TENDER
        AND SUPPORT AGREEMENT

       

      This
        TENDER AND SUPPORT AGREEMENT (this “Agreement”),
        dated
        as of October 6, 2008, is entered into by and among the entities listed on
        Schedule I hereto (each, a “Stockholder”)
        and
        Eli Lilly and Company, an Indiana corporation (“Parent”).

       

      WHEREAS,
        contemporaneously with the execution of this Agreement, Parent, Alaska
        Acquisition Corporation, a Delaware corporation (the “Purchaser”),
        and
        ImClone Systems Incorporated, a Delaware corporation (the “Company”),
        are
        entering into an Agreement and Plan of Merger, dated as of the date hereof
        (the
“Merger
        Agreement”),
        providing, among other things, for (i) an offer by the Purchaser (the
“Offer”)
        to
        purchase all of the outstanding shares of common stock, par value $0.001
        per
        share, of the Company (the “Company
        Common Stock”)
        and
        the associated preferred stock purchase rights issued in connection with
        and
        subject to the Rights Agreement, dated as of February 15, 2002 and amended
        on
        May 4, 2006, between the Company and EquiServe Trust Company, N.A., as Rights
        Agent (which rights, together with the shares of the Company Common Stock,
        are
        hereinafter referred to as the “Shares”),
        at a
        price per Share of $70.00 (such amount or any different amount per Share
        that
        may be paid pursuant to the Offer, the “Offer
        Price”)
        and
        (ii) following the acceptance for payment of Shares pursuant to the Offer,
        the
        merger of the Purchaser with and into the Company (the “Merger”)
        pursuant to which all then outstanding Shares will be converted into the
        right
        to receive the Offer Price; 

       

      WHEREAS,
        each Stockholder is the beneficial owner of such number of Shares set forth
        opposite such Stockholder’s name on Schedule
        I
        hereto
        (such Shares, together with any other Equity Interests in the Company
        beneficially owned by such Stockholder and any other Shares and any other
        Equity
        Interests in the Company of which such Stockholder obtains beneficial ownership
        after the date hereof, being collectively referred to herein as the
“Covered
        Shares”
of
        such
        Stockholder); and

       

      WHEREAS,
        as a condition of and material inducement to Parent’s and the Purchaser’s
        willingness to enter into the Merger Agreement, each of the Stockholders
        has
        agreed to enter into this Agreement and tender and vote its Covered Shares
        as
        described herein.

       

      NOW,
        THEREFORE, in consideration of the foregoing and the respective representations,
        warranties, covenants and agreements set forth in this Agreement and in the
        Merger Agreement, and intending to be legally bound hereby, the parties hereto
        agree as follows:

       

      1. Certain
        Definitions.
        For the
        purposes of this Agreement, unless the context otherwise requires, capitalized
        terms used and not otherwise defined in this Agreement shall have the respective
        meanings ascribed to them in this Section
        1,
        or if
        no meaning is ascribed in this Section
        1
        or
        elsewhere in this Agreement, then such terms shall have the respective meanings
        ascribed to them in the Merger Agreement.

       

      “affiliate”
has
        the
        meaning set forth in the Merger Agreement; provided,
        however,
        that
        the Company shall be deemed not to be an affiliate of Stockholder for purposes
        of this Agreement.

       

      “beneficial
        ownership”
(and
        related terms such as “beneficially owned” or “beneficial owner”) has the
        meaning set forth in Rule 13d-3 under the Exchange Act. 


      
        
           

        

        
           

          
            

          

        

        
           

        

      

       

      “Transfer”
means,
        with respect to any Equity Interest or other security, including the Covered
        Shares, the direct or indirect transfer, pledge, hypothecation, encumbrance,
        assignment or other disposition (whether by sale, merger, consolidation,
        liquidation, dissolution, dividend, distribution or otherwise) of such Equity
        Interest or other security or the beneficial ownership thereof, the offer
        to
        make such a transfer or other disposition, and each option, agreement,
        arrangement or understanding, whether or not in writing, to effect any of
        the
        foregoing. As a verb, “Transfer”
shall
        have a correlative meaning.

       

      2. Stockholder
        Vote.

       

      (a) Voting
        Agreement.
        At any
        meeting of the stockholders of the Company, however called, or at any
        adjournment thereof, or in any other circumstance in which the vote, consent
        or
        other approval of the stockholders of the Company is sought (in writing or
        otherwise), each Stockholder shall, and shall instruct any holder of record
        of
        such Stockholder’s Covered Shares (except to the extent such Covered Shares have
        been tendered to Purchaser in the Offer) to, (i) appear at each such meeting
        or
        otherwise cause all of such Stockholder’s Covered Shares to be counted as
        present thereat for purposes of calculating a quorum and (ii) vote (or instruct
        to be voted), or execute and deliver a written consent (or cause a written
        consent to be executed and delivered) covering, all such Covered Shares (A)
        in
        favor of adopting the Merger Agreement (including for the purposes of this
        Section
        2(a),
        as it
        may be modified or amended from time to time), and the approval of the Merger
        and each of the other transactions contemplated by the Merger Agreement and
        this
        Agreement and any other matter that must be approved by the stockholders
        of the
        Company in order for the transactions contemplated by the Merger Agreement
        to be
        consummated, (B) only
        as
        directed by Parent, the Purchaser or any Parent Subsidiary with respect
        to
        any
        Acquisition Proposal, (C) only as directed by Parent, the Purchaser or any
        Parent Subsidiary with respect to any change in the business, management
        or
        Board of Directors of the Company (other than as directed by Parent, the
        Purchaser or any Parent Subsidiary) and (D) only as directed by Parent, the
        Purchaser or any Parent Subsidiary with respect to any proposal, action or
        Contract that would (1) impede, frustrate, prevent or nullify any provision
        of
        this Agreement, the Merger Agreement or the consummation of the Merger or
        other
        transactions contemplated thereby, (2) result in a breach in any respect
        of any
        covenant, representation, warranty or any other obligation or agreement of
        the
        Company under the Merger Agreement or (3) result in any of the conditions
        set
        forth in Article VI or Annex I of the Merger Agreement not being fulfilled
        or
        satisfied. Each Stockholder shall not commit or agree to take any action
        inconsistent with the foregoing.

