Mustang Bio Files 8-K for Shareholder Vote & Other Events

TL;DR

Mustang Bio is calling for a shareholder vote and has other business updates; details to follow.

AI Summary

Mustang Bio, Inc. filed an 8-K on December 23, 2025, reporting events that occurred on December 17, 2025. The filing indicates that the company is submitting matters to a vote of security holders and also includes other events and financial statements/exhibits. Specific details regarding the vote or the nature of the other events are not provided in this excerpt.

Why It Matters

This filing signals that Mustang Bio is engaging in corporate actions requiring shareholder approval and potentially other significant business developments. Investors should monitor for further details on the nature of these events.

Risk Assessment

Risk Level: medium — The filing indicates corporate actions requiring shareholder approval, which can introduce uncertainty and potential changes in company direction or structure.

Key Players & Entities

• Mustang Bio, Inc. (company) — Registrant
• December 17, 2025 (date) — Earliest event date
• December 23, 2025 (date) — Filing date
• 001-38191 (company) — SEC File Number
• 47-3828760 (company) — IRS Employer Identification No.

FAQ

Key Financial Figures

• $0.0001 — ich registered Common Stock, par value $0.0001 per share MBIO Nasdaq Capital Marke
• $730,000 — i) the Company agreed to pay Fred Hutch $730,000 as consideration for extinguishment of
• $1.4 million — ion for extinguishment of approximately $1.4 million in outstanding payables owing to Fred H

Filing Documents

• tmb-20251217x8k.htm (8-K) — 68KB
• tmb-20251217xex10d1.htm (EX-10.1) — 12KB
• tmb-20251217xex10d2.htm (EX-10.2) — 34KB
• 0001104659-25-124189.txt ( ) — 229KB
• tmb-20251217.xsd (EX-101.SCH) — 3KB
• tmb-20251217_lab.xml (EX-101.LAB) — 15KB
• tmb-20251217_pre.xml (EX-101.PRE) — 10KB
• tmb-20251217x8k_htm.xml (XML) — 5KB

07 Submission of Matters to a Vote of Security Holders

Item 5.07 Submission of Matters to a Vote of Security Holders. Mustang Bio, Inc. ("Mustang" of the "Company") held its 2025 Annual Meeting of stockholders (the "2025 Annual Meeting") on December 22, 2025 by means of an online virtual meeting platform at 9:00 a.m. Eastern Time. At the 2025 Annual Meeting, the following four proposals were approved: (i) the election of seven directors to hold office until the 2026 annual meeting of stockholders; (ii) the ratification of the appointment of KPMG LLP as Mustang's independent registered public accounting firm for the year ending December 31, 2025; (iii) the amendment to the Company's 2019 Employee Stock Purchase Plan (the "ESPP") to increase the number of shares issuable by 250,000 shares and increase the number of shares subject to a Purchase Right thereunder to 10,000; and (iv) the amendment to the Company's 2016 Incentive Plan (the "EIP") to increase the number of shares issuable by Mustang by 2,500,000 shares . The four proposals are described in detail in the Company's 2025 Definitive Proxy Statement on Schedule 14A. As of November 18, 2025, the record date for the determination of the shareholders entitled to notice of, and to vote at, the 2025 Annual Meeting, 6,453,701 shares of the Company's Common Stock were outstanding and eligible to vote with an aggregate of 6,453,701 votes; 845,385 shares of the Company's Class A Common Stock were outstanding and eligible to vote with an aggregate of 1,127 votes; and 250,000 shares of the Company's Class A Preferred Stock were outstanding and eligible to vote with an aggregate of 7,100,677 votes, as determined in accordance with Section 3.1.3 of the Company's Amended and Restated Articles of Incorporation. Approximately 58% of all votes were represented at the 2025 Annual Meeting, constituting a quorum. Proposal 1 The votes with respect to the election of seven directors to hold office until the 2026 annual meeting were as follows: Director For Withheld Broker

01 Other Events

Item 8.01 Other Events As previously disclosed, Mustang Bio, Inc. (the " Company ") previously entered into that certain License Agreement with Fred Hutchinson Cancer Center (" Fred Hutch "), dated as of May 17, 2017 (as amended, the " CD20 License Agreement "), under which the Company developed its CD20 CAR-T program. On December 17, 2025, the Company and Fred Hutch entered into a Termination and Release Agreement, pursuant to which: (i) the Company and Fred Hutch agreed to terminate the CD20 License Agreement; (ii) the Company agreed to pay Fred Hutch $730,000 as consideration for extinguishment of approximately $1.4 million in outstanding payables owing to Fred Hutch; and (iii) the parties agreed that, in the event that Fred Hutch, during the three-year period following execution of the Termination and Release Agreement, grants any third party a license under the CD20 patents or other intellectual property that had been licensed to the Company under the CD20 License Agreement, then Fred Hutch will pay to the Company at least 10% of all consideration received by Fred Hutch from such third party under such licensing arrangement (with an additional obligation to negotiate in good faith for a potentially greater percentage share).

01 Financial Statements and Exhibits

Item 9.01 Financial Statements and Exhibits (d) Exhibits The following exhibits are filed as part of this report: Exhibit No. Description 10.1 Amendment No. 3 to the Mustang Bio, Inc. 2019 Employee Stock Purchase Plan 10.2 Fourth Amendment to the Mustang Bio, Inc., 2016 Incentive Plan 104 Cover Page Interactive Data File (formatted as Inline XBRL)

SIGNATURES

SIGNATURES Pursuant to the requirements of the Securities Exchange Act of 1934, as amended, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. Mustang Bio, Inc. Date: December 23, 2025 By: /s/ Manuel Litchman, M.D. Manuel Litchman, M.D. President, Chief Executive Officer and Interim Chief Financial Officer

View Full Filing

View this 8-K filing on SEC EDGAR