The Board of Directors (the “Board”) of Human Genome Sciences, Inc. (the “Corporation”), represents the stockholders’ interest in perpetuating a successful business and optimizing long-term financial returns. The Board is responsible for establishing the Corporation’s policies and strategies and for regularly monitoring the effectiveness of management in carrying out those policies and strategies. The Board is accountable to the stockholders of the Corporation. The Board has adopted these guidelines as part of the Board’s commitment to these principles.

Board Composition and Related Matters

1. Selection of Chairman and Chief Executive Officer

   The Board believes that it should be free to make this choice in a manner that it determines to be best for the Corporation at a given point in time. The Board does not have a policy on whether or not the roles of Chief Executive Officer and Chairman should be separate and, if they are to be separate, whether the Chairman should be selected from the non-employee Directors or be an employee.

2. Size of the Board

   The Board should periodically review its appropriate size and determine the optimum size that permits diversity of experience, while fostering effective interaction and productivity. At this time, the Board believes that 8 to 13 members is the optimum size range for this Board.

3. Composition of Board

   The Board believes that the Board should be composed of a substantial majority of independent Directors and that the Chief Executive Officer should be a Director. The Board believes that it may be appropriate to have other members of management serve as Directors, depending upon various facts and circumstances.

4. Board Definition of What Constitutes Independence for Outside Directors

   The Corporation will comply at all times with the requirements for independent directors as established by the National Association of Securities Dealers, Inc. (“NASD”), federal law and the rules of the Securities and Exchange Commission (“SEC”).

5. Lead Independent Director

   The Board shall designate one independent director as the Lead Independent Director. This Director is responsible for coordinating the activities of the other independent Directors, presiding at non-management meetings of the independent directors and performing various other duties. The Board believes that the Lead Independent Director should serve in that capacity for no longer than five consecutive years. If the Chairman is not employed by or an officer of the Company, the Chairman shall be designated as the Lead Independent Director, unless otherwise specified by the Board.

6. Board Membership Criteria

   The Nominating and Corporate Governance Committee is responsible for developing criteria for selecting candidates for election as Directors and identifying, evaluating (including inquiries into the background of candidates), recruiting and nominating candidates. In identifying candidates for membership on the Board, this Committee takes into account all factors it considers appropriate, which may include strength of character, maturity of judgment, career specialization, relevant skills, diversity and the extent to which a particular candidate would fill a present need on the Board of Directors. The Nominating and Corporate Governance Committee also reviews and determines whether existing members of the Board should stand for reelection, taking into consideration matters relating to the age and number of terms served by individual Directors and changes in the needs of the Board.

7. Directors Who Change Their Affiliations

   Any director who retires from or changes his or her employment or otherwise has a material change in professional responsibilities, occupation or business association shall give written notice to the Chairperson of the Nominating and Corporate Governance Committee as soon as possible, specifying the details of such change(s) and tendering his or her resignation from the Board and from each Board committee on which he or she serves. The Nominating and Corporate Governance Committee will consider the change(s) and all relevant factors and make a recommendation to the Board regarding whether to accept the proposed resignation or permit the director to continue to serve on the Board. The director whose membership is being reviewed shall not participate in the review or vote on the matter. It is the Board's belief that not every change in circumstances will require that a director leave the Board. The resignation which is tendered is not effective unless and until it is accepted by the Board..

8. Inside Director’s Termination of Employment or Retirement

   Any officer of the Corporation serving as a Director shall tender his resignation from the Board upon termination of employment or retirement from the Corporation. The Board will decide whether to accept the resignation.

9. Director Orientation and Continuing Education

   The Nominating and Corporate Governance Committee is responsible for establishing appropriate director orientation and continuing education programs in order to assure that all Directors have a fundamental understanding of the Corporation’s business and their duties and responsibilities as Directors.

10. Term Limits

    The Board does not believe it should establish term limits for Directors. The Board understands that term limits could help ensure that there are fresh ideas and viewpoints available to the Board. However, the Board believes that term limits hold the disadvantage of losing the contribution of Directors who over time have developed increasing insight into the Corporation and its operations and therefore provide an increasing contribution to the Board as a whole. The Board will consider each incumbent Director’s tenure on the Board when considering whether to renominate that Director for an additional term on the Board.

11. Conflicts of Interests

    Directors are expected to avoid any action, position or interest that conflicts with an interest of the Corporation, or gives the appearance of a conflict. The Board shall annually obtain information from each Director in order to monitor potential conflicts of interests, and Directors are expected to be mindful of their fiduciary obligations to the Corporation.

