Material Agreement, Private Placement (Form 8-K)

Item 1.01. Entry into a Material Definitive Agreement.

On December 23, 2025 (the "EffectiveDate"), Shuttle Pharmaceuticals Holdings, Inc. (the "Company") entered into a First Amendment (the "Amendment") to Asset Purchase Agreement (the "Agreement") with 1563868 B.C. Ltd., a Canadian limited corporation and the Company's wholly owned subsidiary ("Purchaser"), 1542770 BC Ltd., a Canadian limited corporation ("Seller"), and ZhiTian (Andy) Zhang, an individual residing in Vancouver, Canada ("Seller Guarantor"), dated as of November 20, 2025.

Pursuant to the terms and conditions of the Amendment, on the Effective Date, the Company made an accelerated issuance of 320,496 shares of Company Common Stock as payment of a portion of the First Installment Payment (as defined in the Agreement). The Parties agreed that the remaining portion of the First Installment Payment not satisfied by such accelerated issuance would be paid in cash only in accordance with the terms of the Agreement.

The closing of the transactions contemplated under the Amendment were consummated on the Effective Date.

The aggregate number of shares of Company Common Stock issued to Seller on the effective date was 320,496 shares, representing 19.99% of the issued and outstanding shares of Company Common Stock as of the closing date of the Agreement, at a value of $1.76 per share (which value was calculated in accordance with the terms of the Agreement).

The Amendmentcontains customary representations, warranties and covenants that were made solely for the benefit of the parties to the Amendment.

The foregoing description of the Amendment is qualified by reference to the full text of the Amendment, with confidential portions redacted, as applicable, a copy of which is attached as Exhibit 10.1 to this Current Report on Form 8-K and incorporated herein by this reference.

Item 3.02 Unregistered Sales of Equity Securities.

The information set forth under in Item 1.01 of this Current Report on Form 8-K is incorporated herein by reference. The issuance of Company Common Stock, if and when issued pursuant to the terms of the Agreement, will not be registered under the Securities Act and will instead be offered pursuant to the exemption provided in Section 4(a)(2) under the Securities Act and/or Rule 506(b) promulgated thereunder and Rule 903 of Regulation S under the Securities Act.