DEFA14A

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
SCHEDULE 14A
(Rule 14a-101)

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

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☐ Preliminary Proxy Statement

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☐ Definitive Proxy Statement

☒ Definitive Additional Materials

☐ Soliciting Material under §240.14a-12

Acrivon Therapeutics, Inc.

(Name of Registrant as Specified In Its Charter)

(Name of Person(s) Filing Proxy Statement, if other Than the Registrant)

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26. 3. The transaction of such other business as may properly come before the meeting.

P.O. BOX 8016, CARY, NC 27512-9903 Your vote Acrivon Therapeutics, Inc. Annual Meeting of Stockholders Wednesday, June 17, 2026 1:00 PM, Eastern Time Annual meeting to be held virtually via the internet - please visit www.proxypush.com/ACRV for more details. You must register to attend the meeting online and/or participate at www.proxydocs.com/ACRV For a convenient way to view proxy materials, VOTE, and obtain directions to attend the meeting go to www.proxydocs.com/ACRV To vote your proxy while visiting this site, you will need the 12 digit control number in the box below. This communication presents only an overview of the more complete proxy materials that are available to you on the Internet. This is not a ballot. You cannot use this notice to vote your shares. We encourage you to access and review all of the important information contained in the proxy materials before voting. Under United States Securities and Exchange Commission rules, proxy materials do not have to be delivered in paper. Proxy materials can be distributed by making them available on the internet. If you want to receive a paper or e-mail copy of the proxy material, you must request one. There is no charge to you for requesting a copy. In order to receive a paper package in time for this year's meeting, you must make this request on or before June 5, 2026. Meeting Materials: Notice of Meeting and Proxy Statement & Annual Report on Form 10-K Important Notice Regarding the Availability of Proxy Materials for the Stockholders Meeting To Be Held On June 17, 2026 For Stockholders of record as of April 23, 2026 To order paper materials, use one of the following methods. To receive paper materials, you must make this request on or before June 5, 2026. Internet: www.investorelections.com/ACRV Call: 1-866-648-8133 Email: paper@investorelections.com * If requesting material by e-mail, please send a blank e-mail with the 12 digit control number (located below) in the subject line. No other requests, instructions OR other inquiries should be included with your e-mail requesting material. Have the 12 digit control number located in the box above available when you access the website and follow the instructions.SEE REVERSE FOR FULL AGENDA Copyright 2026 BetaNXT, Inc. or its affiliates. All Rights Reserved

Acrivon Therapeutics, Inc. Annual Meeting of Stockholders THE BOARD OF DIRECTORS RECOMMENDS A VOTE: FOR ALL DIRECTOR NOMINEES AND FOR PROPOSAL 2 1. Election of Class I directors 1.01 Michael Tomsicek, M.B.A. 1.02 Charles Baum, M.D., Ph.D. 2. To ratify the appointment of PricewaterhouseCoopers LLP as independent registered public accounting firm for the fiscal year ending December 31, 2026. 3. The transaction of such other business as may properly come before the meeting.

SEC Form DEFA14A filed by Acrivon Therapeutics Inc.