XOMA Royalty completes tender offer, acquires Turnstone Biologics for $0.34/share.

XOMA Royalty Corporation has completed its tender offer to acquire all outstanding shares of Turnstone Biologics Corp. for $0.34 in cash plus one non-tradeable contingent value right. A total of 17,192,002 shares were tendered and not withdrawn as of the expiration date.

Emeryville, Calif., July 2, 2025 - XOMA Royalty Corporation (NASDAQ: XOMA), a biotechnology royalty aggregator, has successfully completed its tender offer to acquire all outstanding shares of Turnstone Biologics Corp. (NASDAQ: TSBX) common stock. The offer, which closed on August 7, 2025, provided shareholders with $0.34 in cash per share plus one non-tradeable contingent value right, collectively referred to as the Offer Price.

As of the expiration date, a total of 17,192,002 shares of Turnstone common stock were validly tendered and not withdrawn, representing approximately 74% of the outstanding shares. This met the minimum tender condition and all other conditions set forth in the tender offer. Following the expiration, XOMA Royalty irrevocably accepted the tendered shares and expects to promptly pay for them.

Upon completion of the tender offer, XOMA Royalty merged Turnstone with and into a subsidiary, XRA 3 Corp. (the "Merger"). 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, Turnstone became a wholly owned subsidiary of XOMA Royalty. Prior to the opening of trading on Nasdaq on August 11, 2025, all shares of Turnstone common stock ceased trading, and Turnstone intends to promptly cause such shares to be delisted from Nasdaq and deregistered under the Securities Exchange Act of 1934, as amended.

Advisors to XOMA Royalty included Gibson, Dunn & Crutcher LLP, Leerink Partners as the exclusive financial advisor, and Cooley LLP as legal counsel to Turnstone.

About XOMA Royalty Corporation

XOMA Royalty is a biotechnology royalty aggregator that plays a distinctive role in helping biotech companies achieve their goal of improving human health. The company acquires the potential future economics associated with pre-commercial and commercial therapeutic candidates that have been licensed to pharmaceutical or biotechnology companies. When XOMA Royalty acquires the future economics, the seller receives non-dilutive, non-recourse funding they can use to advance their internal drug candidate(s) or for general corporate purposes. XOMA Royalty has an extensive and growing portfolio of assets, defined as the right to receive potential future economics associated with the advancement of an underlying therapeutic candidate.

For more information about XOMA Royalty and its portfolio, please visit [www.xoma.com](http://www.xoma.com) or follow XOMA Royalty Corporation on LinkedIn.

Forward-Looking Statements

Certain statements contained in this press release are forward-looking statements, including statements regarding the payment and timing of payment of the Offer Price to former Turnstone common stockholders and the ability and timing of delisting of Turnstone’s common stock. These statements are based on assumptions that may not prove accurate, and actual results could differ materially from those anticipated due to certain risks including that XOMA Royalty does not achieve anticipated net cash after winding down Turnstone’s operations, that the timing of the payment or delisting may be delayed, and that there are no payments made under the CVRs. Other potential risks to XOMA Royalty meeting these expectations are described in more detail in XOMA Royalty’s most recent filing on Form 10-Q and in other filings with the Securities and Exchange Commission (“SEC”). Any forward-looking statement in this press release represents XOMA Royalty’s beliefs and assumptions only as of the date of this press release and should not be relied upon as representing its views as of any subsequent date. XOMA Royalty disclaims any obligation to update any forward-looking statement, except as required by applicable law.

References

[1] https://investors.xoma.com/news-events/press-releases/detail/480/xoma-royalty-announces-closing-of-tender-offer-for
[2] https://www.globenewswire.com/news-release/2025/08/11/3130961/7281/en/XOMA-Royalty-Announces-Closing-of-Tender-Offer-for-Turnstone-Biologics.html