ACHN 2018 Proxy Statement

CORPORATE GOVERNANCE General This section describes key corporate governance guidelines and practices that we have adopted. Complete copies of our corporate governance guidelines, committee charters and Code of Business Conduct and Ethics described below are available on our website at www.achillion.com . Alternatively, you can request a copy of any of these documents by writing to: Investor Relations, Achillion Pharmaceuticals, Inc., 300 George Street, New Haven, Connecticut 06511. Our Board of Directors believes that good corporate governance is important to ensure that we are managed for the long-term benefit of our stockholders. Corporate Governance Guidelines Our Board of Directors adopted corporate governance guidelines to assist the Board of Directors in the exercise of its duties and responsibilities and to serve the best interests of Achillion and our stockholders. These guidelines, which provide a framework for the conduct of the Board’s business, provide that: • the principal responsibility of the directors is to oversee management of the Company; • a majority of the members of the Board of Directors shall be independent directors; • the independent directors meet regularly in executive session; • directors have full and free access to senior executives and, as necessary and appropriate, independent advisors; • new directors participate in an orientation program and all directors are expected to participate in continuing director education on an ongoing basis; and • at least annually, the Board of Directors and its committees will conduct a self-evaluation to determine whether they are functioning effectively. Board of Directors Determination of Independence Under applicable Nasdaq rules, a director only qualifies as an “independent director” if, in the opinion of our Board of Directors, that person does not have a relationship which would interfere with the exercise of independent judgment in carrying out the responsibilities of a director. Our Board of Directors has determined that none of Messrs. Frashier, Graves, Scheer, Kishbauch, or Van Nostrand, Drs. Verwiel or Fisherman, or Ms. Vitullo has a relationship which would interfere with the exercise of independent judgment in carrying out the responsibilities of a director and that each of these directors is an “independent director” as defined under Rule 5605(a)(2) of the Nasdaq Marketplace Rules. Rule 5605 of the Nasdaq Marketplace Rules requires a majority of a listed company’s board of directors to be comprised of independent directors within one year of listing. In addition, the Nasdaq Marketplace Rules require that, subject to specified exceptions, each member of a listed company’s audit, compensation and nominating and corporate governance committees be independent and that audit committee members also satisfy independence criteria set forth in Rule 10A-3 under the Securities Exchange Act of 1934, as amended, or the Exchange Act. Under Rule 5605(a)(2), a director will only qualify as an “independent director” if, in the opinion of our Board of Directors, that person does not have a relationship that would interfere with the exercise of independent judgment in carrying out the responsibilities of a director. In order to be considered independent for purposes of Rule 10A-3, a member of an audit committee of a listed company may not, other than in his or her capacity as a member of the audit committee, the Board of Directors, or any other board committee: (1) accept, directly or indirectly, any consulting, advisory or other compensatory fee from the listed company or any of its subsidiaries; or (2) be an affiliated person of the listed company or any of its subsidiaries. In addition, in affirmatively determining the independence of any director who will serve on a company’s compensation 27