Exhibit 3.1

BY-LAWS AS AMENDED AND RESTATED AS OF OCTOBER 3, 2006

IMCLONE SYSTEMS INCORPORATED

ARTICLE I

STOCKHOLDERS

Section 1.1. Annual Meetings. An annual meeting of stockholders shall be held for the election of directors at such date, time and place either within or without the State of Delaware as may be designated by the Board of Directors from time to time. Any other proper business may be transacted at the annual meeting.

Section 1.2. Special Meetings. Special meetings of stockholders may be called at any time by the Chairman of the Board, if any, the Vice Chairman of the Board, if any, the President or the Board of Directors, to be held at such date, time and place either within or without the State of Delaware as may be stated in the notice of the meeting.

Section 1.3. Notice of Meetings. Whenever stockholders are required or permitted to take any action at a meeting, a written notice of the meeting shall be given which shall state the place, date and hour of the meeting, and, in the case of a special meeting, the purpose or purposes for which the meeting is called. Unless otherwise provided by law, the written notice of any meeting shall be given not less than ten nor more than sixty days before the date of the meeting to each stockholder entitled to vote at such meeting. If mailed, such notice shall be deemed to be given when deposited in the United States mail, postage prepaid, directed to the stockholder at such stockholder’s address as it appears on the records of the Corporation.

Section 1.4. Adjournments. Any meeting of stockholders, annual or special, may be adjourned from time to time, to reconvene at the same or some other place, and notice need not be given of any such adjourned meeting if the time and place thereof are announced at the meeting at which the adjournment is taken. At the adjourned meeting the Corporation may transact any business which might have been transacted at the original meeting. If the adjournment is for more than thirty days, or if after the adjournment a new record date is fixed for the adjourned meeting, a notice of the adjourned meeting shall be given to each stockholder of record entitled to vote at the meeting.

Section 1.5. Quorum. At each meeting of stockholders, except where otherwise provided by law or the certificate of incorporation or these by-laws, the holders of a majority of the outstanding shares of stock entitled to vote on a matter at the meeting, present in person or represented by proxy, shall constitute a quorum. In the absence of a quorum of the holders of any class of stock entitled to vote on a matter, the holders of such class so present or represented may, by majority vote, adjourn the meeting of such class from time to time in the manner provided by Section 1.4 of these by-laws until a quorum of such class shall be so present or represented. Shares of its own capital stock belonging on the record date for the meeting to the Corporation or to another corporation, if a majority of the shares entitled to vote in the election

of directors of such other corporation is held, directly or indirectly, by the Corporation, shall neither be entitled to vote nor be counted for quorum purposes; provided, however, that the foregoing shall not limit the right of the Corporation to vote stock, including but not limited to its own stock, held by it in a fiduciary capacity.

Section 1.6. Organization. Meetings of stockholders shall be presided over by the Chairman of the Board, if any, or in the absence of the Chairman of the Board by the Vice Chairman of the Board (if any), or in the absence of both the Chairman and Vice Chairman of the Board by the President (if any), or in the absence of the foregoing persons by a chairman designated by the Board of Directors, or in the absence of such designation by a chairman chosen at the meeting. The Secretary, or in the absence of the Secretary an Assistant Secretary, shall act as secretary of the meeting, but in the absence of the Secretary and any Assistant Secretary the chairman of the meeting may appoint any person to act as secretary of the meeting.

The order of business at each such meeting shall be as determined by the chairman of the meeting. The chairman of the meeting shall have the right and authority to prescribe such rules, regulations and procedures and to do all such acts and things as are necessary or desirable for the proper conduct of the meeting, including, without limitation, the establishment of procedures for the maintenance of order and safety, limitations on the time allotted to questions or comments on the affairs of the Corporation, restrictions on entry to such meeting after the time prescribed for the commencement thereof and the opening and closing of the voting polls.