       

      (b) Irrevocable
        Proxy.
        Solely
        for the purpose of effecting the votes or consents in Section
        2(a),
        substantially concurrently with the execution of this Agreement, each
        Stockholder agrees to deliver to Parent a proxy in the form attached as
Exhibit
        A
        hereto
        (the “Proxy”),
        which
        shall be irrevocable to the extent permitted by applicable Law, covering
        all of
        such Stockholder’s Covered Shares. Parent agrees not to exercise the Proxy for
        any other purpose. Each Stockholder hereby represents to Parent that any
        proxies
        heretofore given in respect of such Covered Shares are not irrevocable and
        that
        any such proxies are hereby revoked, and such Stockholder agrees to promptly
        notify the Company of such revocation. Each Stockholder hereby affirms that
        the
        Proxy is given in connection with the execution of the Merger Agreement and
        that
        the Proxy is given to secure the performance of the duties of such Stockholder
        under this Agreement. Each Stockholder hereby further affirms that the Proxy
        is
        coupled with an interest and may under no circumstances be revoked. Each
        Stockholder hereby ratifies and confirms all that the Proxy may lawfully
        do or
        cause to be done by virtue hereof. Without limiting the generality of the
        foregoing, the Proxy is executed and intended to be irrevocable in accordance
        with the provisions of Section 212 of the Delaware General Corporation Law.
        For
        the avoidance of doubt, if for any reason the Proxy is not irrevocable, each
        Stockholder agrees to continue to vote its Covered Shares in accordance with
        Section
        2(a)
        hereof.

       

      
        
           

        

        
          2

          
            

          

        

        
           

        

      

       

      3. Agreement
        to Tender.
        Each
        Stockholder shall validly tender (and shall not withdraw), pursuant to and
        in
        accordance with the terms of the Offer and the Offer Documents, such
        Stockholder’s Covered Shares into the Offer. In furtherance, and without
        limiting the generality, of the foregoing, on or prior to the Expiration
        Date,
        each Stockholder shall (i) deliver or cause to be delivered to the depositary
        designated in the Offer Documents (A) a letter of transmittal with respect
        to
        its Covered Shares in the form included in the Offer Documents and otherwise
        complying with the terms of the Offer, (B) any certificates representing
        its
        Covered Shares and (C) any and all other documents or instruments required
        to be
        delivered pursuant to the terms of the Offer or the Offer Documents, (ii)
        instruct and cause any other Person who is the holder of record of any Covered
        Shares beneficially owned by such Stockholder (including such Stockholder’s
        broker) to validly tender (and not withdraw, unless either the Offer or this
        Agreement terminates pursuant to Section 7 hereof) such Covered Shares pursuant
        to and in accordance with the terms and conditions of the Offer and the Offer
        Documents and (iii) take any and all other actions reasonably necessary to
        accomplish the foregoing. 

       

      4. No
        Disposition or Solicitation.

       

      (a) No
        Disposition or Adverse Act.
        Stockholder hereby covenants and agrees that, except as contemplated by this
        Agreement, the Merger Agreement and the Offer Documents, each Stockholder
        shall
        not (i) offer to Transfer, Transfer or consent to any Transfer of any or
        all of
        its Covered Shares or any interest therein without the prior written consent
        of
        Parent, (ii) enter into any Contract with respect to any Transfer of any
        of its
        Covered Shares or any interest therein, (iii) grant any proxy, power-of-attorney
        or other authorization or consent in or with respect to any of its Covered
        Shares, (iv) deposit any of its Covered Shares into a voting trust or enter
        into
        a voting agreement or arrangement with respect to any of its Covered Shares
        or
        (v) take any other action that would make any representation or warranty
        of such
        Stockholder contained herein untrue or incorrect in any material respect
        or in
        any way restrict, limit or interfere in any material respect with the
        performance of such Stockholder’s obligations hereunder or the transactions
        contemplated hereby or by the Merger Agreement; provided,
        that
        nothing in this Section 4(a) shall restrict or prohibit (x) the transfer
        of
        Covered Shares between and among accounts that are controlled by the
        Stockholder, if at all times such accounts hold Covered Shares, and which
        do not
        place prohibitions or restrictions on the ability of such Stockholder to
        perform
        any of its agreements or obligations hereunder or (y) the transfer of Covered
        Shares to any affiliate of the Stockholder who executes a similar Tender
        and
        Support Agreement. Any attempted Transfer of Covered Shares or any interest
        therein in violation of this Section
        4(a)
        shall be
        null and void.

