Additional Proxy Soliciting Materials - Form DEFA14A

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A INFORMATION

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

(Amendment No. )

Filed by the Registrant ☒

Filed by a Party other than the Registrant ☐

Check the appropriate box:

☐	Preliminary Proxy Statement

☐	Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2))

☐	Definitive Proxy Statement

☒	Definitive Additional Materials

☐	Soliciting Material Pursuant to § 240.14a-12

XBiotech Inc.

(Name of Registrant as Specified In Its Charter)

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☒	No fee required.

☐	Fee paid previously with preliminary materials.

☐	Fee computed on table in exhibit required by Item 25(b) per Exchange Act Rules 14a6(i)(1) and 0-11.

XBiotech Inc. Thursday, June 20,2024 10:00 AM, Central Time Annual Meeting to be held live via the Internet - please visit www.proxydocs.com/XBIT for more details You must register to attend the meeting online and/or partidpate at wvew.proxydocs.com/XBIT For a convenient way to view proxy materials, VOTE, and obtain directions to attend the meeting go to www.proxydocs.com/XBIT 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 shares. We to encourage you on the you Internet. to access This and is notreview a ballot. all ofYou the cannot important use this information notice to contained vote your in the proxy materials before voting. Under United States Securities and Exchange Commission rules, praxy 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 10, 2024. Meeting Materials: Notce of Meeting and Proxy Statement & Annual Reportor Form 10-K To order paper materials, use one of the following methods. g www.investorelections.com/XBIT 1-866-648-8133 [email protected] * tfrequesing material by ermal, please send 2 blank emailwih he 12 digt contol number (located below) in he subject Ine. No other requests, instuctonsOR other inquiries should be incudedwith your email requesting masters Your control number Have the 12 digit control number located in the box above available when you access he website and follow the instructions. SEE REVERSE FOR FULL AGENDA Copyright © 2024 BetaNxT, Inc. or its affiliates. All Rights Reserved

THE BOARD OF DIRECTORS RECOMMENDS A VOTE: FOR ON PROPOSALS 1,2 AND3 XBiotech Inc. Annual Meeting of Stockholders 1. To elect the five (5) nominees for director named herein to serve until the next annual meeting and their successors are duly elected and qualified. 1.01 John Simard 1.02 W. Thorpe McKenzie 1.03 Jan-Paul Waldin, Esq. 1.04 Donald H. MacAdam 1.05 Peter Libby, M.D. 2. To ratify the selection by the Audit Committee of the Board of Directors of Whitley Penn LLP as the independent registered public accounting firm of the Company for its fiscal year ending December 31, 2024. 3. To approve, on an advisory basis, the compensation of the Company's named executive officers. To conduct any other business properly brought before the meeting.