Section 1.7. Inspectors. Prior to any meeting of stockholders, the Board of Directors or the President shall appoint one or more inspectors to act at such meeting and make a written report thereof and may designate one or more persons as alternate inspectors to replace any inspector who fails to act. If no inspector or alternate is able to act at the meeting of stockholders, the person presiding at the meeting shall appoint one or more inspectors to act at the meeting. Each inspector, before entering upon the discharge of his or her duties, shall take and sign an oath faithfully to execute the duties of inspector with strict impartiality and according to the best of his or her ability. The inspectors shall ascertain the number of shares outstanding and the voting power of each, determine the shares represented at the meeting and the validity of proxies and ballots, count all votes and ballots, determine and retain for a reasonable period a record of the disposition of any challenges made to any determination by the inspectors and certify their determination of the number of shares represented at the meeting and their count of all votes and ballots. The inspectors may appoint or retain other persons to assist them in the performance of their duties. The date and time of the opening and closing of the polls for each matter upon which the stockholders will vote at a meeting shall be announced at the meeting. No ballot, proxy or vote, nor any revocation thereof or change thereto, shall be accepted by the inspectors after the closing of the polls. In determining the validity and counting of proxies and ballots, the inspectors shall be limited to an examination of the proxies, any envelopes submitted therewith, any information provided by a stockholder who submits a proxy by telegram, cablegram or other electronic transmission from which it can be determined that the proxy was authorized by the stockholder, ballots and the regular books and records of the corporation, and they may also consider other reliable information for the limited purpose of reconciling proxies and ballots submitted by or on behalf of banks, brokers, their nominees or similar persons which represent more votes than the holder of a proxy is authorized by the record owner to cast or more votes than the stockholder holds of record. If the inspectors consider other reliable information for

such purpose, they shall, at the time they make their certification, specify the precise information considered by them, including the person or persons from whom they obtained the information, when the information was obtained, the means by which the information was obtained and the basis for the inspectors’ belief that such information is accurate and reliable.

Section 1.8. Voting; Proxies. Unless otherwise provided in the certificate of incorporation, each stockholder entitled to vote at any meeting of stockholders shall be entitled to one vote for each share of stock held by such stockholder which has voting power upon the matter in question. Each stockholder entitled to vote at a meeting of stockholders or to express consent or dissent to corporate action in writing without a meeting may authorize another person or persons to act for such stockholder by proxy, but no such proxy shall be voted or acted upon after three years from its date, unless the proxy provides for a longer period. A duly executed proxy shall be irrevocable if it states that it is irrevocable and if, and only as long as, it is coupled with an interest sufficient in law to support an irrevocable power, regardless of whether the interest with which it is coupled is an interest in the stock itself or an interest in the Corporation generally. A stockholder may revoke any proxy which is not irrevocable by attending the meeting and voting in person or by filing an instrument in writing revoking the proxy or another duly executed proxy bearing a later date with the Secretary of the Corporation. Voting at meetings of stockholders need not be by written ballot and need not be conducted by inspectors unless the holders of a majority of the outstanding shares of all classes of stock entitled to vote thereon present in person or represented by proxy at such meeting shall so determine. Directors shall be elected by a plurality of the votes of the shares present in person or represented by proxy at the meeting and entitled to vote on the election of directors. In all other matters, unless otherwise provided by law or by the certificate of incorporation or these by-laws, the affirmative vote of the holders of a majority of the shares present in person or represented by proxy at the meeting and entitled to vote on the subject matter shall be the act of the stockholders. Where a separate vote by class or classes is required, the affirmative vote of the holders of a majority of the shares of such class or classes present in person or represented by proxy at the meeting shall be the act of such class or classes, except as otherwise provided by law or by the certificate of incorporation or these by-laws.

Section 1.9. Fixing Date for Determination of Stockholders of Record. In order that the Corporation may determine the stockholders entitled to notice of or to vote at any meeting of stockholders or any adjournment thereof, the Board of Directors may fix a record date, which record date shall not precede the date upon which the resolution fixing the record date is adopted by the Board of Directors, and which record date shall not be more than sixty nor less than ten days before the date of such meeting. If no record date is fixed by the Board of Directors, the record date for determining stockholders entitled to notice of or to vote at a meeting of stockholders shall be at the close of business on the day next preceding the day on which notice is given, or, if notice is waived, at the close of business on the day next preceding the day on which the meeting is held. A determination of stockholders of record entitled to notice of or to vote at a meeting of stockholders shall apply to any adjournment of the meeting; provided, however, that the Board of Directors may fix a new record date for the adjourned meeting.