       

      
        
           

        

        
          3

          
            

          

        

        
           

        

      

       

      (b) Non-Solicitation.
        Each
        Stockholder hereby agrees that Stockholder shall not, and shall not authorize
        its representatives and agents (including its investment bankers, attorneys
        and
        accountants) (collectively, its “Representatives”)
        to,
        directly or indirectly, (i) initiate, solicit or knowingly facilitate or
        encourage (including by way of providing information) the submission of any
        inquiries, proposals or offers or any other efforts or attempts that constitute,
        or may reasonably be expected to lead to, any Acquisition Proposal or engage
        in
        any discussions or negotiations with respect thereto, (ii) approve or recommend,
        or publicly propose to approve or recommend, any Acquisition Proposal, (iii)
        make any statement or proposal inconsistent with the Company Board
        Recommendation or (iv) enter into any merger agreement, letter of intent,
        agreement in principle, share purchase agreement, asset purchase agreement,
        share exchange agreement, option agreement or other similar Contract relating
        to
        an Acquisition Proposal or enter into any Contract or agreement in principle
        requiring such Stockholder to abandon, terminate or breach its obligations
        hereunder or fail to consummate the transactions contemplated hereby. Each
        Stockholder shall immediately cease and cause to be terminated any solicitation,
        encouragement, discussion or negotiation with any Persons conducted theretofore
        by such Stockholder or any of its Representatives with respect to any
        Acquisition Proposal. Each Stockholder shall promptly notify Parent in writing
        of any Acquisition Proposal (and in any event less than 24 hours following
        the
        receipt of such Acquisition Proposal), such notice to include the identity
        of
        any Person approaching such Stockholder with an Acquisition Proposal, and
        a copy
        of any such Acquisition Proposal (or, where no such copy is available, a
        reasonably detailed description of such Acquisition Proposal), including
        any
        modifications thereto. Any violation of the foregoing restrictions by a
        Stockholder or any of its Representatives shall be deemed to be a material
        breach of this Agreement by such Stockholder.

       

      5. Waiver
        of Appraisal and Dissenters’ Rights and Actions.
        Each
        Stockholder hereby (i) waives and agrees not to exercise any rights of appraisal
        or rights to dissent from the Merger that Stockholder may have and (ii) agrees
        not to commence or participate in, and agrees to take all actions necessary to
        opt out of any class in any class action with respect to, any claim, derivative
        or otherwise, against Parent, the Purchaser, the Company or any of their
        respective successors relating to the negotiation, execution or delivery
        of this
        Agreement or the Merger Agreement or the consummation of the Offer or the
        Merger, including any claim (x) challenging the validity of, or seeking to
        enjoin the operation of, any provision of this Agreement or (y) alleging
        a
        breach of any fiduciary duty of the Board of Directors of the Company in
        connection with the Merger Agreement or the transactions contemplated
        thereby.

       

      6. Representations
        and Warranties of Stockholder.
        Each
        Stockholder hereby represents and warrants to Parent as follows: 

       

      (a) Title.
        Such
        Stockholder is the sole record or beneficial owner of the Shares set forth
        opposite such Stockholder’s name on Schedule
        I.
        Such
        Shares constitute all of the capital stock and any other Equity Interests
        in the
        Company owned of record or beneficially by such Stockholder on the date hereof
        and except for such Shares, such Stockholder is the beneficial owner of,
        or has
        any right to acquire (whether currently, upon lapse of time, following the
        satisfaction of any conditions, upon the occurrence of any event or any
        combination of the foregoing), any Shares or any other Equity Interests in
        the
        Company. Such Stockholder has sole voting power and sole power of disposition
        with respect to the matters set forth in this Agreement, in each case with
        respect to all of the Shares set forth opposite such Stockholder’s name on
Schedule
        I
        with no
        limitations, qualifications or restrictions on such rights, subject to
        applicable securities Laws and the terms of this Agreement. Except as permitted
        by this Agreement, such Shares and any certificates representing such Shares,
        are now, and at all times during the term hereof will be, held by such
        Stockholder, or by a nominee or custodian for the benefit of such Stockholder,
        free and clear of any and all liens, pledges, claims, options, proxies, voting
        trusts or agreements, security interests, understandings or arrangements
        or any
        other encumbrances whatsoever on title, transfer or exercise of any rights
        of a
        stockholder in respect of such Shares (other than as created by this Agreement
        or under the terms of margin or prime brokerage accounts in which such Shares
        are held that do not prohibit or restrict the ability of the Stockholder
        to
        perform its obligations hereunder and that would not be applicable to the
        Shares
        from and after the tender of such Shares in the Offer) (collectively,
“Liens”).
        

       

      
        
           

        

        
          4

          
            

          

        

        
           

        

      

       

      (b) Organization
        and Qualification.
        Such
        Stockholder, if not an individual, is a legal organization duly organized
        and
        validly existing in good standing under the Laws of the jurisdiction of its
        organization. 

       

      (c) Authority.
        Such
        Stockholder has all necessary power and authority and legal capacity to execute
        and deliver this Agreement, to perform its obligations hereunder, and to
        consummate the transactions contemplated hereby, and no other proceedings
        or
        actions on the part of such Stockholder are necessary to authorize the
        execution, delivery or performance of this Agreement or the consummation
        of the
        transactions contemplated hereby. 

