APELLIS PHARMACEUTICALS, INC. 6400 Westwind Way, Suite A, Crestwood, Kentucky 40014 (502) 241-4114 NOTICE OF 2018 ANNUAL MEETING OF STOCKHOLDERS To Be Held on June 4, 2018 Dear Stockholders: You are cordially invited to attend the 2018 annual meeting of stockholders, or the Annual Meeting, of Apellis Pharmaceuticals, Inc. which is scheduled to be held on Monday, June 4, 2018 at 11:00 a.m., Eastern time, at the offices of Wilmer Cutler Pickering Hale and Dorr LLP located at 60 State Street, Boston, Massachusetts 02109. Only stockholders who owned shares of our common stock at the close of business on April 10, 2018 can vote at the Annual Meeting or any adjournment that may take place. At the Annual Meeting, the stockholders will consider and vote on the following matters: 1. Election of one Class I director to hold office until the 2021 annual meeting of stockholders; 2. Ratification of the appointment of Ernst & Young LLP as our independent registered public accounting firm for the fiscal year ending December 31, 2018; and 3. Transaction of any other business that may properly come before the Annual Meeting or any adjournment or postponement of thereof. You can find more information, including the nominees for director, in the proxy statement for the Annual Meeting, which is available for viewing, printing and downloading at https://www.proxydocs.com/APLS. The board of directors recommends that you vote in favor of each of proposals one and two as outlined in the attached proxy statement. Instead of mailing a paper copy of our proxy materials to all of our stockholders, we are providing access to our proxy materials via the Internet under the “notice and access” rules of the Securities and Exchange Commission. As a result, we are sending to our stockholders a Notice of Internet Availability of Proxy Materials, or the Notice, instead of a paper copy of this proxy statement and our annual report for the fiscal year ended December 31, 2017, or the 2017 Annual Report. We plan to mail the Notice on or about April 27, 2018, and the Notice contains instructions on how to access our proxy materials over the Internet. The Notice also contains instructions on how each of our stockholders can receive a paper copy of our proxy materials, including the proxy statement, our 2017 Annual Report, and a form of proxy card. We cordially invite all stockholders to attend the Annual Meeting in person. Stockholders of record at the close of business on April 10, 2018, the record date for the Annual Meeting, are entitled to notice of, and to vote at, the Annual Meeting or any adjournment or postponement of the Annual Meeting. Whether or not you expect to attend the Annual Meeting in person, please vote your shares to ensure your representation and the presence of a quorum at the Annual Meeting. If you are a stockholder of record, you may vote your shares on the Internet by visiting https://www.proxypush.com/APLS , by telephone by calling 866-362-4346 and following the recorded instructions or by completing, signing, dating, and returning a proxy card. Your vote is important regardless of the number of shares you own. If you mail your proxy card or vote by telephone or the Internet and then decide to attend the Annual Meeting to vote your shares in person, you may still do so. Your proxy is revocable in accordance with the procedures set forth in the proxy statement.