In order that the Corporation may determine the stockholders entitled to consent to corporate action in writing without a meeting, the Board of Directors may fix a record date, which record date shall not precede the date upon which the resolution fixing the record date is

adopted by the Board of Directors, and which date shall not be more than ten days after the date upon which the resolution fixing the record date is adopted by the Board of Directors. If no record date has been fixed by the Board of Directors, the record date for determining stockholders entitled to consent to corporate action in writing without a meeting, when no prior action by the Board of Directors is required by law, shall be the first date on which a signed written consent setting forth the action taken or proposed to be taken is delivered to the Corporation by delivery to its registered office in the State of Delaware, its principal place of business, or an officer or agent of the Corporation having custody of the book in which proceedings of meetings of stockholders are recorded. Delivery made to the Corporation’s registered office shall be by hand or by certified or registered mail, return receipt requested. If no record date has been fixed by the Board of Directors and prior action by the Board of Directors is required by law, the record date for determining stockholders entitled to consent to corporate action in writing without a meeting shall be at the close of business on the day on which the Board of Directors adopts the resolution taking such prior action.

In order that the Corporation may determine the stockholders entitled to receive payment of any dividend or other distribution or allotment of any rights or the stockholders entitled to exercise any rights in respect of any change, conversion or exchange of stock, or for the purpose of any other lawful action, the Board of Directors may fix a record date, which record date shall not precede the date upon which the resolution fixing the record date is adopted, and which record date shall be not more than sixty days prior to such action. If no record date is fixed, the record date for determining stockholders for any such purpose shall be at the close of business on the day on which the Board of Directors adopts the resolution relating thereto.

Section 1.10. List of Stockholders Entitled to Vote. The Secretary shall prepare and make, at least ten days before every meeting of stockholders, a complete list of the stockholders entitled to vote at the meeting, arranged in alphabetical order, and showing the address of each stockholder and the number of shares registered in the name of each stockholder. Such list shall be open to the examination of any stockholder, for any purpose germane to the meeting, during ordinary business hours, for a period of at least ten days prior to the meeting, either at a place within the city where the meeting is to be held, which place shall be specified in the notice of the meeting, or, if not so specified, at the place where the meeting is to be held. The list shall also be produced and kept at the time and place of the meeting during the whole time thereof and may be inspected by any stockholder who is present.

Section 1.11. Consent of Stockholders in Lieu of Meeting. Unless otherwise provided in the certificate of incorporation or by law, any action required by law to be taken at any annual or special meeting of stockholders of the Corporation, or any action which may be taken at any annual or special meeting of such stockholders, may be taken without a meeting, without prior notice and without a vote, if a consent or consents in writing, setting forth the action so taken, shall be signed by the holders of outstanding stock having not less than the minimum number of votes that would be necessary to authorize or take such action at a meeting at which all shares entitled to vote thereon were present and voted and shall be delivered to the Corporation by delivery to (a) its registered office in the State of Delaware by hand or by certified mail or registered mail, return receipt requested, (b) its principal place of business, or (c) an officer or agent of the Corporation having custody of the book in which proceedings of meetings of stockholders are recorded. Every written consent shall bear the date of signature of each

stockholder who signs the consent and no written consent shall be effective to take the corporate action referred to therein unless, within sixty days of the earliest dated consent delivered in the manner required by this by-law to the Corporation, written consents signed by a sufficient number of holders to take action are delivered to the Corporation by delivery to (a) its registered office in the State of Delaware by hand or by certified or registered mail, return receipt requested, (b) its principal place of business, or (c) an officer or agent of the Corporation having custody of the book in which proceedings of meetings of stockholders are recorded. Prompt notice of the taking of the corporate action without a meeting by less than unanimous written consent shall be given to those stockholders who have not consented in writing and who, if the action had been taken at a meeting, would have been entitled to notice of the meeting if the record date for such meeting had been the date that written consents signed by a sufficient number of stockholders to take the action were delivered to the Corporation as provided in this Section 1.11.

