study in a subsequent Clinical
Development Plan or to amend any then-current Clinical Developmental Plan to
include a new study as an Approved Study or Contingent Approved Study (any such
proposed new study, a "Proposed Study") by providing written notice to the other
Party, together with the information required by Exhibit 1.20 with respect to
such Proposed Study, including a proposed Clinical Budget (with the Parties to
so approach Merck KGaA to co-fund such Proposed Study if either Party believes
it appropriate to do so, provided that such approach to Merck KGaA shall not
delay such submission of such Proposed Study to the PDC for its review and
recommendation in accordance with Section 4.3(f) by more than 60 calendar days).
The Party seeking to add such Proposed Study also shall promptly provide the
other Party such additional information with respect to the Proposed Study as
the other Party shall reasonably request. The provisions of this Section 4.3(e)
shall not apply to any Emergency Study (which is the subject of Section 4.3(i)).
Such Proposed Study shall not be included in a subsequent Clinical Development
Plan as an Approved Study or Contingent Approved Study or added to the
then-current Clinical Development Plan as an Approved Study or Contingent
Approved Study unless and until it is approved in accordance with the provisions
of Section 4.3(f).

        (f)    In order for a proposed Clinical Development Plan developed
pursuant to Section 4.3(c) to be approved as a Clinical Development Plan or for
a Proposed Study to be approved as an Approved Study or a Contingent Approved
Study and added to the then-current Clinical Development Plan, (i) the PDC must
review and unanimously recommend such proposed Clinical Development Plan or
Proposed Study, as applicable, including all protocols developed for each
Approved Study or Contingent Approved Study to be included in a Clinical
Development Plan, to the JEC for approval, and (ii) the JEC must unanimously
approve such proposed Clinical Development Plan or Proposed Study, as
applicable, including all protocols developed for each Approved Study or
Contingent Approved Study to be included in a Clinical Development Plan, all in
accordance with the provisions of Sections 2.1(b)(ii) and (iii) and
2.3(b)(i) and (ii). Each Party can withhold its consent in its sole and absolute
discretion to the inclusion of any Proposed Study in a proposed Clinical
Development Plan or the approval of any Proposed Study to be added to the
then-current Clinical Development Plan.

        (g)   (i) If any of the Contingent Approved Studies set forth on
Schedule 4.3(g)(i) (each a "Specified Phase III Study") shall not become an
Approved Study pursuant to Section 4.3(h) but the corresponding Approved Study
set forth on Schedule 4.3(g)(i) (each, a "Specified Signal Finding Study")
produced positive results (e.g., it demonstrated a sufficient signal in
prolongation of Progression Free Survival ("PFS") or time to progression versus
standard of

20

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care) such that it would be reasonable in the opinion of a Party (the "Proposing
Party") to continue to the corresponding Specified Phase III Study (with any
dispute between the Parties as to whether such specified Signal Finding Study
did produce such positive results to be referred to a scientific advisory board
with three members, one appointed by each of ERS and the Company and the third
appointed by such appointees, for a non-binding recommendation), and, after
proposing such Specified Phase III Study as a Proposed Study in accordance with
the provisions of Section 4.3(e) and, if such Proposed Study is not approved as
an Approved Study and the Proposing Party wishes to fund individually such
Proposed Study as a "Sole-Funded SFI Registrational Study", the Proposing Party
shall give written notice to the other Party (the "Non-Proposing Party") of its
intent to conduct such Proposed Study as a Sole-Funded SFI Registrational Study,
and shall provide to the Non-Proposing Party an updated Clinical Budget for such
Sole-Funded SFI Registrational Study including all the budget information that
would be required by Exhibit 1.20 if such Sole-Funded SFI Registrational Study
were an Approved Study and any information with respect to proposed amendments
or modifications that the Proposing Party proposes to make with respect to such
Proposed Study that were not previously provided to the Non-Proposing Party and
considered when such Specified Phase III Study was proposed as a Proposed Study
but not approved as an Approved Study pursuant to Section 4.3(f). If the
Non-Proposing Party again decides not to approve such Specified Phase III Study
as an Approved Study, then the Proposing Party shall have the right to conduct
such Specified Phase III Study as a Sole-Funded SFI Registrational Study on the
same basis as it had initially proposed to conduct such Proposed Study as
amended or modified by any proposed amendments or modifications disclosed to the
Non-Proposing Party pursuant to the preceding sentence, and subject to the
following terms:

        (A)  The Proposing Party shall pay 100% of the Development Costs related
to such Sole-Funded SFI Registrational Study;

        (B)  Such Sole-Funded SFI Registrational Study shall not be conducted if
in the opinion of the Non-Proposing Party the Sole-Funded SFI Registrational
Study presents a medical risk/benefit that is so unfavorable as to be
incompatible with the welfare or safety of patients.

        (C)  Following commencement of the Sole-Funded SFI Registrational Study,
the Proposing Party shall provide written notice to the Non-Proposing Party of
any proposed amendment or modification to the Sole-Funded SFI Registrational
Study not less than 20 business days prior to making such modification or
amendment. The Proposing Party shall have the right to make such modifications
or amendments to the Sole-Funded SFI Registrational Study, provided that the
Proposing Party first shall have provided the Non-Proposing Party with such
additional information with respect to such proposed amendment or modification
as the Non-Proposing Party shall reasonably request and a reasonable period of
time to review and comment on such proposed amendments or modifications, and
provided further that such proposed amendment or modification shall not be made
if in the opinion of the Non-Proposing Party it presents a medical risk/benefit
that is so unfavorable as to be incompatible with the welfare or safety of
patients.

         (ii)  All Parties shall benefit from any Sole-Funded SFI Registrational
Study to the same extent as if such Sole-Funded SFI Registrational Study had
been jointly funded by the Parties, provided that if such Sole-Funded SFI
Registrational Study results in regulatory approval in the U.S. or Canada of a
line of therapy in a new tumor type for which regulatory approval has not
previously been granted with respect to the Product not later than the date that
is two years prior to the expiration of the Term (the satisfaction of such
conditions resulting in a "Successful Indication" or "SFI"), then, at the

