SAB 生物制药公司美股招股说明书（2026年3月19日版）

We are offering 19,324,677 shares of our common stock, par value $0.0001 per share (“common stock”), and, in lieu of shares ofcommon stock to investors that so choose, pre-funded warrants to purchase up to 2,753,246 shares of our common stock (the “pre-funded warrants”) (and the shares of common stock issuable from time to time upon exercise of the pre-funded warrants), pursuantto this prospectus supplement and the accompanying prospectus. The pre-funded warrants will be exercisable immediately and areexercisable for one share of our common stock. The purchase price of each pre-funded warrant is equal to the purchase price at Our common stock is listed on The Nasdaq Capital Market under the symbol “SABS”. On March 17, 2026, the last reported saleprice for our common stock on The Nasdaq Capital Market was $4.07 per share. There is no established public trading market forthe pre-funded warrants, and we do not expect a market to develop. In addition, we do not intend to apply for listing of the pre- We are an “emerging growth company” as defined in Section 2(a) of the Securities Act of 1933, as amended (the “Securities Act”),and a “smaller reporting company” as defined under Rule 405 of the Securities Act, and as such, we have elected to comply withcertain reduced public company reporting requirements. See “Prospectus Supplement Summary— Implications of Being an Investing in our securities involves a high degree of risk. Please read the section titled “Risk Factors” beginning on page S-9of this prospectus supplement, page 7 of the accompanying prospectus, and in the documents incorporated by reference into Neither the Securities and Exchange Commission nor any state securities commission has approved of anyone's investmentin these securities or determined if this prospectus supplement is truthful or complete. Any representation to the contrary is Delivery of the shares of common stock and pre-funded warrants is expected to be made on or about March 19, 2026 Joint Bookrunning Managers JefferiesUBS Investment BankCitigroupBarclays Lead Manager Chardan The date of this prospectus supplement is March 17, 2026 TABLE OF CONTENTS PROSPECTUS SUPPLEMENT ABOUT THIS PROSPECTUS SUPPLEMENT This prospectus supplement and the accompanying base prospectus are part of a registration statement on Form S-3 that we filedwith the Securities and Exchange Commission (the “SEC”) utilizing a “shelf” registration process. The first part is this prospectussupplement, which describes the specific terms of this offering of common stock and pre-funded warrants and also adds to and This prospectus supplement is not complete without, and may not be utilized except in connection with, the accompanying baseprospectus and any amendments to such prospectus. This prospectus supplement provides you with specific information regardingthe terms of this offering and our common stock, and also adds to and updates information contained in the accompanying base Before buying any of the securities that we are offering hereby, we urge you to carefully read this prospectus supplement and all ofthe information incorporated by reference herein, as well as the additional information described under the headings “Where YouCan Find More Information” and “Information Incorporated by Reference.” These documents contain important information that To the extent there is a conflict between the information contained in this prospectus supplement, on the one hand, and theinformation contained in any document incorporated by reference in this prospectus supplement that was filed with the SEC beforethe date of this prospectus supplement, on the other hand, you should rely on the information in this prospectus supplement. If any We further note that the representations, warranties and covenants made by us in any agreement that is filed as an exhibit to anydocument that is incorporated by reference herein were made solely for the benefit of the parties to such agreement, including, insome cases, for the purpose of allocating risk among the parties to such agreement, and should not be deemed to be a We have not, and the underwriters have not, authorized anyone to provide you with any information other than that contained orincorporated by reference in this prospectus supplement and in the accompanying base prospectus or in any related free writingprospectus that we authorize for use in connection with this offering and to which we have referred you. We take no responsibilityfor, and can provide no assurance as to the reliability of, any other information that others may give you. You should assume that This prospectus supplement does not constitute an offer to sell or the solicitation of an offer to buy any securities other than thesecurities described in this prospectus supplement or an offer to sell or the solicitation of an offer to buy such securities in any In this prospectus supplement, unless the context suggests otherwise, references to “SAB Bi