Section 1.12. Advance Notice of Stockholder Proposals. At any annual or special meeting of stockholders, proposals by stockholders and persons nominated for election as directors by stockholders shall be considered only if advance notice thereof has been timely given as provided herein and such proposals or nominations are otherwise proper for consideration under applicable law and the certificate of incorporation and by-laws of the Corporation. Notice of any proposal to be presented by any stockholder or of the name of any person to be nominated by any stockholder for election as a director of the Corporation at any meeting of stockholders shall be delivered to the Secretary of the Corporation at its principal executive office not less than 60 nor more than 90 days prior to the date of the meeting; provided, however, that if the date of the meeting is first publicly announced or disclosed (in a public filing or otherwise) less than 70 days prior to the date of the meeting, such advance notice shall be given not more than ten days after such date is first so announced or disclosed. Public notice shall be deemed to have been given more than 70 days in advance of the annual meeting if the Corporation shall have previously disclosed, in these by-laws or otherwise, that the annual meeting in each year is to be held on a determinable date, unless and until the Board determines to hold the meeting on a different date. Any stockholder who gives notice of any such proposal shall deliver therewith the text of the proposal to be presented and a brief written statement of the reasons why such stockholder favors the proposal and setting forth such stockholder’s name and address, the number and class of all shares of each class of stock of the Corporation beneficially owned by such stockholder and any material interest of such stockholder in the proposal (other than as a stockholder). Any stockholder desiring to nominate any person for election as a director of the Corporation shall deliver with such notice a statement in writing setting forth the name of the person to be nominated, the number and class of all shares of each class of stock of the Corporation beneficially owned by such person, the information regarding such person required by paragraphs (a), (e) and (f) of Item 401 of Regulation S-K adopted by the Securities and Exchange Commission (or the corresponding provisions of any regulation subsequently adopted by the Securities and Exchange Commission applicable to the Corporation), such person’s signed consent to serve as a director of the Corporation if elected, such stockholder’s name and address and the number and class of all shares of each class of stock of the Corporation beneficially owned by such stockholder. As used herein, shares “beneficially owned” shall mean all shares as to which such person, together with such person’s affiliates and associates (as defined in Rule 12b-2 under the Securities Exchange Act of 1934), may be deemed to beneficially own pursuant to Rules 13d-3 and 13d-5 under the Securities Exchange Act of 1934, as well as all shares as to

which such person, together with such person’s affiliates and associates, has the right to become the beneficial owner pursuant to any agreement or understanding, or upon the exercise of warrants, options or rights to convert or exchange (whether such rights are exercisable immediately or only after the passage of time or the occurrence of conditions). The person presiding at the meeting, in addition to making any other determinations that may be appropriate to the conduct of the meeting, shall determine whether such notice has been duly given and shall direct that proposals and nominees not be considered if such notice has not been given.

ARTICLE II

BOARD OF DIRECTORS

Section 2.1. Powers; Number; Qualifications. The business and affairs of the Corporation shall be managed by or under the direction of the Board of Directors, except as may be otherwise provided by law or in the certificate of incorporation. The Board of Directors shall consist of one or more members, the number thereof to be determined from time to time by the Board. Directors need not be stockholders.

Section 2.2. Election; Term of Office; Resignation; Removal; Vacancies. Each director shall hold office until his or her successor is elected and qualified or until his or her earlier resignation or removal. Any director may resign at any time upon written notice to the Board of Directors or to the President or the Secretary of the Corporation. Such resignation shall take effect at the time specified therein, and unless otherwise specified therein no acceptance of such resignation shall be necessary to make it effective. Any director or the entire Board of Directors may be removed, with or without cause, by the holders of a majority of the shares then entitled to vote at an election of directors. Unless otherwise provided in the certificate of incorporation or these by-laws, vacancies and newly created directorships resulting from any increase in the authorized number of directors elected by all of the stockholders having the right to vote as a single class or from any other cause may be filled by a majority of the directors then in office, although less than a quorum, or by the sole remaining director. Any director elected or appointed to fill a vacancy shall hold office until the next annual meeting of the stockholders and his or her successor is elected and qualified or until his or her earlier resignation or removal.

