Welcome to our dedicated page for Turnstone Biologics SEC filings (Ticker: TSBX), a comprehensive resource for investors and traders seeking official regulatory documents including 10-K annual reports, 10-Q quarterly earnings, 8-K material events, and insider trading forms.
The TSBX SEC filings page on Stock Titan aggregates the historical regulatory filings of Turnstone Biologics Corp., which traded under the TSBX ticker before becoming a wholly owned subsidiary of XOMA Royalty Corporation and delisting from The Nasdaq Capital Market. These documents provide a detailed record of Turnstone’s operations as a clinical-stage biotechnology company focused on Selected tumor‑infiltrating lymphocyte (Selected TIL) therapy for solid tumors.
Through this page, users can access annual reports on Form 10‑K and quarterly reports on Form 10‑Q that describe Turnstone’s research and development activities, general and administrative expenses, net losses, risk factors, and discussion of its clinical programs such as TIDAL‑01. These filings offer insight into the company’s strategy, its focus on microsatellite stable colorectal cancer and other solid tumors, and the financial profile typical of a clinical-stage biotech.
The filings set also includes multiple current reports on Form 8‑K documenting material events. Examples include announcements of positive initial data from the Phase 1 STARLING trial, strategic restructuring and workforce reductions, the decision to discontinue all TIDAL‑01 clinical studies and explore strategic alternatives, and the Agreement and Plan of Merger with XOMA Royalty Corporation. Later 8‑K and 8‑K/A filings detail the tender offer, completion of the merger, change in control, and amendments to Turnstone’s charter and bylaws.
For trading and registration status, users can review the Form 25 filed by Nasdaq on August 11, 2025, which notifies the removal of Turnstone’s common stock from listing and/or registration on Nasdaq, and the Form 15 filed by Turnstone Biologics Corp. on August 21, 2025, certifying termination of registration of its common stock under Section 12(g) of the Exchange Act and suspension of reporting obligations under Sections 13 and 15(d). Together, these documents confirm that TSBX is a delisted and deregistered security.
Stock Titan’s platform surfaces these filings with AI-powered summaries that highlight key points from lengthy reports, helping users quickly understand clinical program disclosures, restructuring steps, merger terms, and changes in listing status. Real-time connections to the SEC’s EDGAR system ensure that historical updates are captured as filed, while structured access to Forms 10‑K, 10‑Q, 8‑K, 25, and 15 allows investors and researchers to trace the full regulatory history of Turnstone Biologics under the TSBX symbol.
Turnstone Biologics (TSBX) director Jerel Davis reported the disposition of a total of 3,381,692 common shares, shown as held indirectly through five Versant-managed funds, in connection with a merger/tender offer. The transactions are described as dispositions pursuant to an Agreement and Plan of Merger under which XOMA Royalty Corporation paid $0.34 per share in cash plus one non-transferable contractual contingent value right (CVR) per share. The Form 4 lists each fund-level holding and shows zero beneficial ownership remaining for the affected holdings following the reported transactions.
Turnstone Biologics director Rishi Gupta reported a disposition of common stock on 08/08/2025 pursuant to an Agreement and Plan of Merger dated June 26, 2025, under which XOMA Royalty Corporation completed a cash tender offer. The tender paid $0.34 per share in cash and one non-transferable contingent value right (CVR) per share.
The filing identifies that these securities are held of record by OrbiMed Private Investments VI, LP, with OrbiMed Capital GP VI LLC as general partner and OrbiMed Advisors LLC as managing member; the reporting person is an employee of OrbiMed Advisors. The report shows 3,099,265 shares beneficially owned following the reported transaction and disclaims beneficial ownership except to the extent of any pecuniary interest. The disposition occurred pursuant to the merger terms rather than as an open-market sale.
Turnstone Biologics Corp. (TSBX) filed an 8-K announcing a definitive merger agreement with XOMA Royalty Corporation. Under the Agreement and Plan of Merger signed 26 June 2025, XOMA will launch a cash tender offer for 100 % of Turnstone’s common stock at $0.34 per share in cash plus one contingent value right (CVR). The CVR entitles holders to share in potential cash receipts of: (i) up to $1.11 million tied to tax-receivable and lease-deposit contingencies, (ii) any Net Cash Excess, and (iii) less any Net Cash Shortfall, but only if such proceeds are received within one year of closing. The CVR is non-transferable, non-voting and carries no interest.
The Board unanimously determined the transaction is fair and recommends shareholders tender. Key closing conditions include: (1) more than 50 % of outstanding shares validly tendered, (2) no legal restraints, (3) accuracy of reps & warranties, (4) material covenant compliance, and (5) satisfaction of a stipulated Closing Net Cash threshold (exact amount not disclosed in the filing). The deal is not subject to a financing condition.
Following successful completion of the tender, Merger Sub will be merged into Turnstone using DGCL §251(h), making Turnstone a wholly-owned subsidiary of XOMA without further shareholder approval. All outstanding stock options will be cancelled for no consideration. Restricted stock units will vest, then convert into the same cash-plus-CVR consideration as common shares.
Approximately 25 % of outstanding shares are already committed through Support Agreements signed with certain shareholders. Termination provisions include a $350 k break-fee payable by Turnstone if it accepts a superior proposal, and expense reimbursement of up to $350 k payable to XOMA if the Closing Net Cash condition is not met. The offer must launch within 10 business days and, if not closed by 26 Oct 2025, either party may terminate.
Turnstone Biologics Corp (TSBX) has filed a Schedule 14D-9 in response to a proposed acquisition by XOMA Royalty Corporation. The filing, dated June 28, 2025, relates to preliminary communications made before the commencement of a tender offer and includes a press release dated June 27, 2025.
Key details of the transaction:
- The acquisition will be executed through a merger agreement dated June 26, 2025
- XRA 3 Corp, a wholly-owned subsidiary of XOMA, will be the merger vehicle
- The target securities are Common Stock with $0.001 par value per share (CUSIP: 90042W100)
The filing indicates preliminary stage communications, with Sammy Farah, President and CEO of Turnstone Biologics, serving as the authorized representative. Legal counsel is being provided by Cooley LLP. This Schedule 14D-9 represents an important step in the merger process, signaling potential changes in ownership and control of Turnstone Biologics.
XOMA Royalty Corporation has announced plans to commence a tender offer to acquire all outstanding shares of Turnstone Biologics (TSBX), pursuant to a Merger Agreement dated June 26, 2025. This SC TO-C filing represents preliminary communications before the formal tender offer launch.
Key aspects of the transaction:
- XOMA will acquire all issued and outstanding common shares of Turnstone (par value $0.001)
- The deal includes a Contingent Value Rights (CVR) Agreement for potential additional payments to Turnstone stockholders
- Transaction will be executed through XRA 3 Corp, a wholly-owned subsidiary of XOMA
The formal tender offer has not yet commenced. When initiated, XOMA will file a Schedule TO with the SEC, and Turnstone will file a Schedule 14D-9 with their recommendation. Shareholders are advised to review the complete tender offer materials once available through the SEC website or XOMA's investor relations portal.