Tempest Therapeutics (TPST) DEFA14A Additional proxy soliciting materials

United States

Securities and Exchange Commission

Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of the

Securities Exchange Act of 1934

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☐ 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 under § 240.14a-12

Tempest 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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Your Vote Counts! TEMPEST THERAPEUTICS, INC. 2022 Annual Meeting Vote by June 16, 2022 11:59 PM ET TEMPEST THERAPEUTICS, INC. 7000 SHORELINE COURT SUITE 275 SOUTH SAN FRANCISCO, CA 94080 D84018-P69217 You invested in TEMPEST THERAPEUTICS, INC. and it’s time to vote! You have the right to vote on proposals being presented at the Annual Meeting. This is an important notice regarding the availability of proxy material for the stockholder meeting to be held on June 17, 2022. Get informed before you vote View the Notice and Proxy Statement and Form 10-K online OR you can receive a free paper or email copy of the material(s) by requesting prior to June 3, 2022. If you would like to request a copy of the material(s) for this and/or future stockholder meetings, you may (1) visit www.ProxyVote.com, (2) call 1-800-579-1639 or (3) send an email to sendmaterial@proxyvote.com. If sending an email, please include your control number (indicated below) in the subject line. Unless requested, you will not otherwise receive a paper or email copy. For complete information and to vote, visit www.ProxyVote.com Control # Smartphone users Vote Virtually at the Meeting* Point your camera here and June 17, 2022 1:00 P.M. Pacific Time vote without entering a control number Virtually at: www.virtualshareholdermeeting.com/TPST2022 *Please check the meeting materials for any special requirements for meeting attendance.

Vote at www.ProxyVote.com THIS IS NOT A VOTABLE BALLOT This is an overview of the proposals being presented at the upcoming stockholder meeting. Please follow the instructions on the reverse side to vote these important matters. Voting Items Board Recommends 1. Election of Director Nominee: 1a. Geoff Nichol For 2. To approve the Amended and Restated 2019 Equity Incentive Plan. For 3. To approve the Amended and Restated 2019 Employee Stock Purchase Plan. For 4. To ratify the appointment of Ernst & Young LLP as the Company’s independent registered public accounting firm for For the fiscal year ending December 31, 2022. NOTE: Such other business as may properly come before the meeting or any adjournment thereof. Prefer to receive an email instead? While voting on www.ProxyVote.com, be sure to click “Sign up for E-delivery”.