21

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Non-Proposing Party's election (such election to be made by such Non-Proposing
Party within 30 calendar days after the Proposing Party has delivered written
notice to such Non-Proposing Party that such regulatory approval has been
received), either (A) the Proposing Party shall be solely entitled to, and shall
solely bear, the Incremental SFI Profit Or Loss attributable to such Successful
Indication or (B) the Non-Proposing Party shall pay to the Proposing Party an
amount equal to [*] of the lesser of (1) the amount of Development Costs
attributable to such Sole-Funded SFI Registrational Study that the Non-Proposing
Party would have been responsible to fund if such Sole-Funded SFI Registrational
Study had been an Approved Study funded in accordance with the provisions of
Section 4.6 (i.e., based on the Clinical Budget that was presented to the
Non-Proposing Party when it made the final decision not to fund such Sole-Funded
SFI Registrational Study pursuant to Section 4.3(g)(i)) and (2) the amount of
Development Costs attributable to such Sole-Funded SFI Registrational Study that
it would have been responsible to fund in accordance with the provisions of
Section 4.6 based on the Development Costs actually incurred. If the
Non-Proposing Party elects clause (A) with respect to any SFI, the Parties shall
work together in good faith to finalize and implement a process for determining
Incremental SFI Profit Or Loss attributable to such Successful Indication,
including a methodology for determining the amount of adjustments to net sales
and costs incurred by each Party and its Affiliates that are attributable to, or
reasonably allocable to, such SFI and a methodology for such allocation and the
mechanics for payments related to Incremental SFI Profit Or Loss and adjustments
to Distribution Fees payable as a result of such election. If such Non-Proposing
Party elects to make the payments in clause (B) above with respect to any SFI,
such payments shall be made by wire transfer in immediately available funds in
equal quarterly installments in advance over a three-year period, the first
payment to made on the first day of the first calendar quarter following receipt
of the applicable FDA approval. For clarity, if such Non-Proposing Party elects
to make the payment referred to in clause (B) with respect to any SFI, then the
Parties shall jointly co-promote such SFI and shall benefit from such SFI in
each case to the same extent as if the Sole-Funded SFI Registrational Study that
resulted in such SFI had been jointly funded by the Parties.

        (iii)  If the Non-Proposing Party shall have elected to allow the
Proposing Party to receive/bear the Incremental SFI Profit Or Loss under
Section 4.3(g)(ii)(A), then the Proposing Party, but not the Non-Proposing
Party, shall:

        (A)  be solely responsible for the sales force detailing, marketing and
medical education activities for such SFI, provided that ERS shall retain the
right to book all sales and determine the terms and conditions of sale
(including pricing and managed care contracting strategies) and amount and terms
of any adjustments to net sales;

        (B)  be solely responsible for all Marketing Costs, medical education
activity costs, regulatory costs, Sales Costs and other costs incurred by either
Party or any of its respective Affiliates that are attributable to or reasonably
allocable to such SFI;

        (C)  be solely entitled to develop the Marketing Plan and Marketing
Budget for such SFI, provided that such Marketing Plan for such SFI be reviewed
by the JCC and the JCC shall have determined it to be consistent in all key
respects (including product positioning) with the Marketing Plan approved by the
JCC for all other indications for the Product that ERS and the Company are
co-promoting;

--------------------------------------------------------------------------------

*Omitted and filed separately pursuant to a request for confidential treatment
submitted to the Securities and Exchange Commission.

22

--------------------------------------------------------------------------------

        (D)  be solely entitled to, and shall solely bear, the entire
Incremental SFI Profit Or Loss that is attributable to such SFI.

If the Proposing Party is the Company, then ERS shall pay to the Company such
Incremental Profit, and the Company shall pay to ERS for any Incremental Loss,
attributable to such SFI, in each case on a quarterly basis. If the Proposing
Party is ERS, then ERS shall be entitled to such Incremental SFI Profit, and
shall bear any Incremental SFI Loss, attributable to such SFI, but shall
reimburse the Company for any costs incurred by the Company or any of its
Affiliates that are included in the determination of Incremental SFI Profit Or
Loss on a quarterly basis. All payments pursuant to this
Section 4.3(g)(iii) shall be made by wire transfer in immediately available
funds not later than seventy-five days after the end of the applicable calendar
quarter in which there is any amount of Incremental SFI Profit Or Loss for such
SFI. If the Proposing Party and the Non-Proposing Party cannot agree on the
determination of any matter pertaining to the calculation of Incremental SFI
Profit Or Loss attributable to such SFI for a given accounting period, including
the determination of any amounts to be taken into account in the determination
of such Incremental SFI Profit Or Loss for such SFI, then either Party may
submit such dispute to arbitration pursuant to Section 16.13.

        (iv)  Each Proposing Party shall be solely responsible for, and hereby
assumes, any and all risks of personal injury or property damage attributable to
the acts or omissions of such Proposing Party and/or any of its Affiliates, and
their respective directors, officers, employees, agents and independent
contractors (e.g., CROs) for each Sole-Funded SFI Registrational Study conducted
by such Proposing Party. Each Proposing Party shall indemnify, defend, and hold
harmless the Non-Proposing Party and its Affiliates, and their respective
directors, officers, employees, agents and independent contractors (e.g., CROs)
from and against any and all liabilities, damages, losses, costs and expenses
(including the reasonable fees of attorneys and other professionals) to the
extent arising out of claims, actions, suits or proceedings that may be brought,
in each case that are attributable to or arise out of the (A) acts or omissions
of such Proposing Party or its Affiliates, and their respective directors,
officers, employees, agents and independent contractors (e.g. CROs), in
connection with each Sole-Funded SFI Registrational Study conducted by such
Proposing Party or (B) with respect to each SFI for which such Party is the
Proposing Party and the Non-Proposing Party shall have elected to allow the
Proposing Party to receive/bear the Incremental SFI Profit Or Loss under
Section 4.3(g)(ii)(A) for such SFI, the development, marketing, sale, use or
commercialization of the Product for such SFI. Nothing in this
Section 4.3(g)(iv) shall limit the indemnification obligations of any Party in
Section 12.2 and 12.3. The provisions of Sections 12.4 and 12.5 with respect to
claims for indemnification shall be applicable to any claim for indemnification
pursuant to this Section 4.3(g)(iv).