       

      (d) Due
        Execution and Delivery.
        This
        Agreement has been duly and validly executed and delivered by such Stockholder
        and, assuming due authorization, execution and delivery hereof by Parent,
        constitutes a legal, valid and binding agreement of Stockholder, enforceable
        against such Stockholder in accordance with its terms. If such Stockholder
        is
        married, and any of the Covered Shares constitute community property or spousal
        approval is otherwise necessary for this Agreement to be legal, binding and
        enforceable, this Agreement has been duly authorized, executed and delivered
        by,
        and constitutes the legal, valid and binding obligation of, such Stockholder’s
        spouse, enforceable in accordance with its terms.

       

      (e) No
        Filings; No Conflict or Default.
        No
        filing with, and no permit, authorization, consent or approval of, any
        Governmental Entity or any other Person is necessary for the execution and
        delivery of this Agreement by such Stockholder, the consummation by such
        Stockholder of the transactions contemplated hereby or the compliance by
        such
        Stockholder with the provisions hereof. None of the execution and delivery
        of
        this Agreement by such Stockholder, the consummation by such Stockholder
        of the
        transactions contemplated hereby or compliance by such Stockholder with any
        of
        the provisions hereof will (i) result in a violation or breach of, or constitute
        (with or without notice or lapse of time or both) a default (or give rise
        to any
        third party right of termination, cancellation, modification or acceleration)
        under, any of the terms, conditions or provisions of any note, bond, mortgage,
        indenture, lease, license, permit, Contract, commitment, arrangement,
        understanding, agreement or other instrument or obligation of any kind,
        including any voting agreement, proxy arrangement, pledge agreement,
        shareholders agreement or voting trust, to which such Stockholder is a party
        or
        by which such Stockholder or any of Stockholder’s properties or assets may be
        bound, (ii) violate any judgment, order, writ, injunction, decree or award
        of
        any court, administrative agency or other Governmental Entity that is applicable
        to such Stockholder or any of such Stockholder’s properties or assets, (iii)
        constitute a violation by such Stockholder of any Law or regulation of any
        jurisdiction, (iv) render Section 203 of the DGCL, or any other state takeover
        statute or similar statute or regulation, applicable to the Merger, the Offer
        or
        any other transaction involving Parent, the Purchaser or any Parent Subsidiary
        or (v) to the extent such Stockholder is not an individual, contravene or
        conflict with such Stockholder’s organizational documents, in each case, except
        for any conflict, breach, default or violation described which would not
        adversely effect in any material respect the ability of such Stockholder
        to
        perform its obligations hereunder or consummate the transactions contemplated
        hereby.

       

      
        
           

        

        
          5

          
            

          

        

        
           

        

      

       

      (f) No
        Litigation.
        There
        is no suit, claim, action, investigation or proceeding pending or, to the
        knowledge of such Stockholder, threatened against such Stockholder at Law
        or in
        equity before or by any Governmental Entity that could reasonably be expected
        to
        impair the ability of such Stockholder to perform its obligations hereunder
        or
        consummate the transactions contemplated hereby.

       

      (g) No
        Fees.
        No
        broker, investment banker, financial advisor or other Person is entitled
        to any
        broker’s, finder’s, financial advisor’s or other similar fee or commission in
        connection with the transactions contemplated hereby based upon arrangements
        made by or on behalf of such Stockholder.

       

      (h) Receipt;
        Reliance.
        Such
        Stockholder has received and reviewed a copy of the Merger Agreement. Such
        Stockholder understands and acknowledges that Parent and the Purchaser are
        entering into the Merger Agreement in reliance upon such Stockholder’s
        execution, delivery and performance of this Agreement.

       

      7. Termination.
        The
        term (the “Term”)
        of
        this Agreement and the Proxy granted pursuant hereto, with respect to any
        Stockholder, shall commence on the date hereof and shall terminate upon the
        earliest of (i) the mutual written agreement of Parent and such Stockholder,
        (ii) the Effective Time, (iii) the termination of the Merger Agreement in
        accordance with its terms, (iv) the acquisition by Parent of all of the Covered
        Shares, whether pursuant to the Offer or otherwise, (v) the termination of
        the
        Offer prior to the Acceptance Time and (vi) the Company having effected a
        Change
        in Board Recommendation pursuant to and in accordance with Section 5.4 of
        the
        Merger Agreement; provided
        that
        nothing herein shall relieve any party hereto from liability for any breach
        of
        this Agreement and Sections
        7
        and
9
        shall
        survive any termination of this Agreement. Upon termination of this Agreement,
        any Covered Shares tendered into the Offer prior to such termination may
        be
        withdrawn from the Offer.

       

      8. 
        No
        Limitation.
        Nothing
        in this Agreement shall be construed to prohibit any Stockholder or any of
        such
        Stockholder’s Representatives who
        is an
        officer or member of the Board of Directors of the Company from taking any
        action in his or her capacity as an officer or member of the Board of Directors
        of the Company or, subject to the limitations set forth in the Merger Agreement,
        from taking any action with respect to any Acquisition Proposal as an officer
        or
        member of such Board of Directors. 