12. Board Compensation

    The Board believes that it must offer a fair and competitive compensation package to the Directors in order to attract and retain highly qualified individuals. The Compensation Committee should periodically review Board compensation in light of then current circumstances. Changes in Board compensation, if any, should come at the recommendation of the Compensation Committee, after full discussion and concurrence by the Board. Directors who are employees of the Corporation shall receive no additional remuneration for serving on the Board. Directors who are on the Corporation’s audit committee shall receive no additional remuneration, in the form of consulting fees or other special benefits, beyond that provided for service on the Board. The Board is committed to fostering compensation programs and policies designed to encourage Director stock ownership over the long-term. In the view of the Board, these programs and policies help align the interests of Directors with those of the Corporation’s stockholders.

13. Stock Ownership and Retention Guidelines for Non-Employee Directors

    The Board believes that non-employee directors should have a significant personal financial stake in the Company’s performance. Consequently, each non-employee director shall acquire and hold shares of the Company’s common stock having an initial investment value equal to two times his or her annual cash retainer. Directors in office as of January 31, 2007 will thus have an ownership goal of $50,000. Directors who join the Board after such date will have an investment goal of two times the annual cash retainer in effect on the date they join the Board. For purposes of this guideline, unvested shares of restricted stock and stock units are counted, but unexercised stock options are not. Directors are expected to achieve this investment goal within three years after the Board’s adoption of these guidelines or the director’s appointment to the Board, whichever is later. Upon meeting the initial investment goal, that number of shares becomes fixed and must be maintained until the end of the director’s service on the Board. A director’s ownership requirement will not change as a result of changes in his or her retainer fee or fluctuations in the Company’s common stock price. Until the investment goal is achieved, the director is required to retain “net gain shares” resulting from the exercise of stock options or the vesting of restricted stock granted under the Company’s equity compensation plans. Net gain shares are the shares remaining after the payment of the option exercise price and taxes owed with respect to the exercise or vesting event (assuming for this purpose a flat 40 percent tax rate).

14. Annual Review

    The Board will engage in an annual self-evaluation. This evaluation will involve the Board as a collective body rather than Directors on an individual basis. The evaluation process will be administered by the Nominating and Corporate Governance Committee, with the results of the evaluation provided to the Board for its consideration.

Board Meetings

1. Scheduling and Selection of Agenda Items for Board Meetings

   To the extent possible, Board meetings should be scheduled well in advance, typically four times per year for a full day. The Chairman and the Secretary are responsible for drafting the agenda for each Board meeting and distributing it in advance to the Directors. Each Board member is encouraged to suggest inclusion of items on the agenda. The Chairman should also consult with each Committee Chair and the Lead Independent Director regarding items appropriate for the Board agenda.

2. Board Material Distributed in Advance

   Information important to the Board’s understanding of matters to be discussed at a Board meeting should be distributed in advance so that Board meeting time may be conserved and the discussion more focused. When appropriate, sensitive subject matters may be discussed at a meeting without advance distribution of written materials to the Board. The Board expects the Chairman and management to provide regularly each Director with information about the Corporation’s business so that the Board may remain fully informed.

3. Director’s Preparation and Participation

   Board members are expected to carefully prepare for, attend and participate in all Board and applicable Committee meetings. Directors are expected to be physically present at meetings. Most Board meetings will be held at the Corporation’s offices in Rockville, Maryland, but may be held elsewhere. Directors’ attendance at meetings via conference telephone, videoconference, or similar communication equipment is discouraged, unless necessary under the circumstances. Each Director is expected to ensure that other existing and planned future commitments will not materially interfere with the member’s service as a Director. Each Director is expected to become familiar with the Corporation’s business and the duties and responsibilities of a director of a publicly-traded company.

4. Management Attendance and Board Access to Management

   Key members of management ordinarily should attend Board meetings. The Board encourages management to schedule employees to present at Board meetings who can provide insight into the items being discussed or should be given exposure to the Board because of their roles in the Corporation’s business. The Board should have complete access to the Corporation’s management.

5. Independent Directors’ Discussion

   It is the Board’s policy to set aside time during each meeting for the independent Directors to meet without any members of management being present. The Lead Independent Director will assume the responsibility of chairing the regularly scheduled meetings of independent Directors and shall bear such further responsibilities which the independent Directors as a whole might designate from time to time.

6. Confidentiality

   The Board believes that maintaining the confidentiality of all information about the Corporation and all deliberations by the Board is imperative.

Committee Matters

1. Board Committees

   The Board currently has three Committees: Audit, Compensation, and Nominating and Corporate Governance. The Board, from time to time, should consider whether to add other Committees, disband a current Committee, add responsibilities to a Committee or reassign responsibilities among Committees.