Section 2.3. Regular Meetings. Regular meetings of the Board of Directors may be held at such places within or without the State of Delaware and at such times as the Board may from time to time determine, and if so determined notice thereof need not be given.

Section 2.4. Special Meetings. Special meetings of the Board of Directors may be held at any time or place within or without the State of Delaware whenever called by the Chairman of the Board (if any), by the Vice Chairman of the Board (if any), or by any two directors. Reasonable notice thereof shall be given by the person or persons calling the meeting.

Section 2.5. Participation in Meetings by Conference Telephone Permitted. Unless otherwise restricted by the certificate of incorporation or these by-laws, members of the Board of Directors, or any committee designated by the Board, may participate in a meeting of the Board or of such committee, as the case may be, by means of conference telephone or similar communications equipment by means of which all persons participating in the meeting can hear

each other, and participation in a meeting pursuant to this by-law shall constitute presence in person at such meeting.

Section 2.6. Quorum; Vote Required for Action. At all meetings of the Board of Directors a majority of the entire Board shall constitute a quorum for the transaction of business. The vote of a majority of the directors present at a meeting at which a quorum is present shall be the act of the Board unless the certificate of incorporation or these by-laws shall require a vote of a greater number. In case at any meeting of the Board a quorum shall not be present, the members of the Board present may adjourn the meeting from time to time until a quorum shall be present.

Section 2.7. Organization. Meetings of the Board of Directors shall be presided over by the Chairman of the Board (if any), or in the absence of the Chairman of the Board, by the Vice Chairman of the Board (if any). In the absence of both the Chairman of the Board and the Vice Chairman of the Board, the Board shall elect from among its members a person who shall preside at any meeting of the Board of Directors. The Secretary, or in the absence of the Secretary an Assistant Secretary, shall act as secretary of the meeting, but in the absence of the Secretary and any Assistant Secretary the chairman of the meeting may appoint any person to act as secretary of the meeting.

Section 2.8. Action by Directors Without a Meeting. Unless otherwise restricted by the certificate of incorporation or these by-laws, any action required or permitted to be taken at any meeting of the Board of Directors, or of any committee thereof, may be taken without a meeting if all members of the Board or of such committee, as the case may be, consent thereto in writing, and the writing or writings are filed with the minutes of proceedings of the Board or committee.

Section 2.9. Compensation of Directors. Unless otherwise restricted by the certificate of incorporation or these by-laws, the Board of Directors shall have the authority to fix the compensation of directors. Directors shall be entitled to receive stock of the corporation and warrants, options and other rights to purchase stock of the corporation for their services rendered to the corporation if so determined by the Board of Directors.

Section 2.10. Chairman of the Board. The Chairman of the Board, if any, shall preside at all meetings of the Board of Directors and of the stockholders at which he or she shall be present and shall have and may exercise such powers as may, from time to time, be assigned to him or her by the Board or as may be provided by law.

Section 2.11 Vice Chairman of the Board. The Vice Chairman of the Board, if any, shall preside at meetings of the Board of Directors in which the Chairman of the Board is absent, and shall have and may exercise such powers as may, from time to time, be assigned to him or her by the Board or as may be provided by law.

