SEELAS生命科学集团股份有限公司美股招股说明书（2025-10-27版）

Warrants to Purchase up to 22,363,714 Shares of Common Stock Up to 22,363,714 Shares of Common Stock Underlying the Warrants We are offering to existing investors holding warrants (the “Investors”), in consideration for exercising (i) warrants issued to theInvestors on March 19, 2024 to purchase up to 6,514,658 shares of our common stock, par value $0.0001 per share (the “commonstock”) at the exercise price per share of $1.535 (the “March Warrants”), and (ii) warrants issued to the Investors on August 1, 2024 topurchase up to 15,849,056 shares of common stock at an exercise price per share of $1.325 (the “August Warrants,” and together withthe March Warrants, the “Existing Warrants”), new warrants to purchase up to 22,363,714 shares (the “New Warrants”) of ourcommon stock pursuant to this prospectus supplement and the accompanying prospectus and a warrant inducement agreement (the“Inducement Agreement”) with such Investors. Each New Warrant will have an exercise price per share equal to $2.00, will beimmediately exercisable and will expire on the five-year anniversary of their issuance date. We also refer to the New Warrants to purchase shares of common stock issued in this offering as the securities in this prospectussupplement. Our common stock is currently trading on The Nasdaq Capital Market (“Nasdaq”) under the stock symbol “SLS.” On October 24,2025, the closing price for our common stock, as reported on Nasdaq, was $1.99 per share. There is no established public trading market for the New Warrants and we do not expect a market to develop. In addition, we do notintend to list the New Warrants, nor do we expect the New Warrants to be quoted, on Nasdaq or any other national securities exchangeor any other nationally recognized trading system. Without an active trading market, the liquidity of the New Warrants will be limited. Investing in our securities involves a high degree of risk. See “Risk Factors” beginning on page S-6 of this prospectussupplement, as well as those risks described in our most recent Annual Report on Form 10-K for the year ended December 31,2024, and in our other filings with the Securities and Exchange Commission that are incorporated by reference into thisprospectus supplement. Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of thesesecurities or determined if this prospectus supplement is truthful or complete. Any representation to the contrary is a criminaloffense. We have retained A.G.P./Alliance Global Partners (“A.G.P.”) and Maxim Group LLC (“Maxim”) to act as our financial advisors (the“financial advisors”) in connection with this transaction. The financial advisors are not purchasing or selling any of the securitiesoffered by us in this offering and are not required to arrange the purchase or sale of any specific number or dollar amount of securities. (1) For New Warrants to purchase up to 22,363,714 shares of common stock and 22,363,714 shares of common stock underlying theNew Warrants. (2) In addition, we have agreed to reimburse certain expenses of the financial advisors in connection with the offering. See “Plan ofDistribution” for additional disclosure regarding financial advisors’ compensation. (3) The above proceeds do not give effect to any proceeds from the exercise of the New Warrants being issued in this offering. Delivery of the securities being offered pursuant to this prospectus supplement and the accompanying prospectus is expected to bemade on or about October 28, 2025. Financial Advisors The date of this prospectus supplement is October 24, 2025 TABLE OF CONTENTS Prospectus supplement ABOUT THIS PROSPECTUS SUPPLEMENTS-iPROSPECTUS SUPPLEMENT SUMMARYS-1THE OFFERINGS-5RISK FACTORSS-6SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTSS-8USE OF PROCEEDSS-9DIVIDEND POLICYS-10DESCRIPTION OF CAPITAL STOCKS-11PLAN OF DISTRIBUTIONS-16LEGAL MATTERSS-18EXPERTSS-18WHERE YOU CAN FIND MORE INFORMATIONS-18INCORPORATION OF CERTAIN INFORMATION BY REFERENCES-18 Prospectus ABOUT THIS PROSPECTUS2PROSPECTUS SUMMARY3RISK FACTORS9SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS10USE OF PROCEEDS12DILUTION13DESCRIPTION OF CAPITAL STOCK14DESCRIPTION OF DEBT SECURITIES18DESCRIPTION OF WARRANTS24DESCRIPTION OF RIGHTS26DESCRIPTION OF UNITS28LEGAL OWNERSHIP OF SECURITIES29PLAN OF DISTRIBUTION32LEGAL MATTERS35EXPERTS35WHERE YOU CAN FIND MORE INFORMATION35INCORPORATION BY REFERENCE35 ABOUT THIS PROSPECTUS SUPPLEMENT This document is in two parts. The first part is this prospectus supplement, which describes the terms of this offering of securities andalso adds to and updates information contained in the accompanying prospectus and the documents incorporated by reference into thisprospectus supplement and the accompanying prospectus. The second part, the accompanying prospectus dated May 1, 2024,including the documents incorporated by reference therein, provides more general information. Generally, when we re