Mural Oncology Announces Agreement to be Acquired by XRA 5 Corp.

Mural Oncology plc and XOMA Royalty Corporation recently announced they have entered into a definitive agreement pursuant to which XRA 5 Corp., a newly formed company wholly owned by XOMA Royalty, has agreed to acquire the entire issued and to be issued share capital of Mural for cash subject to the satisfaction of the closing conditions set out in Appendix I of this Announcement, including approval by Mural Shareholders. Following a strategic review process, the Mural board of directors determined the acquisition and cash offer by XOMA Royalty is in the best interests of all Mural Shareholders and has approved the Acquisition. The Acquisition has also been approved by the boards of directors of XOMA Royalty and Sub.

Under the terms of the Acquisition and subject to certain conditions, at closing, each Mural Shareholder (i) would receive a base cash price of $2.035 per share and (ii) may receive an additional cash amount per share of up to $0.205, which would be calculated on the basis of the amount by which Mural’s Closing Net Cash on the Closing Net Cash Date exceeds its Estimated Closing Net Cash as set out in more detail below and in accordance with the provisions of the transaction agreement entered into between Mural, Sub and XOMA Royalty in respect of the Acquisition, as appended at Appendix IV of this Announcement.

The Base Price Per Share has been calculated on the basis of Mural having approximately $36.2 million in Closing Net Cash on the Closing Net Cash Date, and would be payable to Mural Shareholders on closing of the Acquisition regardless of the actual quantum of Mural’s Closing Net Cash on the Closing Net Cash Date. The Additional Price Per Share is intended to return any Excess Cash to Mural Shareholders. As a result, the Additional Price Per Share would only be payable to Mural Shareholders on closing of the Acquisition if Mural’s Closing Net Cash on the Closing Net Cash Date exceeds the Estimated Closing Net Cash. There is no certainty that Mural’s Closing Net Cash on the Closing Net Cash Date will exceed the Estimated Closing Net Cash and, if Mural’s Closing Net Cash does not the exceed Estimated Closing Net Cash, the amount of the Additional Price Per Share will be zero and each Mural Shareholder would receive only the Base Price Per Share.

The Additional Price Per Share is subject to a cap of a maximum amount of $0.205 per share.

The Acquisition, excluding any amount that may be payable in respect of the Additional Price Per Share, values the entire issued and to be issued share capital of Mural at approximately $36.2 million.

Excluding any Additional Price Per Share which may be payable as described above, the Acquisition represents a:

• premium of approximately 13.1% to Mural’s closing share price of $1.80 on August 19, 2025, being the Business Day immediately before the date on which this Announcement has been released; and
• premium of approximately 97.6% to Mural’s undisturbed closing share price of $1.03 on April 14, 2025 (being the last Business Day prior to the announcement of the commencement of the strategic review by the Mural Board on April 15, 2025).

Capitalised terms used in this Announcement and not otherwise defined have the meaning given to them in Appendix I.

Caroline Loew, PhD, Chief Executive Officer of Mural, said “The Transaction Agreement with XOMA Royalty announced today is the result of a thorough and wide-ranging strategic review process, conducted with the support of our legal and financial advisors. We believe that this transaction, which is supported by our Board, achieves the goal of this strategic review process, which was to maximize shareholder value.”

Owen Hughes, Chief Executive Officer of XOMA Royalty, added “XOMA Royalty looks forward to working with Mural to close the transaction as soon as possible.”

The Mural Directors, who hold Mural Shares representing, in aggregate, approximately 0.42% of Mural’s outstanding ordinary shares, Mural RSUs representing, in aggregate, approximately 1.27% of Mural’s outstanding ordinary shares and options to acquire Mural Shares representing, in aggregate, approximately 4.32% of Mural’s outstanding ordinary shares have entered into irrevocable undertakings to vote in favor of the Acquisition. All outstanding options to acquire Mural Shares held by the Mural Directors have a strike price above the maximum Consideration payable pursuant to the Acquisition and will be cancelled without the right to receive any Consideration in accordance with the terms of the Transaction Agreement.

Having taken into account the relevant factors, applicable risks and alternatives available to Mural, the Mural Board, which has been so advised by Lucid Capital Markets, LLC, as financial adviser and Rule 3 adviser to Mural, as to the financial terms of the Acquisition, considers the terms of the Acquisition as set out in this Announcement to be fair and reasonable. Accordingly, the Mural Board intends to recommend that Mural Shareholders vote in favor of the Acquisition.

It is intended that the Acquisition will be implemented by means of a High Court sanctioned scheme of arrangement under Chapter 1 of Part 9 of the Irish Companies Act (or, if Sub elects, subject to the terms of the Transaction Agreement, compliance with the Irish Takeover Rules and with the consent of the Irish Takeover Panel, a Takeover Offer). The Acquisition is expected to close by the end of 2025, subject to the satisfaction of the Conditions, which include (i) the approval by Mural Shareholders of the Scheme Meeting Resolution and the Required EGM Resolutions; and (ii) the sanction of the Scheme by the High Court.

The Scheme Document, which will contain, among other things, further information about the Acquisition, notices convening the Scheme Meeting and the Extraordinary General Meeting, the expected timetable for completion of the Acquisition and action to be taken by Mural Shareholders, will be published as soon as practicable following this Announcement. The Scheme Document will be included within the Proxy Statement to be filed by Mural with the U.S. Securities and Exchange Commission and sent to Mural shareholders as of the record date(s) to be established for voting at the Scheme Meeting and EGM in respect of the Acquisition.

XOMA Royalty Corporation is a biotechnology royalty aggregator playing a distinctive role in helping biotech companies achieve their goal of improving human health. XOMA Royalty 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 (asset defined as the right to receive potential future economics associated with the advancement of an underlying therapeutic candidate). XOMA Royalty has its corporate headquarters in Emeryville, CA. For more information, visit www.xoma.com.

XRA 5 Corp. is a Delaware corporation established for the sole purpose of implementing the Acquisition. As of the date of this Announcement, the entire issued and outstanding shares of capital stock of Sub are directly owned by XOMA Royalty.

Mural Oncology plc is a biotechnology company focused on using its protein engineering platform to develop cytokine-based immunotherapies for the treatment of cancer with the goal of delivering meaningful and clinical benefits to people living with cancer. On March 25, 2025, Mural announced that, based on the interim analysis of results, its Phase 3 ARTISTRY-7 trial of nemvaleukin alfa (nemvaleukin) in combination with pembrolizumab did not achieve its primary endpoint of a statistically significant improvement in overall survival versus investigator’s choice chemotherapy. Mural also announced that ARTISTRY-7 would not continue to final analysis and Mural would cease development of nemvaleukin for platinum resistant ovarian cancer. On April 15, 2025, Mural announced that following review of data from its Phase 2 ARTISTRY-6 trial of nemvaleukin in mucosal and cutaneous melanoma and the previously announced results from the ARTISTRY-7 trial, Mural was discontinuing all clinical development of nemvaleukin and planned to immediately commence an exploration of strategic alternatives focused on maximizing shareholder value. Mural has its registered office in Dublin, Ireland, and its primary facilities in Waltham, MA. For more information, visit www.muraloncology.com.