        (h)   (i) In order for a Contingent Approved Study to become an Approved
Study, (A) the PDC must review and unanimously recommend to the JEC whether a
Contingent Approved Study has satisfied each of the Contingencies related to
such Contingent Approved Study and shall become an Approved Study and (B) the
JEC must review and unanimously approve that such Contingencies related to the
Contingent Approved Study have been satisfied, all in accordance with the
provisions of Sections 2.1(b)(iv) and 2.3(b)(iii). The Party designated as the
Responsible Party for such Contingent Approved Study shall provide to the other
Party written evidence of the satisfaction of such Contingencies. Any increase
in the Clinical Budget or other proposed change in the Contingent Approved Study
shall be subject to agreement by the parties pursuant to Sections 2.3(b)(v) and,
if applicable, 2.1(b)(v). When it has been unanimously determined by the JEC
that each of the Contingencies applicable to a Contingent

23

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Approved Study has been satisfied, such Contingent Approved Study shall be
designated as an Approved Study in the then-current Clinical Development Plan.
If upon the unanimous recommendation of the PDC, the JEC unanimously determines
that one or more of the Contingencies for a particular Contingent Approved Study
has failed to be satisfied, such Contingent Approved Study shall be removed from
the Clinical Development Plan. If it is determined that one or more of the
Contingencies applicable to any Contingent Approved Study has failed to be
satisfied, either Party may propose that further work should be supported in the
tumor type that was the subject of such Contingent Approved Study and that such
study should be continued with or without modification, in which event such
further work would be proposed as a Proposed Study and be subject to the
provisions of Sections 4.3(e) and 4.3(g). Notwithstanding the foregoing, a
Contingent Approved Study shall not become an Approved Study nor shall any such
further work be conducted if in the opinion of either Party the Contingent
Approved Study presented a medical risk/benefit that is so unfavorable as to be
incompatible with the welfare and safety of patients.

         (ii)  If the Contingent Approved Study did not specify the Responsible
Party when such Contingent Approved Study was initially included in a Clinical
Development Plan, the Parties shall determine the Responsible Party within sixty
days after the determination that a Contingent Study has become an Approved
Study, and no Party shall unreasonably withhold its consent to such
determination. If the Contingent Approved Study did not specify whether a CRO
would be used to conduct such Contingent Approved Study when it was initially
included in the Clinical Development Plan, such determination shall be made in
accordance with the provisions of Section 4.5(a). Following the later to occur
of determination that a Contingent Approved Study shall have become an Approved
Study and the determination of the Responsible Party for such Approved Study,
the Responsible Party will be responsible for and prepare the protocol for such
Approved Study and an updated Clinical Budget for such Approved Study. In order
for the proposed protocol for such Approved Study and the related updated
Clinical Budget to be finalized, (1) the PDC must review and unanimously
recommend such proposed protocol and related updated Clinical Budget to the JEC
for approval, and (2) the JEC must unanimously approve such proposed protocols
and related updated Clinical Budgets, all in accordance with the provisions of
Sections 2.1(b)(iv) and 2.3(b)(iii).

        (i)    At any time prior to the expiration of the Agreement, each of ERS
and the Company may propose to add an Emergency Study to the then-current
Clinical Development Plan by providing written notice to the other Party,
including a reasonably detailed description of the reasons why the proposing
Party believes such Emergency Study needs to be conducted together with the
information required by Exhibit 1.20 related to such Emergency Study, including
a Clinical Budget. The Party seeking to add such Emergency Study also shall
promptly provide the other Party such additional information with respect to the
Emergency Study as the other Party shall reasonably request. In order for an
Emergency Study to become an Approved Study, (1) the PDC must review and
unanimously recommend such Emergency Study to the JEC for approval, and (2) the
JEC must unanimously approve such Emergency Study, all in accordance with
Section 2.1(b)(iii) and 2.3(b)(ii) and subject to the provisions of
Section 2.1(d)(v)(B).

        (j)    Prior to Registration in any country in the Territory, the
Parties intend that the Company will be primarily responsible for implementing
the regulatory strategy for the Products in such country developed by the PDC.
The Parties intend that ERS will be primarily responsible for regulatory
activities in a country in the Territory after Registration in such country,
comprising regulatory compliance, worldwide safety surveillance, adverse event
reporting and all other necessary support services."

24

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        SECTION 4.    Amendment to Section 4.5 of the
Agreement.    (a) Section 4.5(a) is hereby deleted in its entirety and replaced
with the following:

        "(a) (i) Each of ERS and the Company shall be responsible for the
preparation of all protocols and the conduct of all Approved Studies and
Contingent Approved Studies for which such Party is designated as the
Responsible Party. Each such Party shall submit all protocols therefor to the
PDC and the JEC for approval in accordance with the provisions of Sections
4.3(f) and 4.3(h)(ii), as applicable.

         (ii)  If either the Responsible Party or the other Party desires to
solicit bids to have such Approved Study or Contingent Study or a Proposed Study
conducted by a CRO, the Parties shall solicit bids from CROs that are reasonably
satisfactory to both Parties and that have sufficient capabilities and
resources. In the case of any Approved Study included in Exhibit A of the
2007-2009 Clinical Development Plan as of the date of this Amendment No. 2 for
which the determination of whether to use a CRO is marked "TBD", the Parties
shall solicit such bids within 60 days after the date of this Amendment No. 2.
In the case of each Proposed Study that would be an Approved Study, such
solicitation and receipt of any final bids shall be completed prior to
completion of the approval process for such Proposed Study contemplated by
Section 4.3(f). In the case of any Contingent Approved Study, the Parties shall
solicit such bids not later than sixty days after such Contingent Approved Study
becomes an Approved Study. [*]"

        (b)   Section 4.5(b) is hereby deleted in its entirety and replaced with
the following:

        "(b) Each of ERS and the Company shall be responsible for preparing all
Regulatory Applications necessary or desirable to register the Products in all
countries in the Territory for which such Party is the Responsible Party. The
Company shall be responsible for filing all Regulatory Applications (whether
prepared by the Company or ERS) and, thereafter, to conduct all communications
with the Regulatory Authorities during the registration process (provided that,
if ERS is the Responsible Party for the preparation of such Regulatory
Application, it will work with the Company with respect to all such regulatory
activities). Each such Party shall submit all proposed filings to the PDC for
its approval. The other such Party shall provide all technical data and support
necessary to assist the Responsible Party to prepare such Regulatory
Applications. The Responsible Party shall keep the PDC informed as to the status
of such efforts, permit the PDC to review any revisions to any filings or
communications with Regulatory Authorities during their preparation, and shall
confer with the PDC regarding the preparation of such filings and communications
and the registration process. During such process, such Parties shall
collaborate and cooperate in the preparation and filing of all documents
necessary therefor and all regulatory interactions and compliance with
Regulatory Authorities in the Territory. All regulatory activities (including
without limitation adverse event reporting) to be performed by ERS in accordance
with this Agreement and the Clinical Development Plan shall be conducted on
behalf of the Company. The Company shall appoint ERS as its agent for regulatory
compliance and all other regulatory activities for which ERS is responsible."

--------------------------------------------------------------------------------

*Omitted and filed separately pursuant to a request for confidential treatment
submitted to the Securities and Exchange Commission.

