and Exhibit 99.1 incorporated herein shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”) or otherwise subject to the liabilities of that section, nor shall such information or Exhibit 99.1 be deemed to be incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

Entry into a Material Definitive Agreement. Underwritten Public Offering On June 9, 2026, Shattuck Labs, Inc. (the “Company”) entered into an underwriting agreement (“Underwriting Agreement”) with Leerink Partners LLC, J.P. Morgan Securities LLC, Piper Sandler & Co. and Cantor Fitzgerald & Co., as the representatives of the underwriters named therein (the “Underwriters”), relating to the offering, issuance and sale of 10,879,376 shares of the Company’s common stock, par value $0.0001 per shar…

The filing pertains to an equity incentive plan amendment and restatement, not a management change.

and Exhibit 99.1 incorporated herein shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”) or otherwise subject to the liabilities of that section, nor shall such information or Exhibit 99.1 be deemed to be incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

and Exhibit 99.1 incorporated herein shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”) or otherwise subject to the liabilities of that section, nor shall such information or Exhibit 99.1 be deemed to be incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

Entry into a Material Definitive Agreement. On January 22, 2026, Shattuck Labs, Inc. (the “Company”) entered into a sales agreement (the “Sales Agreement”) with Leerink Partners LLC (the “Agent”), pursuant to which the Company may offer and sell from time to time shares of the Company’s common stock, $0.0001 par value per share (the “Shares”), through the Agent. The offering and sale of up to $75,000,000 of the Shares has been registered under the Securities Act of 1933, as amended (the “Secu…

and Exhibit 99.1 incorporated herein shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”) or otherwise subject to the liabilities of that section, nor shall such information or Exhibit 99.1 be deemed to be incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

and Exhibit 99.1 incorporated herein shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”) or otherwise subject to the liabilities of that section, nor shall such information or Exhibit 99.1 be deemed to be incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

Director — Tyler Brous, Dr. Carrie Brownstein, Michael Lee, Dr. Kate Sasser: Four directors resigned from the Board of Directors as part of a significant corporate transaction.

and Exhibit 99.1 incorporated herein shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”) or otherwise subject to the liabilities of that section, nor shall such information or Exhibit 99.1 be deemed to be incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

Based in part upon the representations of the Purchasers in the Securities Purchase Agreement, the offering and sale of the securities will be made in reliance on the exemption afforded by Section 4(a)(2) of the Securities Act of 1933, as amended (the “ Securities Act ”), and/or Regulation D thereunder, and corresponding provisions of state securities or “blue sky” laws. The securities will not be registered under the Securities Act or any state securities laws and may not be offered or sold…

Entry Into a Material Agreement. Securities Purchase Agreement On August 4, 2025, Shattuck Labs, Inc., a Delaware corporation (the “ Company ”), entered into a securities purchase agreement (the “ Securities Purchase Agreement ”) with certain institutional accredited investors named therein (each, a “ Purchaser ” and collectively, the “ Purchasers ”), pursuant to which the Company agreed to issue and sell to the Purchasers in a private placement (the “ Private Placement ”) an aggregate of 15,…

and Exhibit 99.1 incorporated herein shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”) or otherwise subject to the liabilities of that section, nor shall such information or Exhibit 99.1 be deemed to be incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

and Exhibit 99.1 incorporated herein shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”) or otherwise subject to the liabilities of that section, nor shall such information or Exhibit 99.1 be deemed to be incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

and Exhibit 99.1 incorporated herein shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”) or otherwise subject to the liabilities of that section, nor shall such information or Exhibit 99.1 be deemed to be incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

Termination of a Material Definitive Agreement. On September 30, 2024, Shattuck Labs, Inc. (the “Company”) and Ono Pharmaceutical Co., Ltd. (“Ono”) mutually agreed to terminate the Collaboration and License Agreement dated February 13, 2024 (the “Collaboration Agreement”). Under the Collaboration Agreement, Ono and the Company were collaborating on preclinical development of certain compounds. Following the mutual termination, the Company is no longer required to satisfy any remaining perform…

Other Events. On October 1, 2024, the Company issued a press release announcing that it was discontinuing clinical development of SL-172154 and implementing the restructuring described above under

Costs Associated with Exit or Disposal Activities. On October 1, 2024, pursuant to previous authorization by the Board of Directors of the Company, an authorized officer of the Company approved a restructuring plan to prioritize the development of the Company’s DR3 program. The plan is intended to optimize the Company’s cost structure by aligning the size and structure of its workforce with the Company’s current goals and strategy. The organizational realignment includes discontinuing the Com…

and Exhibit 99.1 incorporated herein shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”) or otherwise subject to the liabilities of that section, nor shall such information or Exhibit 99.1 be deemed to be incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

Director — Drs. Kate Sasser and Clay Siegall: Dr. Sasser was appointed to the Nominating and Corporate Governance Committee, and Dr. Siegall was appointed to the Compensation Committee.

and Exhibit 99.1 incorporated herein shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”) or otherwise subject to the liabilities of that section, nor shall such information or Exhibit 99.1 be deemed to be incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

Director — Dr. Kate Sasser, Dr. Clay Siegall: The Board of Directors expanded its size and appointed two new directors.

and Exhibit 99.1 incorporated herein shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”) or otherwise subject to the liabilities of that section, nor shall such information or Exhibit 99.1 be deemed to be incorporated by reference in any filing under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such a filing.

Entry into a Material Definitive Agreement. On February 9, 2024, Shattuck Labs, Inc. (“Shattuck”) entered into a collaboration and license agreement (the “Collaboration Agreement”) with Ono Pharmaceutical Co., Ltd (“Ono”), effective February 13, 2024, pursuant to which Shattuck and Ono will collaborate in the research and preclinical development of certain prespecified compounds directed toward a pair of targets selected by Ono from Shattuck’s pipeline of bifunctional fusion proteins (the “De…

Unregistered Sales of Equity Securities. To the extent required by Form 8-K, the disclosures in