TSBX News & Events

XOMA Royalty announced the Company has completed its previously announced tender offer to acquire all outstanding shares of Turnstone Biologics common stock for a price per share of $0.34 in cash, plus one non-tradeable contingent value right. The tender offer and related withdrawal rights expired one minute after 11:59 p.m. Eastern Time on Thursday, August 7, 2025. As of the Expiration Date, a total of 17,192,002 shares of Turnstone common stock were validly tendered, and not validly withdrawn, representing approximately 74% of the outstanding shares of Turnstone common stock as of the Expiration Date. As of the Expiration Date, the number of shares validly tendered in accordance with the terms of the tender offer and not validly withdrawn satisfied the minimum tender condition, and all other conditions to the tender offer were satisfied or waived. Immediately after the Expiration Date, XOMA Royalty irrevocably accepted for payment all shares validly tendered and not validly withdrawn and expects to promptly pay for such shares. Following the closing of the tender offer, XOMA Royalty merged Turnstone with and into a subsidiary, XRA 3 Corp., and all shares of Turnstone common stock that had not been validly tendered were converted into the right to receive the Offer Price. As a result of the Merger, Turnstone became a wholly owned subsidiary of XOMA Royalty. Prior to the opening of trading on The Nasdaq Stock Market on August 11, 2025, all shares of Turnstone common stock will cease trading on Nasdaq, and Turnstone intends promptly to cause such shares to be delisted from Nasdaq and deregistered under the Securities Exchange Act of 1934, as amended.

XOMA Royalty Corporation (XOMA) and Turnstone Biologics (TSBX) announced that they have entered into a definitive merger agreement, whereby XOMA Royalty will acquire Turnstone for $0.34 in cash per share of Turnstone common stock plus one non-transferable contingent value right. Following a thorough review process conducted with the assistance of its legal and financial advisors, the Turnstone Board of Directors has unanimously determined that the acquisition by XOMA Royalty is in the best interests of all Turnstone stockholders and has approved the Merger Agreement and related transactions. Pursuant and subject to the terms of the Merger Agreement, XOMA Royalty will commence a tender offer by July 11, 2025, to acquire all outstanding shares of Turnstone common stock. Immediately following the closing of the tender offer, Turnstone will be acquired by XOMA Royalty, and all remaining shares not tendered in the offer, other than shares validly subject to appraisal, will be converted into the right to receive the same cash and CVR consideration per share as is provided in the tender offer. Turnstone stockholders holding approximately 25.2% of Turnstone common stock have signed support agreements under which such stockholders have agreed to tender their shares in the Offer and support the merger transaction. The merger transaction is expected to close in August 2025.

Cash, Cash Equivalents and Short-Term Investments: As of December 31, 2024, cash, cash equivalents, and short-term investments were $28.9 million.

Turnstone Biologics has completed an assessment of its business and operations, including the status of its program, resources, and capabilities. The Company has made the determination to discontinue all clinical studies evaluating TIDAL-01 and halt further development of the program. As a result, Turnstone's management and its Board of Directors have initiated a process to explore and review strategic alternatives focused on maximizing shareholder value. Turnstone has engaged a financial advisor to assist in this process, and along with support from its other advisors, intends to explore potential strategic alternatives that may include, but are not limited to, an acquisition, merger, business combination, sale of assets, licensing, or other transactions. Turnstone does not intend to disclose further developments unless and until it is determined that further disclosure is appropriate or legally required. In addition, Turnstone is reducing its workforce while also implementing further cost-containment and cash conservation measures. The Company intends to retain all employees essential for supporting value-realization as part of its strategic review.