25

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        (c)   Section 4.5(c) is hereby deleted in its entirety and replaced with
the following:

        "(c) The Company shall supply all API necessary and/or desirable for all
Approved Studies, Contingent Approved Studies and Sole-Funded SFI Registrational
Studies included in any Clinical Development Plan, as well as any studies that a
Party proposes to conduct under Section 4.3(a)(ii)(B) that are not so included.
Such API shall be supplied in accordance with, in all material respects, the
Specifications, in accordance with cGMP, and in accordance with forecasts
therefor provided by the PDC at least 180 days prior to the anticipated delivery
date for each shipment thereof. Such API shall be supplied at the Company's
Fully Burdened Manufacturing Cost without any mark-up. The Company's obligation
to supply API for Phase IV Clinical Trials shall be subject, first, to
fulfilling all requirements for API for the supply of Products for commercial
sales pursuant to Section 8. Except as otherwise provided in this
Section 4.5(c), all of the provisions of Section 8, to the extent applicable,
shall apply to the supply of API for all such Approved Studies, Contingent
Approved Studies, Sole-Funded SFI Registrational Studies or such other studies
conducted under Section 4.3(a)(ii)(B) (including the reference to the relevant
payment terms contained in Section 7)."

        (d)   Section 4.5 of the Agreement is hereby amended by inserting the
following two paragraphs at the end thereof:

        "(e) Within 45 days after the end of each quarter during the term of the
Agreement, commencing with the quarter ended June 30, 2007, each of ERS and the
Company shall provide the other Party a quarterly analysis of actual spend
versus budgeted and projected spend with respect to the Development Costs
relating to the Approved Studies and Contingent Approved Studies for which ERS
or the Company, as applicable, is designated as the Responsible Party.

        (f)    Each of ERS and the Company shall provide the other Party with
immediate notice for any proposed change or proposed amendment or modification
that constitutes a Material Modification."

        SECTION 5.    Amendment to Section 4.6 of the Agreement.    Section 4.6
of the Agreement is hereby deleted in its entirety and replaced with the
following:

        "4.6 Funding of Clinical Development Plans.

        (a)   Except as provided in Section 4.6(c), Development Costs related to
North America that are incurred with respect to Approved Studies and Contingent
Approved Studies included in the 2007-2009 Clinical Development Plan for the
period commencing on and including January 1, 2007 and ending on and including
December 31, 2009, shall be funded by ERS and the Company as follows:

          (i)  ERS will fund (A) [*] of (1) the first [*] of such Development
Costs incurred in 2007, (2) the first [*] of such Development Costs incurred in
2008 and (3) the first [*] of such Development Costs incurred in 2009 and
(B) [*] of such Development Costs incurred in excess of (1) [*] in 2007, (2) [*]
in 2008 and (3) [*] in 2009; and

--------------------------------------------------------------------------------

*Omitted and filed separately pursuant to a request for confidential treatment
submitted to the Securities and Exchange Commission.

26

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         (ii)  the Company will fund [*] of such Development Costs incurred in
excess of (1) [*] in 2007, (2) [*] in 2008 and (3) [*] in 2009.

Notwithstanding the foregoing, ERS and the Company have agreed that for the
Approved Study designated as [*], ERS has agreed to fund [*] of the drug costs
for [*] and the Company has agreed to fund [*] of the drug costs for [*], and
that (x) ERS's [*] share of such costs shall be included in determining whether
ERS satisfied its funding requirements pursuant to Section 4.6(a)(i)(A) and
(y) the Company's [*] share of such costs shall be payable even if ERS shall not
have satisfied its full funding requirements pursuant to Section 4.6(a)(i)(A)
expended by ERS related to [*].

        (b)   Except as provided in Section 4.6(c), Development Costs related to
North America that are incurred with respect to Approved Studies and Contingent
Approved Studies included in any Clinical Development Plan in each calendar year
thereafter, commencing with and including 2010, will be funded [*] by BMS and
[*] by the Company.

        (c)   Any monies received from any Third Party, including any Merck
Entity, to fund any Development Costs related to North America that are incurred
in any calendar year shall be applied to reduce each Party's obligations to fund
Development Costs for such calendar year as follows:

          (i)  in calendar years 2007, 2008 and 2009, such monies shall be
applied first to reduce the Parties' obligations to fund such Development Costs
in excess of [*] in 2007, [*] in 2008 and [*] in 2009, with [*] of such monies
allocated to such Development Costs for which ERS is responsible pursuant to
Section 4.6(a)(i)(B) and [*] of such monies allocated to such Development Costs
for which the Company is responsible pursuant to Section 4.6(a)(ii), and
thereafter to reduce ERS's obligation to fund the first [*], as applicable, of
such Development Costs for which BMS is responsible pursuant to
Section 4.6(a)(i)(A), and

--------------------------------------------------------------------------------

*Omitted and filed separately pursuant to a request for confidential treatment
submitted to the Securities and Exchange Commission.

27

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         (ii)  in each calendar year thereafter, commencing with and including
2010, [*] of such monies shall be applied to reduce the Development Costs for
which ERS is responsible pursuant to Section 4.6(b) and [*] of such monies shall
be applied to reduce the Development Costs for which the Company is responsible
pursuant to Section 4.6(b).

        (d)   Notwithstanding anything to the contrary in this Section 4.6, any
portion of ERS's 2007 [*] funding obligation under Section 4.6(a)(i)(A)(1) that
is not used to fund Development Costs in 2007 shall be carried over to 2008 (but
not beyond 2008) and shall increase on a dollar-for-dollar basis the amount of
Development Costs that ERS would otherwise be obligated to fund in 2008 under
Section 4.6(a)(i)(A)(2), provided that the amount that may be carried over shall
be limited to [*].

        (e)   Notwithstanding anything to the contrary in this Section 4.6, from
and after January 1, 2007, all Medical Science Liaison costs reasonably
allocable to the Product incurred by each of ERS and the Company shall be [*].

        (f)    Notwithstanding anything to the contrary set forth in this
Agreement, if the actual Development Costs related to North America for any
Approved Study or Contingent Approved Study are less than the budgeted expenses
for such Approved Study or Contingent Approved Study in any calendar year or in
the aggregate, neither Party shall be required to fund any amount in excess of
such actual Development Costs incurred or to allocate such excess amount to any
other Approved Study, Contingent Approved Study, Proposed Study or any other
study.

        (g)   The funding requirements and responsibilities for Development
Costs related to Japan shall be as set forth in the Japan Co-Commercialization
Agreements." For clarity, Development Costs incurred by any Party in connection
with the Japan Co-Commercialization Agreements are not subject to the provisions
of Sections 4.6(a), (b), (c), (d), (e) and (f)."