ARTICLE III

COMMITTEES

Section 3.1. Committees. The Board of Directors may designate one or more committees, each committee to consist of one or more of the directors of the Corporation. The Board may designate one or more directors as alternate members of any committee, who may replace any absent or disqualified member at any meeting of the committee. Any such committee, to the extent provided in the resolution of the Board of Directors or in these by-laws, shall have and may exercise all the powers and authority of the Board of Directors in the management of the business and affairs of the Corporation, and may authorize the seal of the Corporation to be affixed to all papers which may require it; but no such committee shall have the power or authority in reference to the following matters: (i) approving or adopting, or recommending to the stockholders, any action or matter (other than the election or removal of directors) expressly required by law to be submitted to stockholders for approval, (ii) adopting, amending or repealing these By-Laws or (iii) removing or indemnifying directors.

Section 3.2. Committee Rules. Unless the Board of Directors otherwise provides, each committee designated by the Board may adopt, amend and repeal rules for the conduct of its business. In the absence of a provision by the Board or a provision in the rules of such committee to the contrary, a majority of the entire authorized number of members of such committee shall constitute a quorum for the transaction of business, the vote of a majority of the members present at a meeting at the time of such vote if a quorum is then present shall be the act of such committee, and in other respects each committee shall conduct its business in the same manner as the Board conducts its business pursuant to Article II of these by-laws.

ARTICLE IV

OFFICERS

Section 4.1. Officers; Election. As soon as practicable after the annual meeting of stockholders in each year, the Board of Directors shall elect a Chief Executive Officer and a Secretary, and it may, if it so determines, elect from among its members a Chairman of the Board and a Vice Chairman of the Board. The Board may also elect a President, one or more Vice Presidents, one or more Assistant Vice Presidents, one or more Assistant Secretaries, a Treasurer and one or more Assistant Treasurers and such other officers as the Board may deem desirable or appropriate and may give any of them such further designations or alternate titles as it considers desirable. Any number of offices may be held by the same person unless the certificate of incorporation or these by-laws otherwise provide.

Section 4.2. Term of Office; Resignation; Removal; Vacancies. Unless otherwise provided in the resolution of the Board of Directors electing any officer, each officer shall hold office until his or her successor is elected and qualified or until his or her earlier resignation or removal. Any officer may resign at any time upon written notice to the Board or to the Chief

Executive Officer or the Secretary of the Corporation. Such resignation shall take effect at the time specified therein, and unless otherwise specified therein no acceptance of such resignation shall be necessary to make it effective. The Board may remove any officer with or without cause at any time. Any such removal shall be without prejudice to the contractual rights of such officer, if any, with the Corporation, but the election of an officer shall not of itself create contractual rights. Any vacancy occurring in any office of the Corporation by death, resignation, removal or otherwise may be filled by the Board at any regular or special meeting.

Section 4.3. Chief Executive Officer. The Board shall designate a Chief Executive Officer who shall have general charge and supervision of the business of the Corporation and, in general, shall perform all duties incident to the office of chief executive officer of a corporation and such other duties as may, from time to time, be assigned to him or her by the Board or as may be provided by law.

Section 4.4. President. The Board may designate a President who shall perform all duties as may, from time to time, be assigned to him or her by the Board.

Section 4.5. Vice Presidents. The Vice President or Vice Presidents, at the request or in the absence of the Chief Executive Officer or during the Chief Executive Officer’s inability to act, shall perform the duties of the Chief Executive Officer, and when so acting shall have the powers of the Chief Executive Officer. If there be more than one Vice President, the Board of Directors may determine which one or more of the Vice Presidents shall perform any of such duties; or if such determination is not made by the Board, the Chief Executive Officer may make such determination; otherwise any of the Vice Presidents may perform any of such duties. The Vice President or Vice Presidents shall have such other powers and shall perform such other duties as may, from time to time, be assigned to him or her or them by the Board or the Chief Executive Officer or as may be provided by law.

Section 4.6. Secretary. The Secretary shall have the duty to record the proceedings of the meetings of the stockholders, the Board of Directors and any committees in a book to be kept for that purpose, shall see that all notices are duly given in accordance with the provisions of these by-laws or as required by law, shall be custodian of the records of the Corporation, may affix the corporate seal to any document the execution of which, on behalf of the Corporation, is duly authorized, and when so affixed may attest the same, and, in general, shall perform all duties incident to the office of secretary of a corporation and such other duties as may, from time to time, be assigned to him or her by the Board or the Chief Executive Officer or as may be provided by law.

