野马生物美股招股说明书(2025-04-01版)

495,000 Shares of Common Stock 2,162,807 Pre-funded Warrants to Purchase up to 2,162,807 Shares of Common Stock2,657,807 Series C-1 Warrants to Purchase up to 2,657,807 Shares of Common Stock2,657,807 Series C-2 Warrants to Purchase up to 2,657,807 Shares of Common Stock Placement Agent Warrants to Purchase up to 159,468 Shares of Common Stock Up to 7,637,889 Shares of Common Stock Issuable Upon Exercise ofthe Series C-1 Warrants, Series C-2 Warrants, Pre-funded Warrants and Placement Agent Warrants This prospectus supplement is being filed to update and supplement the information contained in the prospectus dated February 5,2025 (as further supplemented or amended from time to time, the “Prospectus”), with the information contained in our Annual Reporton Form 10-K filed with the Securities and Exchange Commission (the “SEC”) on March 28, 2025. Accordingly, we have attachedsuch report to this prospectus supplement. The Prospectus and this prospectus supplement relate to the offer and sale by us of an aggregate of (i) 495,000 shares of commonstock, par value $0.0001 per share, (ii) pre-funded warrants (the “Pre-Funded Warrants”) to purchase up to an aggregate of 2,162,807shares of common stock (the “Pre-Funded Warrant Shares”), (iii) Series C-1 warrants (the “Series C-1 Warrants”) to purchase up to anaggregate of 2,657,807 shares of common stock (the “Series C-1 Warrant Shares”), and (iv) Series C-2 warrants (the “Series C-2Warrants,” and together with the Series C-1 Warrants, the “Warrants”) to purchase up to an aggregate of 2,657,807 shares of commonstock (the “Series C-2 Warrant Shares,” and together with the Series C-1 Warrant Shares, the “Warrant Shares”). The Prospectus andthis prospectus supplement also relate to the offering of the shares of common stock issuable upon exercise of the Warrants, Pre-Funded Warrants and placement agent warrants we issued to H.C. Wainwright & Co. LLC, as placement agent, to purchase up to159,468 shares of our common stock. This prospectus supplement updates and supplements the information in the Prospectus and is not complete without, and may not bedelivered or utilized except in combination with, the Prospectus, including any amendments or supplements thereto. This prospectussupplement should be read in conjunction with the Prospectus and if there is any inconsistency between the information in theProspectus and this prospectus supplement, you should rely on the information in this prospectus supplement. Our common stock is listed on the Nasdaq Capital Market under the symbol “MBIO”. On March 28, 2025, the last reported sale priceof our common stock on the Nasdaq Capital Market was $1.33 per share. Investing in our securities involves risks that are described in the “Risk Factors” section beginning on page 14 of theProspectus. Neither the SEC nor any state securities commission has approved or disapproved of thesecurities to be issuedunderthe Prospectus or determined if the Prospectus or this prospectus supplement is truthful or complete. Anyrepresentation to the contrary is a criminal offense. The date of this prospectus supplement is April 1, 2025 UNITED STATESSECURITIES AND EXCHANGE COMMISSIONWashington, D.C. 20549 FORM10-K ☒ANNUAL REPORT PURSUANT TO SECTION13 OR 15(d)OF THE SECURITIES EXCHANGE ACT OF 1934 For the FiscalYear Ended December 31, 2024 or Commission File No.001-38191 Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule405 of the Securities Act. Yes◻No⌧ Indicate by check mark if the registrant is not required to file reports pursuant to Section13 or Section15(d)of the Act. Yes◻No⌧ Indicate by check mark whether the registrant (1)has filed all reports required to be filed by Section13 or 15(d)of the SecuritiesExchange Act of 1934 during the preceding 12months (or for such shorter period that the registrant was required to file such reports),and (2)has been subject to such filing requirements for the past 90days. Yes⌧No◻ Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submittedpursuant to Rule405 of Regulation S-T (§232.405 of this chapter) during the preceding 12months (or for such shorter period that theregistrant was required to submit such files). Yes⌧No◻ Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, smaller reportingcompany, or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growth company” in Rule12b-2 of the Exchange Act: Largeacceleratedfiler◻Non-accelerated filer☒Emerging growth company☐ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period forcomplying with any new or revised financial accounting standards provided pursuant to Section13(a)of the Exchange Act.◻ Indicate by check