--------------------------------------------------------------------------------

*Omitted and filed separately pursuant to a request for confidential treatment
submitted to the Securities and Exchange Commission.

28

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        SECTION 6.    Amendment to Section 4.10 of the
Agreement.    Section 4.10 of the Agreement is hereby deleted in its entirety
and replaced with the following:

        "4.10    Liability.    Each Party shall be responsible for, and hereby
assumes, any and all risks of personal injury or property damage attributable to
the negligent or willful acts or omissions of such Party or its Affiliates, and
their respective directors, officers, employees and agents and for the Approved
Studies, Contingent Approved Studies and studies conducted by such Party under
Section 4.3(a)(ii)(B) that the Party is responsible for conducting and the other
responsibilities of such Party pursuant to this Section 4."

        SECTION 7.    Amendment to Section 6 of the
Agreement.    (a) Section 6.3 is hereby deleted in its entirety and replaced
with the following:

        "6.3    Distribution Fees for North America.    As further consideration
to the Company for the rights granted to ERS in North America under this
Agreement, ERS shall pay to the Company a Distribution Fee for North America
equal to 39% of Net Sales in North America during each calendar year (or portion
thereof), provided that if, pursuant to Section 4.3(g)(ii), a Proposing Party
shall be solely entitled to, and shall solely bear, the entire Incremental SFI
Profit Or Loss, then all Net Sales in North America that are attributable to
such Successful Indication shall be excluded from Net Sales for the purpose of
this Section 6.3."

        (b)   Section 6 is hereby amended by inserting at the end the following
Section:

        "6.6    Settlement of Funding of Development Costs Incurred Prior to
2007.    (a) The Parties agree that ERS has satisfied all its funding
obligations with respect to Development Costs for the period through and
including December 31, 2006. The Parties further agree that Company's previously
agreed obligation of [*] to fund certain Development Costs for 2005 and 2006 is
immediately due and payable. Such payment shall be made by the Company to ERS by
wire transfer in immediately available funds within three business days of the
execution of this Amendment No. 2. The Parties acknowledge and agree that such
amount has been calculated based on a retrospective increase in the
Registrational Study (as defined by the Agreement prior to this Amendment No. 2)
spend included in Amendment No. 1 by [*], from [*] to [*] in the aggregate and
an allocation of that increase as follows: [*] to 2005 and [*] to 2006.

--------------------------------------------------------------------------------

*Omitted and filed separately pursuant to a request for confidential treatment
submitted to the Securities and Exchange Commission.

29

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        (b)   The Company shall pay to ERS [*] representing the Company's share
of Medical Science Liaisons expenses incurred by ERS in respect of the Product
for the period through December 31, 2006. Such payment shall be made by the
Company to ERS by wire transfer in immediately available funds within three
business days of the execution of this Amendment No. 2.

        (c)   Upon payment of the amounts in Sections 6.6(a) and 6.6(b), the
Parties agree that the Company will have satisfied its obligations with respect
to Development Costs for the period through and including December 31, 2006."

        SECTION 8.    Amendments to Section 7 of the
Agreement.    (a) Section 7.2 is hereby deleted in its entirety and replaced
with the following:

        "7.2    Reports.    (a) Beginning with the month in which the First
Commercial Sale is made in the Territory and for each month thereafter, (i) ERS
shall submit on the fifth business day following the close of such month (closed
in accordance with ERS's then standard practices), a net sales report regarding
such month's Net Sales in the United States; (ii) ERS shall submit on the
twentieth business day following the close of such month (closed in accordance
with ERS's then standard practices), a net sales report regarding such month's
Net Sales in Canada; (iii) each of ERS and the Company shall submit to the other
on the twentieth business day following the close of such month (closed in
accordance with such Party's own then standard practices), an expense report
separately detailing, for such month, such Party's Development Costs for
Approved Studies, Contingent Approved Studies and Sole-Funded SFI Registrational
Studies in each of North America and Japan, and Operating Profit and Loss
detailed and broken down into its constituent components in accordance with the
Financial Appendix.

        (b)   For each SFI for which a Non-Proposing Party shall have elected to
allow the Proposing Party to receive/bear the Incremental SFI Profit Or Loss
under Section 4.3(g)(ii)(A), beginning with the calendar quarter in which the
First Commercial Sale of Product for such SFI is made in the Territory and for
each calendar quarter thereafter, within sixty days after the end of such
calendar quarter, (i) ERS shall submit a net sales report regarding such
quarter's Net Sales in the U.S. of Products that are attributable to each
Successful Indication ("SFI Net U.S. Sales") and such quarter's Net Sales in
Canada of Products that are attributable to each Successful Indication ("SFI Net
Canadian Sales") and (ii) such Non-Proposing Party shall submit to the Proposing
Party, an expense report detailing all costs incurred by such other Party and
its Affiliates attributable to or reasonably allocable to such SFI
("Attributable Other Party SFI Expenses") with respect to such quarter.

--------------------------------------------------------------------------------

*Omitted and filed separately pursuant to a request for confidential treatment
submitted to the Securities and Exchange Commission.

30

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        (c)   Such reports are to be made in support of the payments to be made
pursuant to this Agreement and in accordance with the Financial Appendix. For
the avoidance of doubt, the Parties shall also fulfill any additional reporting
requirements, if any, set forth elsewhere in this Agreement."

        (b)   Section 7.4 is hereby deleted in its entirety and replaced with
the following:

        "7.4    Records Retention.    ERS, the Company and each such Party's
respective Affiliates shall keep complete and accurate records pertaining to the
sale of Products and the Product-by-Product and Product-consolidated calculation
of Net Sales in North America, Net Sales in Japan and Operating Profit or Loss
in Japan and, for each SFI, SFI Net U.S. Sales, SFI Net Canadian Sales, and
Attributable Other Party SFI Expenses, for each calendar quarter, including
without limitation the determination of Fully Burdened Manufacturing Cost of API
and of Finished Product, Development Costs, Distribution Costs, Sales Costs,
Marketing Costs, General and Administrative Costs and Other Operating
Income/Expense for a period of three calendar years after the year in which such
sales or costs occurred, and in sufficient detail to permit the Company to
confirm the accuracy of each of the foregoing and of the aggregate Distribution
Fees provided by ERS under this Agreement."