       

      9. Miscellaneous.

       

      (a) Entire
        Agreement.
        This
        Agreement (together with Schedule
        I
        and
Exhibit
        A)
        and the
        Proxy constitute the entire agreement of the parties and supersede all prior
        agreements and undertakings, both written and oral, among the parties, or
        any of
        them, with respect to the subject matter hereof.

       

      
        
           

        

        
          6

          
            

          

        

        
           

        

      

       

      (b) Reasonable
        Efforts.
        Subject
        to the terms and conditions of this Agreement, each of the parties hereto
        agrees
        to use all reasonable efforts to take, or cause to be taken, all actions,
        and to
        do, or cause to be done, all things necessary, proper or advisable under
        applicable Laws to consummate and make effective the transactions contemplated
        hereby. At the other party’s reasonable request and without further
        consideration, each party hereto shall execute and deliver such additional
        documents and take all such further lawful action as may be necessary or
        desirable to consummate and make effective, in the most expeditious manner
        practicable, the transactions contemplated hereby. Without limiting the
        foregoing, each Stockholder shall execute and deliver to Parent and any of
        its
        designees any additional proxies, including with respect to any Covered Shares
        acquired after the date hereof, reasonably requested by Parent in furtherance
        of
        this Agreement.

       

      (c) No
        Assignment.
        This
        Agreement shall not be assigned by operation of Law or otherwise without
        the
        prior written consent of the Stockholders (in the case of any assignment
        by
        Parent) or Parent (in the case of an assignment by any Stockholder);
provided
        that
        Parent may assign any of its rights and obligations hereunder, in whole or
        in
        part, to the Purchaser or any other Parent Subsidiary, but no such assignment
        shall relieve Parent of its obligations hereunder.

       

      (d) Binding
        Successors.
        Without
        limiting any other rights Parent may have hereunder in respect of any Transfer
        of the Covered Shares, each Stockholder agrees that this Agreement and the
        Proxy
        and the obligations hereunder and thereunder shall attach to the Covered
        Shares
        beneficially owned by such Stockholder and its affiliates and shall be binding
        upon any Person to which legal or beneficial ownership of such Covered Shares
        shall pass, whether by operation of Law or otherwise, including such
        Stockholder’s heirs, guardians, administrators or successors. 

       

      (e) Amendments.
        This
        Agreement may not be amended, changed, supplemented or otherwise modified
        except
        by an instrument in writing signed on behalf of Parent and each Stockholder
        against whom such amendment, change, supplement or modification is sought
        to be
        enforced.

       

      (f) Notice.
        Any
        notices or other communications required or permitted under, or otherwise
        given
        in connection with, this Agreement shall be in writing and shall be deemed
        to
        have been duly given (i) when delivered or sent if delivered in Person or
        sent
        by facsimile transmission (provided confirmation of facsimile transmission
        is
        obtained), (ii) on the fifth Business Day after dispatch by registered or
        certified mail, (iii) on the next Business Day if transmitted by national
        overnight courier or (iv) on the date delivered if sent by email (provided
        confirmation of email receipt is obtained), in each case as
        follows:

       

      If
        to
        the Stockholders:

       

      At
        the
        respective addresses and facsimile numbers set forth on Schedule
        I
        hereto.

       

      Copy
        to:

      Icahn
        Associates Corp.

      Law
        Department

      767
        Fifth
        Avenue, 47th
        Floor

      New
        York,
        NY 10153

      Telephone: 
        (212)
        702-4388

      Facsimile:    
        (212)
        688-1158

      Attention:   
        Keith
        Schaitkin


      
        
           

        

        
          7

          
            

          

        

        
           

        

      

      


      If
        to
        Parent:

       

      c/o
        Eli
        Lilly and Company

      Lilly
        Corporate Center

      Indianapolis,
        Indiana 46285 USA

      Telephone: (317)
        276-2000

      Facsimile:   
        (317)
        433-3000 

      Attention:  
        General
        Patent CounselCopy
        to:

       

      Latham
        & Watkins LLP

      885
        Third
        Avenue

      New
        York,
        New York 10022

      Tel:
        (212) 906-1770

      Fax:
        (212) 751-4864

      Attention:
        M. Adel Aslani-Far

      Email:
        adel.aslanifar@lw.com

       

      (g) Severability.
        If any
        term or other provision of this Agreement is invalid, illegal or incapable
        of
        being enforced by any rule of Law or public policy, all other conditions
        and
        provisions of this Agreement shall nevertheless remain in full force and
        effect
        so long as the economic or legal substance of the transactions contemplated
        hereby is not affected in any manner materially adverse to any party. Upon
        such
        determination that any term or other provision is invalid, illegal or incapable
        of being enforced, the parties hereto shall negotiate in good faith to modify
        this Agreement so as to effect the original intent of the parties as closely
        as
        possible in an acceptable manner to the end that transactions contemplated
        hereby are fulfilled to the extent possible.

       

      (h) Remedies.
        All
        rights, powers and remedies provided under this Agreement or otherwise available
        in respect hereof at Law or in equity shall be cumulative and not alternative,
        and the exercise of any such right, power or remedy by any party hereto shall
        not preclude the simultaneous or later exercise of any other such right,
        power
        or remedy by such party.

       

      (i) No
        Waiver.
        The
        failure of any party hereto to exercise any right, power or remedy provided
        under this Agreement or otherwise available in respect hereof at Law or in
        equity, or to insist upon compliance by any other party hereto with such
        party’s
        obligations hereunder, and any custom or practice of the parties at variance
        with the terms hereof, shall not constitute a waiver by such party of such
        party’s right to exercise any such or other right, power or remedy or to demand
        such compliance.