Section 4.7. Treasurer. The Treasurer shall have charge of and be responsible for all funds, securities, receipts and disbursements of the Corporation and shall deposit or cause to be deposited, in the name of the Corporation, all moneys or other valuable effects in such banks, trust companies or other depositories as shall, from time to time, be selected by or under authority of the Board of Directors. If required by the Board, the Treasurer shall give a bond for the faithful discharge of his or her duties, with such surety or sureties as the Board may determine. The Treasurer shall keep or cause to be kept full and accurate records of all receipts and disbursements in books of the Corporation, shall render to the Chief Executive Officer and to the Board, whenever requested, an account of the financial condition of the Corporation, and, in

general, shall perform all the duties incident to the office of treasurer of a corporation and such other duties as may, from time to time, be assigned to him or her by the Board or the Chief Executive Officer or as may be provided by law.

Section 4.8. Other Officers. The other officers, if any, of the Corporation shall have such powers and duties in the management of the Corporation as shall be stated in a resolution of the Board of Directors which is not inconsistent with these by-laws and, to the extent not so stated, as generally pertain to their respective offices, subject to the control of the Board. The Board may require any officer, agent or employee to give security for the faithful performance of his or her duties.

ARTICLE V

STOCK

Section 5.1. Certificates. Every holder of stock in the Corporation shall be entitled to have a certificate signed by or in the name of the Corporation by the Chairman of the Board of Directors, if any, or the President or a Vice President, and by the Treasurer or an Assistant Treasurer, or the Secretary or an Assistant Secretary, of the Corporation, representing the number of shares of stock in the Corporation owned by such holder. If such certificate is manually signed by one officer or manually countersigned by a transfer agent or by a registrar, any other signature on the certificate may be a facsimile. In case any officer, transfer agent or registrar who has signed or whose facsimile signature has been placed upon a certificate shall have ceased to be such officer, transfer agent or registrar before such certificate is issued, it may be issued by the Corporation with the same effect as if such person were such officer, transfer agent or registrar at the date of issue.

Section 5.2. Lost, Stolen or Destroyed Stock Certificates; Issuance of New Certificates. The Corporation may issue a new certificate of stock in the place of any certificate theretofore issued by it, alleged to have been lost, stolen or destroyed, and the Corporation may require the owner of the lost, stolen or destroyed certificate, or such owner’s legal representative, to give the Corporation a bond sufficient to indemnify it against any claim that may be made against it on account of the alleged loss, theft or destruction of any such certificate or the issuance of such new certificate.

ARTICLE VI

MISCELLANEOUS

Section 6.1. Fiscal Year. The fiscal year of the Corporation shall be January 1 to December 31 in each year.

Section 6.2. Seal. The Corporation may have a corporate seal which shall have the name of the Corporation inscribed thereon and shall be in such form as may be approved from time to time by the Board of Directors. The corporate seal may be used by causing it or a facsimile thereof to be impressed or affixed or in any other manner reproduced.

Section 6.3. Waiver of Notice of Meetings of Stockholders, Directors and Committees. Whenever notice is required to be given by law or under any provision of the certificate of incorporation or these by-laws, a written waiver thereof, signed by the person entitled to notice, whether before or after the time stated therein, shall be deemed equivalent to notice. Attendance of a person at a meeting shall constitute a waiver of notice of such meeting, except when the person attends a meeting for the express purpose of objecting, at the beginning of the meeting, to the transaction of any business because the meeting is not lawfully called or convened. Neither the business to be transacted at, nor the purpose of, any regular or special meeting of the stockholders, directors or members of a committee of directors need be specified in any written waiver of notice unless so required by the certificate of incorporation or these by-laws.