        (c)   Section 7.5 is hereby deleted in its entirety and replaced with
the following:

        "7.5    Audit Request.    During the term of this Agreement and for a
period of three years thereafter, at the request and expense of any Party (the
"Auditing Party"), the Company (in the case of a request by BMS or ERS) or ERS
and BMS (in the case of a request by the Company), (the "Audited Party"), and
its Affiliates shall permit an independent, certified public accountant
appointed by the Auditing Party and reasonably acceptable to the Audited Party,
at reasonable times and upon reasonable notice but not more often than two times
each calendar year, to examine such records as may be necessary to determine the
correctness of any report or payment made under this Agreement, to determine the
consistency of actual expenditures versus the budgeted expenditures set forth in
the Clinical Budget and/or any Marketing Budget, as the case may be, or obtain
information as to the determination of Fully Burdened Manufacturing Cost of API
(including, without limitation, the records of when during API production API
batches failed, the cost and nature of such failures), the determination of
Fully Burdened Manufacturing Cost of processing API into Finished Product and
the aggregate Net Sales, Operating Profit or Loss and Distribution Fees payable
for any calendar month, including without limitation, Development Costs,
Distribution Costs, Sales Costs, Marketing Costs, General and Administrative
Costs and Other Operating Income/Expense and, for each SFI, SFI Net U.S. Sales,
SFI Net Canadian Sales and Attributable Other Party SFI Expenses, for each
calendar quarter. Results of any such examination shall be made available to all
Parties except that said independent, certified public accountant shall verify
to the Auditing Party such amounts and shall disclose no other information
revealed in such audit."

31

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        SECTION 9.    Amendment to Section 8.6 of the
Agreement.    (a) Section 8.6(a) of the Agreement is hereby deleted in its
entirety and replaced with the following:

        "(a) The purchase price for all API supplied by the Company to ERS
pursuant to this Section 8 for commercial use in North America shall be the
Company's Fully Burdened Manufacturing Cost for such API plus a mark-up of 10%;
provided that process development, process improvement, scale up, recovery, and
qualification lots costs (although components of Fully Burdened Manufacturing
Cost) shall not be subject to the mark up of 10%. Commencing with the
implementation of the ERBITUX PAP (as such term is defined in the Side Letter),
the purchase price for all API supplied by the Company to ERS for use in the
ERBITUX PAP shall be [*] of the Company's Fully Burdened Manufacturing Cost for
such API, provided that in each calendar year, commencing with and including
2007, once the aggregate purchase price paid by ERS for such API supplied by the
Company to ERS during such year is [*] (i.e., the equivalent of [*] of
Fully-Burdened Manufacturing Costs in the aggregate for the API so purchased by
ERS), the purchase price for any additional API supplied by the Company to ERS
for use in the ERBITUX PAP during such calendar year shall be [*] of Fully
Burdened Manufacturing Cost. Within 45 calendar days after the end of the first
calendar quarter after the ERBITUX PAP has been implemented and each calendar
quarter thereafter, ERS shall provide written notice to the Company setting
forth (i) the amount of Products distributed pursuant to the ERBITUX PAP in such
calendar quarter and (ii) a calculation of the amount of the discount to the
purchase price owed to ERS with respect to such Products, representing the
difference between the purchase price actually paid for such Products and the
price payable for such Products pursuant to the above provision in this
Section 8.6(a). Such discount to the purchase price shall be paid by the Company
to ERS by wire transfer in immediately available funds within five business days
of receipt of each such written notice."

--------------------------------------------------------------------------------

*Omitted and filed separately pursuant to a request for confidential treatment
submitted to the Securities and Exchange Commission.

32

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        (b)   Section 8.6(c) of the Agreement is hereby deleted in its entirety
and replaced with the following:

        "(c) For API supplied to ERS for Approved Studies, Contingent Approved
Studies, Sole-Funded SFI Registrational Studies or other studies conducted under
Section 4.3(a)(ii)(B) and for commercial use in North America, the Company shall
submit invoices to ERS for API promptly after shipment. Payments shall be made
by ERS within 60 days after ERS's receipt of the invoice. ERS has no obligation
to pay for any shipment of API that (i) ERS and the Company agree does not to
meet the Specifications and/or Manufacturing Standards, or (ii) in accordance
with Section 8.8(b), ERS has found not to meet the Specifications and/or
Manufacturing Standards while such findings have not been contradicted by
independent laboratory testing. Upon the Company's receipt of a notice from ERS
claiming that a shipment of API does not meet the Specifications and/or
applicable Manufacturing Standards, the time period for payment of such shipment
or such batch shall toll until such time as such non-conformity questions
regarding such shipment or such batch are resolved in accordance with
Section 8.8. All relevant terms of Section 7 with respect to payments of
Distribution Fees shall apply to the payment of invoices for the supply of API."

        (c)   Section 8.6(d) of the Agreement is hereby deleted in its entirety
and replaced with the following:

        "(d) The Parties, through the co-chairs of the JMC, will work together
to agree on a specific plan of action under which the Company will reduce the
Fully Burdened Manufacturing Cost of manufacturing API itself to an amount equal
to or less than [*] with a goal of finalizing such plan by September 30, 2007,
and implementing such plan as soon as practicable thereafter. Until such time
that the Company achieves such reduction in Fully Burdened Manufacturing Cost to
[*] or less, any excess in the Fully Burdened Manufacturing Cost above [*] will
be borne equally by ERS and the Company.

--------------------------------------------------------------------------------

*Omitted and filed separately pursuant to a request for confidential treatment
submitted to the Securities and Exchange Commission.

33

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        (e)   It is the intention of the Parties that the Company will maintain
a rolling eight-week supply of finished, packaged Product that has been quality
assurance-released by the Company and received by ERS. The Parties, through the
co-chairs of the JMC, will work together to agree on a specific plan of action
under which the Company will maintain such supply, with a goal of finalizing
such plan by September 30, 2007, and implementing such plan as soon as
practicable thereafter. Following such implementation, the Company shall provide
written notice to ERS promptly, and in any event within five business days, if
at any time the supply of finished, packaged Product that has been quality
assurance-released by the Company and received by ERS shall be less than a
five-week supply. In such event, the Parties, through the co-chairs of the JMC,
shall work together promptly to develop a specific plan of action to replenish
such supply to an eight-week supply as contemplated by this Section 8.6(e). For
purposes of this Section 8.6(e), weeks supply of finished, packaged Product by
SKU shall be calculated based on the then current firm order placed by ERS
pursuant to Section 8.4 of this Agreement."