       

      
        
           

        

        
          8

          
            

          

        

        
           

        

      

       

      (j) No
        Third Party Beneficiaries.
        This
        Agreement shall be binding upon and inure solely to the benefit of each party
        hereto and their respective successors and assigns, and nothing in this
        Agreement, express or implied, is intended to or shall confer upon any other
        Person any right, benefit or remedy of any nature whatsoever under or by
        reason
        of this Agreement.

       

      (k) Governing
        Law.
        This
        Agreement, and all matters arising hereunder or in connection herewith, shall
        be
        governed by, and construed in accordance with, the Laws of the State of
        Delaware, without regard to Laws that may be applicable under conflicts of
        Laws
        principles (whether of the State of Delaware or any other jurisdiction) that
        would cause the application of the Laws of any jurisdiction other than the
        State
        of Delaware.

       

      (l) Submission
        to Jurisdiction.
        Each of
        the parties hereto hereby irrevocably and unconditionally submits, for itself
        and its property, to the exclusive jurisdiction of any Delaware State court,
        or
        Federal court of the United States of America, sitting in Delaware, and any
        appellate court from any thereof, in any action or proceeding arising out
        of or
        relating to this Agreement or the agreements delivered in connection herewith
        or
        the transactions contemplated hereby or thereby or for recognition or
        enforcement of any judgment relating thereto, and each of the parties hereby
        irrevocably and unconditionally (i) agrees not to commence any such action
        or
        proceeding except in such courts, (ii) agrees that any claim in respect of
        any
        such action or proceeding may be heard and determined in such Delaware State
        court or, to the extent permitted by Law, in such Federal court, (iii) waives,
        to the fullest extent it may legally and effectively do so, any objection
        which
        it may now or hereafter have to the laying of venue of any such action or
        proceeding in any such Delaware State or Federal court, and (iv) waives,
        to the
        fullest extent permitted by Law, the defense of an inconvenient forum to
        the
        maintenance of such action or proceeding in any such Delaware State or Federal
        court. Each of the parties hereto agrees that a final judgment in any such
        action or proceeding shall be conclusive and may be enforced in other
        jurisdictions by suit on the judgment or in any other manner provided by
        Law.
        Each party to this Agreement irrevocably consents to service of process in
        the
        manner provided for notices in Section
        9(f).
        Nothing
        in this Agreement will affect the right of any party to this Agreement to
        serve
        process in any other manner permitted by Law.

       

      (m) Waiver
        of Jury Trial.
        EACH
        PARTY ACKNOWLEDGES AND AGREES THAT ANY CONTROVERSY WHICH MAY ARISE UNDER
        THIS
        AGREEMENT IS LIKELY TO INVOLVE COMPLICATED AND DIFFICULT ISSUES, AND THEREFORE
        IT HEREBY IRREVOCABLY AND UNCONDITIONALLY WAIVES ANY RIGHT IT MAY HAVE TO
        A
        TRIAL BY JURY IN RESPECT OF ANY LITIGATION DIRECTLY OR INDIRECTLY ARISING
        OUT OF
        OR RELATING TO THIS AGREEMENT AND ANY OF THE AGREEMENTS DELIVERED IN CONNECTION
        HEREWITH OR THE TRANSACTIONS CONTEMPLATED HEREBY OR THEREBY. EACH PARTY
        CERTIFIES AND ACKNOWLEDGES THAT (I) NO REPRESENTATIVE, AGENT OR ATTORNEY
        OF ANY
        OTHER PARTY HAS REPRESENTED, EXPRESSLY OR OTHERWISE, THAT SUCH OTHER PARTY
        WOULD
        NOT, IN THE EVENT OF LITIGATION, SEEK TO ENFORCE EITHER OF SUCH WAIVERS,
        (II) IT
        UNDERSTANDS AND HAS CONSIDERED THE IMPLICATIONS OF SUCH WAIVERS, (III) IT
        MAKES
        SUCH WAIVERS VOLUNTARILY, AND (IV) IT HAS BEEN INDUCED TO ENTER INTO THIS
        AGREEMENT BY, AMONG OTHER THINGS, THE MUTUAL WAIVERS AND CERTIFICATIONS IN
        THIS
SECTION
        9(m).

       

      
        
           

        

        
          9

          
            

          

        

        
           

        

      

       

      (n) Specific
        Performance.
        The
        parties hereto agree that irreparable damage would occur in the event that
        any
        of the provisions of this Agreement were not performed in accordance with
        their
        specific terms or were otherwise breached. It is accordingly agreed that
        the
        parties shall be entitled, without the securing or posting of any bond,
        guarantee or other undertaking, to an injunction or injunctions to prevent
        breaches of this Agreement and to enforce specifically the terms and provisions
        hereof in any court of the United States or any state having jurisdiction,
        this
        being in addition to any other remedy to which they are entitled at Law or
        in
        equity. In any action for specific performance, the parties will waive the
        defense of adequacy of a remedy at law.

