SCHEDULE 14A INFORMATION

Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934

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Aptevo Therapeutics Inc.

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*** Exercise Your Right to Vote *** Important Notice Regarding the Availability of Proxy Materials for the Stockholder Meeting to Be Held on May 15, 2019. APTEVO THERAPEUTICS INC. APTEVO THERAPEUTICS INC. C/O BROADRIDGE P.O. BOX 1342 BRENTWOOD, NY 11717 Meeting Information Meeting Type: Annual Meeting For holders as of: March 20, 2019 Date: May 15, 2019 Time: 9:00 AM PDT Location: World Trade Center Seattle 2200 Alaskan Way Seattle,WA 98121 You are receiving this communication because you hold shares in the company named above. This is not a ballot. You cannot use this notice to vote these shares. This communication presents only an overview of the more complete proxy materials that are available to you on the Internet. You may view the proxy materials online at www.proxyvote.com or easily request a paper copy (see reverse side). We encourage you to access and review all of the important information contained in the proxy materials before voting. See the reverse side of this notice to obtain proxy materials and voting instructions. E66323-P18810

Before You Vote How to Access the Proxy Materials Proxy Materials Available to VIEW or RECEIVE: ANNUAL REPORT ON FORM 10-K PROXY STATEMENT How to View Online: Have the information that is printed in the box marked by the arrow g XXXX XXXX XXXX XXXX (located on the following page) and visit: www.proxyvote .com. How to Request and Receive a PAPER or E-MAIL Copy: If you want to receive a paper or e-mail copy of these documents, you must request one. There is NO charge for requesting a copy. Please choose one of the following methods to make your request: 1) BY INTERNET: www.proxyvote.com 2) BY TELEPHONE: 1-800-579-1639 3) BY E-MAIL*: sendmaterial@proxyvote.com * If requesting materials by e-mail, please send a blank e-mail with the information that is printed in the box marked by the arrow g XXXX XXXX XXXX XXXX (located on the following page) in the subject line. Requests, instructions and other inquiries sent to this e-mail address will NOT be forwarded to your investment advisor. Please make the request as instructed above on or before May 1, 2019 to facilitate timely delivery. How To Vote Please Choose One of the Following Voting Methods Vote In Person: Many stockholder meetings have attendance requirements including, but not limited to, the possession of an attendance ticket issued by the entity holding the meeting. Please check the meeting materials for any special requirements for meeting attendance. At the meeting, you will need to request a ballot to vote these shares. Vote By Internet: To vote now by Internet, go to www.proxyvote.com. Have the information that is printed in the box marked by the arrow g XXXX XXXX XXXX XXXX (located on the following page) available and follow the instructions. Vote By Mail: You can vote by mail by requesting a paper copy of the materials, which will include a proxy card. E66324-P18810

Voting Items The Board of Directors recommends you vote FOR the following: 1. To elect three nominees to the Board of Directors to hold office for a term expiring at our 2022 Annual Meeting of Stockholders. Nominees: 01) Fuad El-Hibri 02) John E. Niederhuber M.D. 03) Marvin L. White 2. To ratify the selection by the Audit Committee of the Board of Directors of Ernst & Young LLP as the independent registered public accounting firm of the company for the fiscal year ending December 31, 2019. NOTE: Such other business as may properly come before the meeting or any adjournment thereof. E66325-P18810

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