        SECTION 10.    Amendment to Section 8.12 of the
Agreement.    Paragraph (b) of Section 8.12(b) of the Agreement is hereby
deleted in its entirety and replaced with the following:

        "(b) An "Inability to Supply" shall mean: (i) with respect to the supply
of API for Approved Studies, Contingent Approved Studies or Sole-Funded SFI
Registrational Studies, the Company's failure for any reason, including without
limitation force majeure reasons or otherwise, to supply ERS with quantities of
API meeting the Specifications and Manufacturing Standards equal to at least [*]
of the quantity of API required to conduct such Approved Study, Contingent
Approved Study or Sole-Funded SFI Registrational Study, as the case may be,
during the applicable time period; and (ii) with respect to the supply of API
for commercial sales, the Company's failure for any reason, including without
limitation force majeure reasons or otherwise, to supply ERS with quantities of
API meeting the Specifications and Manufacturing Standards equal to at least [*]
of the quantity of API required for commercial sales during the applicable time
period."

--------------------------------------------------------------------------------

*Omitted and filed separately pursuant to a request for confidential treatment
submitted to the Securities and Exchange Commission.

34

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        SECTION 11.    Amendments to Section 12 of the
Agreement.    (a) Section 12.1 is hereby deleted in its entirety and replaced
with the following:

"Investigation; Recall.    In the event that the Regulatory Authority in any
country in the Territory shall allege or prove that a Product does not comply
with applicable rules and regulations in such country, ERS shall notify the
Company immediately. The JEC, with assistance from the PDC, the JCC or the JMC,
as the JEC determines is appropriate, shall conduct any appropriate
investigation and shall make a determination as to the disposition of any such
matter. If ERS is required or if the JEC should deem it appropriate to recall
any Product, the Company and ERS shall bear the costs and expenses associated
with such recall, in North America in the proportion of 39% for the Company and
61% for ERS, and in Japan in the proportion for which such Party is entitled to
receive Operating Profit or Loss, as the case may be, unless: (i) the
predominant cause of such recall results from or also constitutes the Company's
breach of its representation and/or warranty set forth in Section 11.2(e) and/or
ERS's reliance upon such breached representation and/or warranty, or unless the
predominant cause of such recall results from the Company's willful wrongdoing
or negligence, in each such case the Company shall bear all costs and expenses
associated with such recall; or (ii) the predominant cause of such recall
results from ERS's willful wrongdoing or negligence, in which case ERS shall
bear all costs and expenses associated with such recall."

        (b)   Section 12.2 is hereby deleted in its entirety and replaced with
the following:

"Indemnification by ERS and BMS.    ERS and BMS shall indemnify, defend and hold
harmless the Company and its Affiliates, and their respective directors,
officers, employees and agents, from and against any and all liabilities,
damages, losses, costs and expenses (including the reasonable fees of attorneys
and other professionals) to the extent arising out of or resulting from:

        (a)   negligence, recklessness or wrongful intentional acts or omissions
of ERS or its Affiliates, and their respective directors, officers, employees
and agents, in connection with the work performed by ERS or BMS under the
Clinical Development Plans (other than with respect to any Sole-Funded SFI
Registrational Study for which ERS or BMS is the Responsible Party, for which
indemnification is provided in Section 4.3(g)(iv)) or the fulfillment of ERS's
or BMS's obligations under the Marketing Plans;

        (b)   any manufacture, use, distribution or sale of the Products by ERS
or its Affiliates or due to any negligence, recklessness, or wrongful
intentional acts or omissions by or strict liability of, ERS or its Affiliates
and their respective directors, officers, employees and agents.; or

        (c)   any breach of any representation or warranty made by ERS or BMS
under Sections 11.1, 11.3 or 11.4.

Nothing in this Section 12.2 shall limit or restrict the indemnification
obligations of ERS and BMS in Section 4.3(g)(iv)."

        (c)   Section 12.3 is hereby deleted in its entirety and replaced with
the following:

"Indemnification by the Company.    The Company shall indemnify, defend and hold
harmless ERS, BMS and their respective Affiliates, and their respective
directors, officers, employees and agents, from and against any and all
liabilities, damages, losses, costs and expenses (including the reasonable fees
of attorneys and other professionals) to the extent arising out of or resulting
from:

        (a)   negligence, recklessness or wrongful intentional acts or omissions
of the Company or its Affiliates, and their respective directors, officers,
employees and agents, in connection with the Company's fulfillment of its
obligations under the Clinical Development Plans or the fulfillment of the
Company's rights or obligations under the Marketing Plans (other than with
respect to any

35

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Sole-Funded SFI Study for which the Company is the Responsible Party, for which
indemnification is provided in Section 4.3(g)(iv));

        (b)   failure of API to meet the Specifications and/or applicable
Manufacturing Standards or use of Products or promotion of Products not in
conformity with Product labeling, by the Company or its Affiliates, or due to
any negligence, recklessness or wrongful intentional acts or omissions by, or
strict liability of, the Company or its Affiliates, and their respective
directors, officers, employees and agents; or

        (c)   any breach of any representation or warranty made by the Company
under Section 11.1 or 11.2.

Nothing in this Section 12.3 shall limit or restrict the indemnification
obligations of ERS and BMS in Section 4.3(g)(iv)."

        SECTION 12.    Amendment to Section 16.7 of the
Agreement.    Section 16.7 of the Agreement is hereby deleted in its entirety
and replaced with the following:

        "16.7    Public Announcements.    Except as permitted by Section 10.4,
none of the Parties shall make any public announcement concerning this Agreement
or the subject matter hereof without first consulting with the other Parties and
providing such Party with a reasonable opportunity to comment on such proposed
public announcement. In addition, in connection with any public announcement of
results arising from the clinical development of any Product, it shall be the
responsibility of the Party proposing to make such public announcement to comply
with any rules of the organizer of any scientific congress at which such results
are to be presented related to the disclosure of such data so as to ensure that
such data may be presented at such scientific congress, including without
limitation by obtaining the review and, if required, consent of such organizer
of such scientific congress before such Party makes any public announcement of
such results (or any summary thereof), in whole or in part, that will precede
such congress presentation. In the event of a proposed public announcement of
results by both ERS and the Company, they shall designate one Party to be
responsible for complying with the preceding sentence. Nothing in this Section
shall be construed as limiting or hindering any Party's efforts to comply with
applicable laws and regulations regarding such Party's obligation to disclose
material information."

        SECTION 13.    Amendment to Section 16.9 of the
Agreement.    Section 16.9 of the Agreement is hereby amended by inserting at
the end the following sentence:

"No Party shall have any obligation to breach applicable laws, rules and
regulations in performing its obligations under this Agreement."

        SECTION 14.    Amendment to Amendment No. 1.    Amendment No. 1 is
hereby amended by deleting in its entirety Sections 2 and 3.1 of Amendment
No. 1.