       

      (o) Interpretation.
        Each
        party hereto has participated in the drafting of this Agreement, which each
        party acknowledges is the result of extensive negotiations between the parties.
        If an ambiguity or question of intent or interpretation arises, this Agreement
        shall be construed as if drafted jointly by the parties, and no presumption
        or
        burden of proof shall arise favoring or disfavoring any party by virtue of
        the
        authorship of any provision. For purposes of this Agreement, whenever the
        context requires: the singular number shall include the plural, and vice
        versa;
        the masculine gender shall include the feminine and neuter genders; the feminine
        gender shall include the masculine and neuter genders; and the neuter gender
        shall include masculine and feminine genders. As used in this Agreement,
        the
        words “include” and “including,” and variations thereof, shall not be deemed to
        be terms of limitation, but rather shall be deemed to be followed by the
        words
“without limitation.” Except as otherwise indicated, all references in this
        Agreement to “Sections,” “Exhibits,” “Annexes” and “Schedules” are intended to
        refer to Sections of this Agreement and Exhibits, Annexes and Schedules to
        this
        Agreement. All references in this Agreement to “$” are intended to refer to U.S.
        dollars. Unless otherwise specifically provided for herein, the term “or” shall
        not be deemed to be exclusive.

       

      (p) Counterparts.
        This
        Agreement may be executed in one or more counterparts, and by the different
        parties hereto in separate counterparts, each of which when executed shall
        be
        deemed to be an original but all of which taken together shall constitute
        one
        and the same agreement.

       

      (q) Expenses.
        Except
        as otherwise provided herein, all costs and expenses incurred by the parties
        hereto shall be borne solely and entirely by the party which has incurred
        the
        same.

       

      (r) No
        Ownership Interest. Nothing
        contained in this Agreement shall be deemed, upon execution, to vest in Parent
        any direct or indirect ownership or incidence of ownership of or with respect
        to
        any Covered Shares. All rights, ownership and economic benefits of and relating
        to the Covered Shares shall remain vested in and belong to the Stockholders,
        and
        Parent shall have no authority to manage, direct, superintend, restrict,
        regulate, govern or administer any of the policies or operations of the Company
        or exercise any power or authority to direct any Stockholder in the voting
        of
        any of the Covered Shares, except as otherwise provided herein.

       

      
        
           

        

        
          10

          
            

          

        

        
           

        

      

       

      [Signature
        page follows.]

       

      
        
           

        

        
          11

          
            

          

        

        
           

        

      


      IN
        WITNESS WHEREOF, Parent and Stockholder have caused this Agreement to be
        duly
        executed as of the day and year first above written.

       

      
        	 	
                ELI
                  LILLY AND COMPANY

              
	 	 	 
	 	
                By:

              	
                /s/
                  Gino Santini

              
	 	
                Name:
                  Gino Santini

              
	 	
                Title:
                  Vice President

              
	 	 
	 	
                ICAHN
                  ENTERPRISES HOLDINGS L.P.

              
	 	 
	 	
                By:
                  Icahn Enterprises G.P. Inc., general partner

              
	 	 
	
                By:
                  

              	
                /s/
                  Keith Meister

              
	 	
                Name:
                  Keith Meister

              
	 	
                Title:
                  Vice Chairman

              


      

      
      

       

       [Signature
        page to Tender and Support Agreement]

       

      
        
           

        

        
           

          
            

          

        

        
           

        

      


      SCHEDULE
        I

       

      
        	
                Name
                  and Contact Information for Stockholder

              	 	
                Number
                  of Shares 

                Beneficially
                  Owned

              	 
	 	 	 	 
	
                Icahn
                  Enterprises Holdings LP

                445
                  Hamilton Avenue

                Suite
                  1210

                White
                  Plains, NY 10601

              	 	 	
                4,563,610

              	 


      

       

      
        
           

        

        
           

          
            

          

        

        
           

        

      

       

      EXHIBIT
        A

       

      FORM
        OF IRREVOCABLE PROXY

       

      The
        undersigned stockholder (“Stockholder”)
        of
        ImClone Systems Incorporated, a Delaware corporation (the “Company”),
        hereby (i) irrevocably grants to, and appoints, Eli Lilly and Company, a
        Delaware corporation (“Parent”),
        and
        any person designated in writing by Parent, and each of them individually,
        Stockholder’s proxy and attorney-in-fact (with full power of substitution), for
        and in the name, place and stead of Stockholder, to vote all of the Covered
        Shares or grant a consent or approval in respect of the Covered Shares, in
        accordance with the terms of this Proxy and (ii) revokes any and all proxies
        heretofore given in respect of the Covered Shares. 

       

      This
        Proxy is granted pursuant to that certain Tender and Support Agreement, dated
        as
        of the date hereof, by and among Parent, Stockholder and certain other
        stockholders of the Company named therein (the “Support
        Agreement”).
        For
        the purposes of this Proxy, “Covered
        Shares”
means
        (i) all shares of common stock, par value $0.001 per share, of the Company
        (“Company
        Common Stock”)
        and
        the associated preferred stock purchase rights issued in connection with
        and
        subject to the Rights Agreement, dated as of February 15, 2002 and amended
        on
        May 4, 2006, between the Company and EquiServe Trust Company, N.A., as Rights
        Agent and any other equity interests in the Company which are beneficially
        owned
        by Stockholder or any of its affiliates as of the date hereof and (ii) all
        shares of Company Common Stock and any other equity interests in the Company
        which are beneficially owned by Stockholder or any of its affiliates and
        are
        acquired after the date hereof and prior to the termination of the Support
        Agreement. The Covered Shares as of the date hereof are set forth on the
        signature page hereof. This Proxy shall terminate and be of no further force
        and
        effect immediately upon termination of the Support Agreement. 

