| Key Points: – XOMA will acquire Turnstone for $0.34 per share plus a CVR. – 25.2% of shareholders have agreed to the deal. – The acquisition expands XOMA’s biotech royalty portfolio. |
In a notable development in the biotech investment landscape, XOMA Royalty Corporation has entered into a definitive agreement to acquire Turnstone Biologics Corp. in a cash and contingent value right (CVR) transaction. The acquisition underscores XOMA’s continued push to expand its royalty and milestone-driven portfolio by targeting biotech firms with high-risk, high-reward therapeutic assets.
Under the terms of the deal announced June 27, XOMA Royalty will pay $0.34 per share in cash to Turnstone shareholders, along with a non-transferable CVR tied to future clinical or commercial milestones. The transaction was unanimously approved by Turnstone’s board following a comprehensive strategic review, indicating strong alignment between both companies on the benefits of the proposed merger.
The transaction will be executed through a tender offer, which XOMA is expected to launch by July 11, 2025. To move forward, the offer requires acceptance by holders representing at least a majority of Turnstone’s outstanding shares, along with other standard closing conditions including a minimum cash balance at the time of closing.
Significantly, shareholders representing roughly 25.2% of Turnstone’s stock have already agreed to support the deal and tender their shares, increasing the likelihood of a successful outcome. If the tender offer is completed as planned, remaining shares not tendered—excluding any subject to appraisal rights—will be converted into the same cash and CVR terms. The full acquisition is anticipated to close by August 2025.
The CVR element of the deal provides Turnstone shareholders with potential upside depending on the progress of its pipeline, which historically has focused on Selected Tumor-Infiltrating Lymphocyte (Selected TIL) therapy for the treatment of solid tumors. While the company has faced challenges in recent quarters, its research has positioned it within a promising niche of the immuno-oncology space.
Turnstone has partnered with Leerink Partners as financial advisor and Cooley LLP for legal counsel during the transaction process. On the acquiring side, XOMA is represented by legal firm Gibson, Dunn & Crutcher LLP.
This acquisition adds another layer to XOMA’s unique business model, which focuses on purchasing future economic rights—royalties and milestone payments—from pre-commercial and commercial biotech programs. These rights are typically tied to therapies developed and licensed out by smaller biotech companies to larger pharmaceutical firms. In return, the selling firms receive non-dilutive capital they can reinvest into pipeline development or general operations.
By bringing Turnstone into its fold, XOMA potentially gains exposure to novel cancer therapies while giving Turnstone a viable financial exit at a time when biotech funding remains tight. The CVR component allows existing shareholders to benefit from any future success tied to Turnstone’s core scientific work, creating a hybrid payout structure aligned with both short-term liquidity and long-term optionality.
The transaction reflects a growing trend in biotech M&A, where royalty aggregators like XOMA leverage strategic acquisitions to build long-term value while offering capital relief to development-stage firms.
As of now, both companies remain focused on a smooth closing process, with investors watching closely to see how Turnstone’s science and XOMA’s model will align in the quarters ahead.