        SECTION 15.    Effectiveness; Amendments; Counterparts.    This
Amendment No. 2 shall become effective upon the last to occur of: (i) ERS having
received payment of all amounts due under Section 6.6, (ii) the Parties having
executed the Release and Waiver, (iii) all the parties thereto having executed
the Letter of Intent Regarding the Japan Co-Commercialization Agreements and
(iv) the Parties having executed the Side Letter. No amendment, modification or
supplement of any provisions of this Amendment No. 2 shall be valid or effective
unless made in writing and signed by a duly authorized officer of each Party.
This Agreement may be executed simultaneously in any number of counterparts, any
one of which need not contain the signature of more than one Party but all such
counterparts taken together shall constitute one and the same agreement.

36

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        SECTION 16.    Representations and Warranties.    Each Party represents
and warrants to each of the other Parties, as of the date of this Amendment
No. 2, that:

        (a)   such Party is duly organized, validly existing and in good
standing under the laws of the jurisdiction of its incorporation and has full
corporate power and authority to enter into this Amendment No. 2 and to carry
out the provisions hereof;

        (b)   such Party has taken all corporate action necessary to authorize
the execution and delivery of this Amendment No. 2 and the performance of its
obligations under this Amendment No. 2; and

        (c)   this Amendment No. 2 has been duly executed by such Party and
constitutes a valid and legally binding obligation of such Party, enforceable in
accordance with its terms.

        SECTION 17.    Rights.    Except as specifically set forth herein, the
Agreement shall remain unchanged and in full force and effect. The Parties
acknowledge and agree that there are no amendments, modifications or waivers in
respect of the Agreement other than those specifically set forth in this
Amendment No. 2.

        SECTION 18.    Confidentiality.    The Parties hereby agree that, unless
required by law, they, their Affiliates and their respective employees,
officers, directors and other representatives shall not publish or otherwise
disclose the contents of, or make any other public disclosure with respect to
(including any disclosure with respect to the background of and negotiations
leading up to), this Amendment No. 2 and its Schedules, Exhibits and Annexes,
the Side Letter, the Letter of Intent Regarding the Japanese
Co-Commercialization Agreements and the Release and Waiver. The Parties will
work together to identify the provisions of Amendment No. 2 (including its
Schedules, Exhibits and Annexes) for which they will seek confidential
treatment, pursuant to Rule 24b-2 of the Securities Exchange Act of 1934 and
will use commercially reasonable efforts to seek such confidential treatment.
Following the execution of this Amendment No. 2, the Side Letter, the Letter of
Intent Regarding the Japanese Co-Commercialization Agreements and the Release
and Waiver, each of the Parties may (x) issue a press release in the form
attached hereto as Exhibit 19(A), (y) file a Form 8-K referencing such press
release and (z) file this Amendment No. 2 as an exhibit to a Form 10-Q.

        SECTION 19.    APPLICABLE LAW.    THIS AMENDMENT NO. 2 SHALL BE GOVERNED
BY AND INTERPRETED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK WITHOUT
REGARD TO CONFLICTS OF LAW PRINCIPLES.

        SECTION 20.    Headings.    The descriptive headings of this Amendment
No. 2 are for convenience only, and shall be of no force or effect in construing
or interpreting any of the provisions of this Amendment No. 2.

        SECTION 21.    Entire Agreement.    The Agreement (for clarity, as
amended by this Amendment No. 2), the Letter of Intent Regarding the Japan
Co-Commercialization Agreements, the Side Letter and the Release and Waiver
constitute the entire agreement among the Parties with respect to the subject
matter of this Amendment No. 2 and supersede all prior agreements and
understandings, both oral and written, among the Parties with respect to the
subject matter of this Agreement.

37

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        IN WITNESS WHEREOF, the Parties have caused this Amendment No. 2 to be
duly executed by their respective authorized officers as of the day and year
first written above.

    BRISTOL-MYERS SQUIBB COMPANY,
 
 
By:
 
 
 
          /s/ James M. Cornelius

--------------------------------------------------------------------------------

        Name:   James M. Cornelius         Title:   Chief Executive Officer
 
 
IMCLONE SYSTEMS INCORPORATED,
 
 
By:
 
 
 
          /s/ Alexander J. Denner

--------------------------------------------------------------------------------

        Name:   Alexander J. Denner, Ph.D.         Title:   Chair, Executive
Committee
 
 
E.R. SQUIBB & SONS, LLC,
 
 
By:
 
 
 
          /s/ Sandra Leung

--------------------------------------------------------------------------------

        Name:   Sandra Leung         Title:   Vice President & Secretary

38

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Information to be provided in a Clinical Development Plan

EXHIBIT 1.20

Tumor type:     Indication:     Phase of study:     Type of study   [Approved
Study], [Contingent Approved Study] or [Sole-Funded SFI Registrational Study].
Name of study:     Study design:     No. of patients:     Study endpoint:    
Objective of study/deliverables:     Study start date:     Study end date:    
Status/file date:     Contingencies (go/no-go criteria):     Responsible Party:
    Responsibility for funding:     Clinical Budget Information (Approved
Studies and Contingent Approved Studies only)     Budgeted Aggregate Development
Costs through completion:     Budgeted Annual Development Costs:       [Year
1](1):       [Year 2]:       [Year 3]:     Estimated Annual Development Costs
through completion:       [Year 4]:       [Year 5]:       [additional years as
necessary]:     Budgeted grant costs (and other third-party costs including CRO
costs):       [Year 1]:       [Year 2]:       [Year 3]:     Budgeted aggregate
costs for clinical supplies through completion:     Budgeted internal FTE costs
through completion:    

--------------------------------------------------------------------------------

(1)Years refers to years of Clinical Development Plan.

39

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SCHEDULE 4.3(g)(i)

Specified Phase III Study(1)

--------------------------------------------------------------------------------

  Corresponding Specified Signal Finding Study

--------------------------------------------------------------------------------

ID 22 [*]   ID 16 [*] ID 23 [*]   ID 19 [*]
ID 20 [*] ID 24 [*]   ID 17 [*]

--------------------------------------------------------------------------------

(1)All ID references are to the studies with ID numbers set forth in Exhibit A
to the Clinical Development Plan as of the date of this Amendment No. 2.

--------------------------------------------------------------------------------

*Omitted and filed separately pursuant to a request for confidential treatment
submitted to the Securities and Exchange Commission.

40

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EXHIBIT 1.20A

2007-2009 CLINICAL DEVELOPMENT PLAN

[*]

--------------------------------------------------------------------------------

*Omitted and filed separately pursuant to a request for confidential treatment
submitted to the Securities and Exchange Commission.

41

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