       

      Stockholder
        hereby affirms that the irrevocable proxy set forth in this Proxy is given
        in
        connection with the execution of that certain Agreement and Plan of Merger
        (the
“Merger
        Agreement”),
        dated
        as of the date hereof, by and among Parent, Alaska Acquisition Corporation,
        a
        Delaware corporation (the “Purchaser”),
        and
        the Company, providing, among other things, for (i) an offer by the Purchaser
        to
        purchase all of the outstanding shares of Company Common Stock and the
        associated Company Rights (as defined in the Merger Agreement) and (ii)
        following the acceptance for payment of shares of Company Common Stock and
        the
        associated Company Rights pursuant to the Offer, the merger of the Purchaser
        with and into the Company (the “Merger”),
        and
        that such irrevocable proxy is given to secure the performance of the duties
        of
        Stockholder under the Support Agreement. Stockholder hereby further affirms
        that
        the irrevocable proxy set forth in this Proxy is coupled with an interest
        and
        may under no circumstances be revoked. Stockholder hereby ratifies and confirms
        all that such irrevocable proxy may lawfully do or cause to be done by virtue
        hereof. Without limiting the generality of the foregoing, this Proxy is executed
        and intended to be irrevocable in accordance with the provisions of Section
        212
        of the Delaware General Corporation Law.

       

      
        
           

        

        
           

          
            

          

        

        
           

        

      

       

      The
        attorneys-in-fact and proxies named above are hereby authorized and empowered
        by
        the undersigned at any time after the date hereof and prior to the termination
        of the Support Agreement to act as the undersigned’s attorney-in-fact and proxy
        to vote the Covered Shares, and to exercise all voting, consent and similar
        rights of the undersigned with respect to the Covered Shares (including,
        without
        limitation, the power to execute and deliver written consents), at every
        annual,
        special, adjourned or postponed meeting of the stockholders of the Company
        and
        in every written consent in lieu of such a meeting:

       

      
        	 	
                (A)

              	
                in
                  favor of adopting the Merger Agreement (including for the purposes
                  of this
                  Proxy, as it may be modified or amended from time to time), and
                  the
                  approval of the Merger and each of the other transactions contemplated
                  by
                  the Merger Agreement and the Support Agreement and any other matter
                  that
                  must be approved by the stockholders of the Company in order for
                  the
                  transactions contemplated by the Merger Agreement to be consummated,
                  

              


      

       

      
        	 	
                (B)

              	
                in
                  favor of any adjournment or postponement recommended by the Company
                  with
                  respect to any stockholder meeting with respect to the Merger Agreement
                  and the Merger, 

              


      

       

      
        	 	
                (C)

              	
                against
                  any Acquisition Proposal or any agreements, arrangements, commitments,
                  understandings, contracts, leases (whether for real or personal
                  property),
                  powers of attorney, notes, bonds, mortgages, indentures, deeds
                  of trust,
                  loans, evidences of indebtedness, purchase orders, letters of credit,
                  settlement agreements, franchise agreements, undertakings, covenants
                  not
                  to compete, employment agreements, licenses, instruments, obligations,
                  commitments, understandings, policies, purchase and sales orders,
                  quotations or other commitments (collectively, “Contracts”)
                  relating to an Acquisition Proposal,


              


      

       

      
        	 	
                (D)

              	
                against
                  any reorganization, recapitalization, dissolution, liquidation
                  or winding
                  up of or by the Company (other than the Merger),
                  

              


      

       

      
        	 	
                (E)

              	
                against
                  any change in the business, management or Board of Directors of
                  the
                  Company (other than as directed by Parent, the Purchaser or any
                  Parent
                  Subsidiary); and 

              


      

       

      
        	 	
                (F)

              	
                against
                  any proposal, action or Contract that would (1) impede, frustrate,
                  prevent
                  or nullify any provision of the Support Agreement, the Merger Agreement
                  or
                  the Merger, (2) result in a breach in any respect of any covenant,
                  representation, warranty or any other obligation or agreement of
                  the
                  Company under the Merger Agreement, (3) result in any of the conditions
                  set forth in Article VI or Annex I of the Merger Agreement not
                  being
                  fulfilled or satisfied or (4) except as expressly contemplated
                  by the
                  Merger Agreement, change in any manner the dividend policy or
                  capitalization of, including the voting rights of any class of
                  equity
                  interests in, the Company. 

              


      

       

      Any
        obligation of the undersigned hereunder shall be binding upon the successors
        and
        assigns of the undersigned.

       

      
        
           

        

        
           

          
            

          

        

        
           

        

      


      Dated:
        October 6, 2008

       

      
        	
                ICAHN
                  ENTERPRISES HOLDINGS L.P.

              
	 	 
	
                By:

              	
                Icahn
                  Enterprises G.P. Inc., general partner

              
	 	 
	
                By:

              	
                /s/
                  Keith Meister

              
	 	
                Name:
                  Keith Meister

              
	 	
                Title:
                  Vice Chairman

              
	 	 
	
                Shares:

              	
                4,563,610

              


      

       

      [Signature
        Page to Proxy]