[SC 14D9/A] Turnstone Biologics Corp. Amended Tender Offer Recommendation

Rhea-AI Filing Summary

Turnstone Biologics completed a tender offer and merger after the offer expired at 11:59 p.m. ET on August 7, 2025. The Depositary reported 17,192,002 Shares were validly tendered and not withdrawn, representing approximately 74% of outstanding shares, satisfying the minimum condition. Purchaser accepted those Shares for payment and expects to promptly pay the Offer Price of $0.34 cash per share plus one CVR per share. The merger was consummated on August 11, 2025 under Section 251(h) of the DGCL without a stockholder vote. At the effective time, most outstanding Shares were cancelled and converted into the right to receive the Offer Price. Shares ceased trading before the market opened on August 11 and will be delisted, with the Purchaser intending to terminate registration and suspend reporting obligations.

Positive

• Minimum Tender Condition satisfied enabling completion of the transaction
• 17,192,002 Shares tendered, representing approximately 74% of outstanding shares
• Purchaser accepted and will promptly pay for validly tendered shares
• Merger completed under Section 251(h) without need for a stockholder vote

Negative

• Shares ceased trading and will be delisted, eliminating public market liquidity for former Turnstone shares
• Turnstone to suspend Exchange Act reporting, reducing ongoing public disclosures
• Outstanding shares were cancelled and converted into the right to receive the Offer Price
• Minority holders who did not tender may have limited options aside from appraisal rights

Insights

M&A Specialist

Acquirer met tender threshold and closed the merger under DGCL Section 251(h).

The successful tender of approximately 74% of outstanding shares met the Minimum Tender Condition, enabling Purchaser to accept and pay for tendered shares and to complete the merger without a separate stockholder vote. The Offer combined a $0.34 cash component with a non-transferable CVR per share, and Purchaser advised it expects prompt payment. Operationally, this sequence—acceptance following expiration, immediate payment expectation, and a statutory merger under Section 251(h)—is a clean close consistent with control transfers in takeover transactions.

Corporate Governance Expert

Merger completed without a shareholder vote; minority appraisal rights preserved for eligible holders.

Because tendered shares satisfied the threshold, the acquirer consummated the merger pursuant to the Merger Agreement and Section 251(h) of the DGCL, bypassing a shareholder vote. The filing preserves appraisal rights for those who properly demanded them before the Effective Time. Public-company obligations will be curtailed: trading ceased, shares will be delisted, and the Purchaser intends to terminate registration and suspend Turnstone's reporting under the Exchange Act, materially changing public governance and disclosure status.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14D-9

Solicitation/Recommendation Statement

Under Section 14(d)(4) of the Securities Exchange Act of 1934

(Amendment No. 2)

Turnstone Biologics Corp.

(Name of Subject Company)

Turnstone Biologics Corp.

(Name of Persons Filing Statement)

Common Stock, $0.001 par value per share

(Title of Class of Securities)

90042W100

(CUSIP Number of Class of Securities)

Sammy Farah, M.B.A., Ph.D.

President and Chief Executive Officer

Turnstone Biologics Corp.

1110 North Virgil Avenue PMB 94659

Los Angeles, California 90029

(347) 897-5988

(Name, address, and telephone number of person authorized to receive notices and communications

on behalf of the persons filing statement)

With a copy to:

Divakar Gupta

Rama Padmanabhan

Courtney Tygesson

Cooley LLP

55 Hudson Yards

New York, New York 10001

(212) 479-6000

☐ Check the box if the filing relates solely to preliminary communications made before the commencement of a tender offer.

This Amendment No. 2 (this “Amendment”) amends and supplements the Solicitation/Recommendation Statement on Schedule 14D-9 (together with any exhibits attached hereto, as amended or supplemented, this “Schedule 14D-9”) previously filed by Turnstone Biologics Corp., a Delaware corporation (“Turnstone” or the “Company”), with the U.S. Securities and Exchange Commission (the “SEC”) on July 11, 2025, relating to the Tender Offer Statement on Schedule TO filed by XOMA Royalty Corporation, a Nevada corporation (“Purchaser”), with the SEC on July 11, 2025 (together with any exhibits attached thereto, as amended and supplemented, the “Schedule TO”). The Schedule TO relates to the tender offer to acquire all of the outstanding shares of common stock, par value $0.001 per share (“Turnstone Common Stock,” and shares of Turnstone Common Stock, “Shares”), of Turnstone for (A) $0.34 per Share in cash (the “Cash Amount”), payable subject to any applicable tax withholding and without interest, plus (B) one non-transferable contractual contingent value right per Share which represents the right to receive potential payments, in cash, described in, and subject to and in accordance with the terms and conditions of, the Contingent Value Rights Agreement (the “CVR Agreement” and such amount, the “CVR Amount”), subject to any applicable tax withholding and without interest (a “CVR,” and each CVR Amount together with the Cash Amount, the “Offer Price”), all upon the terms and subject to the conditions as set forth in the Offer to Purchase, dated July 11, 2025 (together with any amendments and supplements thereto, the “Offer to Purchase”), and in the related Letter of Transmittal (together with any amendments and supplements thereto, the “Letter of Transmittal,” and together with the Offer to Purchase, the “Offer”).