Section 6.4. Indemnification of Directors, Officers and Employees. The Corporation shall indemnify to the full extent permitted by law any person made or threatened to be made a party to any action, suit or proceeding, whether civil, criminal, administrative or investigative, by reason of the fact that such person or such person’s testator or intestate is or was a director, officer or employee of the Corporation or serves or served at the request of the Corporation any other enterprise as a director, officer or employee. Expenses, including attorneys’ fees, incurred by any such person in defending any such action, suit or proceeding shall be paid or reimbursed by the Corporation promptly upon receipt by it of an undertaking of such person to repay such expenses if it shall ultimately be determined that such person is not entitled to be indemnified by the Corporation. The rights provided to any person by this by-law shall be enforceable against the Corporation by such person who shall be presumed to have relied upon it in serving or continuing to serve as a director, officer or employee as provided above. No amendment of this by-law shall impair the rights of any person arising at any time with respect to events occurring prior to such amendment. For purposes of this by-law, the term “Corporation” shall include any predecessor of the Corporation and any constituent corporation (including any constituent of a constituent) absorbed by the Corporation in a consolidation or merger; the term “other enterprise” shall include any corporation, partnership, joint venture, trust or employee benefit plan; service “at the request of the Corporation” shall include service as a director, officer or employee of the Corporation which imposes duties on, or involves services by, such director, officer or employee with respect to an employee benefit plan, its participants or beneficiaries; any excise taxes assessed on a person with respect to an employee benefit plan shall be deemed to be indemnifiable expenses; and action by a person with respect to an employee benefit plan which such person reasonably believes to be in the interest of the participants and beneficiaries of such plan shall be deemed to be action not opposed to the best interests of the Corporation.

Section 6.5. Interested Directors; Quorum. No contract or transaction between the Corporation and one or more of its directors or officers, or between the Corporation and any other corporation, partnership, association or other organization in which one or more of its directors or officers are directors or officers, or have a financial interest, shall be void or voidable solely for this reason, or solely because the director or officer is present at or participates in the meeting of the Board of Directors or committee thereof which authorizes the contract or transaction, or solely because his or her or their votes are counted for such purpose, if: (1) the material facts as to his or her relationship or interest and as to the contract or transaction are disclosed or are known to the Board or the committee, and the Board or committee in good faith authorizes the contract or transaction by the affirmative votes of a majority of the disinterested directors, even though the disinterested directors be less than a quorum; or (2) the material facts

as to his or her relationship or interest and as to the contract or transaction are disclosed or are known to the stockholders entitled to vote thereon, and the contract or transaction is specifically approved in good faith by vote of the stockholders; or (3) the contract or transaction is fair as to the Corporation as of the time it is authorized, approved or ratified, by the Board, a committee thereof or the stockholders. Common or interested directors may be counted in determining the presence of a quorum at a meeting of the Board of Directors or of a committee which authorizes the contract or transaction.

Section 6.6. Form of Records. Any records maintained by the Corporation in the regular course of its business, including its stock ledger, books of account and minute books, may be kept on, or be in the form of, punch cards, magnetic tape, photographs, microphotographs or any other information storage device, provided that the records so kept can be converted into clearly legible form within a reasonable time. The Corporation shall so convert any records so kept upon the request of any person entitled to inspect the same.

Section 6.7. Amendment of By-Laws. These by-laws may be amended or repealed, and new by-laws adopted, by the Board of Directors, but the stockholders entitled to vote may adopt additional by-laws and may amend or repeal any by-law whether or not adopted by them.

Delaware	0-19612	04-2834797
(State or other jurisdiction of	(Commission File Number)	(IRS Employer
Incorporation)		Identification No.)

Exhibit No.	Description
3.1		By-Laws of ImClone Systems Incorporated as amended and restated October 3, 2006

99.1		Press Release of ImClone Systems Incorporated dated October 3, 2006

	IMCLONE SYSTEMS INCORPORATED
	(Registrant)

Dated October 3, 2006	By:	/s/ Daniel J. O’Connor
		Daniel J. O’Connor
		Vice President, Interim General Counsel and Secretary

Exhibit No.		Description

3.1		By-Laws of ImClone Systems Incorporated as amended and restated October 3, 2006

99.1		Press Release of ImClone Systems Incorporated dated October 3, 2006

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