2. Committee Functions

   The Audit Committee recommends the Corporation’s certified public accountants for approval by the Board, and monitors the effectiveness of the audit effort, the Corporation’s internal financial and accounting organization and controls and financial reporting. The Nominating and Corporate Governance Committee makes recommendations to the Board regarding the size and composition of the Board, establishes procedures for the nomination process, recommends candidates for election to the Board and nominates officers for election by the Board and makes recommendations with respect to corporate governance matters. The Compensation Committee administers the Corporation’s stock option plans, including the review and grant of stock options to all eligible employees under the Corporation’s existing stock option plans, and reviews and approves salaries and other matters relating to compensation of the executive officers of the Corporation.

3. Committee Charters

   The Board has adopted a written charter for each Committee, which should be evaluated periodically by the Committee and the Board.

4. Committee Assignments and Chair

   The Board is responsible for the appointment of individual Directors to the Committees and the appointment of the Chair of each Committee. The Board’s determination will be based on the recommendations of the Nominating and Corporate Governance Committee. Only independent Directors may serve on the Audit, Compensation and Nominating and Corporate Governance Committees. It is the Board’s policy that the position of Chair of each Committee normally should rotate every three to five years and that the composition of each Committee also should be rotated over time.

5. Frequency of Committee Meetings and Committee Agenda

   The Chair of each Committee, in consultation with appropriate members of management, should determine the frequency of Committee meetings and develop the agenda for each meeting. All agendas and minutes of Committee meetings shall be made available to all Directors. Each Committee Chair shall report on the activities of the Committee at each meeting of the full Board. All independent Directors may attend and participate in discussions of any Board Committee, although formal Committee action will only be through the vote of Committee members. Committee meetings will generally be held via conference telephone, videoconference, or similar communication equipment.

6. Resources

   Each Committee shall have access to accountants, compensation consultants, counsel, investment bankers and others whose expertise is deemed by the Committee necessary or appropriate to the Committee’s carrying out its responsibilities.

Management Responsibility and Review

1. Role of Management

   The Board recognizes that it is management’s responsibility to carry out the policies and strategies established by the Board and to carry out the operation of the Corporation’s business. To this end, the Board acknowledges that it should not interfere in management’s discharge of its responsibilities but should provide oversight and encouragement of management.

2. Formal Evaluation of Officers

   The Compensation Committee shall conduct an annual evaluation of all executive and senior officers, including the Chief Executive Officer, in connection with the determination of their compensation and benefits, and, in doing so, shall evaluate the overall effectiveness of the Corporation’s management team. In connection with these evaluations, the Compensation Committee shall seek the views of all Directors, including the Chief Executive Officer, and will share the results of the evaluations with the Board.

3. Evaluation of Chief Executive Officer

   The Chief Executive Officer is expected to report annually to the Compensation Committee on his goals and objectives for the ensuing year and on the degree of achievement of the preceding year’s goals and objectives. All Directors shall be invited to the Compensation Committee meetings where the Chief Executive Officer presents his or her report, and all Directors shall have the opportunity to participate in any follow-up meetings or discussions. In evaluating the Chief Executive Officer, the Board will use both objective and subjective criteria, including but not limited to, the Corporation’s financial performance and accomplishment of the Corporation’s strategic objectives. The Chief Executive Officer shall not attend that portion of any Board or Committee meeting at which his or her evaluation is discussed, except if invited to do so by a vote of the other Directors. The Chair of the Compensation Committee and any other Directors designated by the Chair shall meet with the Chief Executive Officer following completion of the Board’s annual evaluation to discuss the evaluation.

4. Management and Development

   The Chief Executive Officer shall review succession planning and management development with the Nominating and Corporate Governance Committee and the Board, at least annually. In the event of the death, resignation or incapacity of the Chief Executive Officer, the Chairman of the Nominating and Corporate Governance Committee will immediately call a meeting of that committee to recommend to the Board the selection of a temporary or permanent replacement.

5. Board Interaction with Media, Institutional Investors, Press and Others

   The Board believes that management should speak for the Corporation. Individual Directors may meet or otherwise communicate with the Corporation’s various constituencies when appropriate, but only with the knowledge of management, and, in most instances, at the request of management.

Other

1. Implementation and Alteration of these Guidelines

   Implementation of and changes to these guidelines shall be the responsibility of the Nominating and Corporate Governance Committee, working in coordination with the Chairman of the Board and Chief Executive Officer.

2. Annual Review

   The Board will conduct an evaluation of the Board’s effectiveness on at least an annual basis.

3. Disclosure of Guidelines

   These guidelines shall be made available on the Corporation’s website.