Except to the extent specifically provided in this Amendment, the information set forth in the Schedule 14D-9 remains unchanged. Capitalized terms used but not otherwise defined in this Amendment shall have the meanings ascribed to them in the Schedule 14D-9. This Amendment is being filed to reflect certain updates as set forth below.

ITEM 8. ADDITIONAL INFORMATION

Item 8 of the Schedule 14D-9 is hereby amended and supplemented by adding a new section captioned “—Expiration of the Offer; Completion of the Merger” on page 31 of the Schedule 14D-9 as follows:

“Expiration of the Offer; Completion of the Merger

At one minute after 11:59 p.m., Eastern time, on August 7, 2025, the Offer and related withdrawal rights expired. The Depositary and Paying Agent advised Purchaser that, as of the expiration of the Offer, a total of 17,192,002 Shares were validly tendered and not validly withdrawn, representing approximately 74% of the Shares outstanding as of the expiration of the Offer.

As of the expiration of the Offer, the number of Shares validly tendered in accordance with the terms of the Offer and not validly withdrawn satisfied the Minimum Tender Condition (as defined in the Merger Agreement) and all other conditions to the Offer were satisfied or waived. Immediately after the expiration of the Offer, Purchaser irrevocably accepted for payment all Shares validly tendered and not validly withdrawn pursuant to the Offer, and Purchaser expects to promptly pay for such Shares.

As a result of its acceptance of the Shares tendered in the Offer, Purchaser acquired sufficient Shares to complete the Merger without the affirmative vote of Turnstone’s stockholders pursuant to Section 251(h) of the DGCL. Accordingly, pursuant to the Merger Agreement, Purchaser completed the acquisition of Turnstone on August 11, 2025 by consummating the Merger pursuant to the Merger Agreement without a vote of Turnstone’s stockholders in accordance with Section 251(h) of the DGCL.

At the Effective Time, each outstanding Share (other than (i) Shares held in the treasury of Turnstone immediately prior to the Effective Time, which will be cancelled without any conversion thereof and no consideration will be delivered in exchange therefor, and (ii) any Shares held by stockholders or owned by beneficial owners who are entitled to demand, and have properly demanded, appraisal of such Shares in accordance with the DGCL and have neither failed to perfect nor effectively withdrawn or lost such rights prior to the Effective Time) was cancelled and converted into the right to receive the Offer Price from Purchaser.

2

Prior to the opening of trading on the Nasdaq Capital Market on August 11, 2025, all Shares ceased trading. Following consummation of the Merger, the Shares will be delisted from the Nasdaq Capital Market. Purchaser intends to take steps to cause the termination of the registration of the Shares under the Exchange Act and suspend all of Turnstone’s reporting obligations under the Exchange Act as promptly as practicable.

On August 11, 2025, Purchaser issued a press release announcing the expiration and results of the Offer and the consummation of the Merger. A copy of the press release is filed as Exhibit (a)(5)(E) hereto and is incorporated herein by reference.”

ITEM 9. EXHIBITS

Item 9 of the Schedule 14D-9 is hereby amended and supplemented by adding the following exhibit:

Exhibit No.		Description
(a)(5)(E)		Press Release of Purchaser, dated August 11, 2025 (incorporated herein by reference to Exhibit (a)(5)(B) to the Schedule TO).

3

SIGNATURE

After due inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Date: August 11, 2025

TURNSTONE BIOLOGICS CORP.
By:		/s/ Sammy Farah
		Sammy Farah
		President and Chief Executive Officer

4

FAQ

What were the results of the tender offer for Turnstone Biologics (TSBX)?

As of the Offer's expiration, 17,192,002 Shares were validly tendered and not withdrawn, representing approximately 74% of outstanding shares.

What did Turnstone shareholders receive in the Offer?

Each accepted Share was converted into the right to receive an Offer Price consisting of $0.34 cash per Share plus one non-transferable CVR per Share, subject to applicable tax withholding.

Did the merger require a stockholder vote?

No. The Purchaser acquired sufficient Shares and completed the merger on August 11, 2025 under Section 251(h) of the DGCL without an affirmative vote of Turnstone's stockholders.

Will Turnstone remain a public company and continue reporting?

No. Trading in Shares ceased prior to market open on August 11, 2025, the Shares will be delisted, and Purchaser intends to seek termination of registration and suspend Turnstone's reporting under the Exchange Act.

Do any shareholders retain rights after the merger?

Shareholders who properly demanded appraisal and preserved those rights prior to the Effective Time are excluded from the automatic conversion and retain appraisal rights under the DGCL.

Is there a press release about the Offer results and merger?

Yes. Purchaser issued a press release announcing the Offer expiration and consummation of the merger on August 11, 2025, filed as Exhibit (a)(5)(E) to this amendment.