天演药业美股招股说明书(2026-04-02版)

American Depositary Shares Representing Ordinary Shares This prospectus supplement relates to an offering by us of an aggregate ofAmerican depositary shares, or ADSs,each representing one and one quarter (1.25) of our ordinary shares, par value US$0.0001 per share, or Ordinary Shares. Our ADSs trade on The Nasdaq Global Market, or Nasdaq, under the trading symbol “ADAG”. On March31, 2026, thelast sale price of our ADSs as reported on Nasdaq was US$3.92 per ADS. We are an emerging growth company as that term is used in the Jumpstart Our Business Startups Act of 2012, and, assuch, are subject to certain reduced public company reporting requirements. See “Prospectus Supplement Summary —Implications of Being an Emerging Growth Company” on pageS-13of this prospectus. Investing in the ADSs involves risk. See “Risk Factors” beginning on page S-15of this prospectus supplement and in thedocuments incorporated by reference into this prospectus supplement and the accompanying base prospectus for a discussion ofcertain risks that you should consider in connection with an investment in the ADSs. Investors in the ADSs are purchasing securities of a Cayman Islands holding company rather than securities of oursubsidiaries that have substantive business operations in the United States or China. Adagene Inc. is a Cayman Islands holdingcompany that conducts its operations and operates its business in the U.S. through its U.S. subsidiary, Adagene Incorporated.In addition, Adagene Inc. conducts its operations in China through its PRC subsidiary, Adagene (Suzhou) Limited, or AdageneSuzhou. Such structure involves unique legal and operational risks to investors in the ADSs and Ordinary Shares. Inparticular, the PRC government has significant authority to exert influence on the ability of a company with substantiveoperations in China, such as us, to conduct its business, accept foreign investments or list on a U.S. or other foreignexchanges. For example, we face risks associated with regulatory approvals of offshore offerings, anti-monopoly regulatoryactions, oversight on cybersecurity and data privacy. Such risks could result in a material change in our operations and/or thevalue of the ADSs representing our Ordinary Shares or could significantly limit or completely hinder our ability to offer orcontinue to offer our Ordinary Shares represented by ADSs to investors and cause the value of such securities to significantlydecline or become worthless. As we are a holding company with substantive business operations in China, you should payspecial attention to disclosures included in our most recent annual report on Form 20-F incorporated by reference in thisprospectus and risk factors included herein. In addition, our auditor is headquartered in mainland China, a jurisdiction where the Public Company AccountingOversight Board, or PCAOB, was unable to conduct inspections without the approval of the Chinese authorities. Trading inour ADSs on the Nasdaq or over-the-counter may be prohibited, and as a result, our ADSs may be delisted under the HoldingForeign Companies Accountable Act, or HFCAA, if the PCAOB determines that it has been unable to inspect or investigatecompletely our auditor located in China for two consecutiveyears. On December16, 2021, the PCAOB issued the HFCAADetermination Report to notify the SEC of its determinations, or 2021 Determinations, that the PCAOB was unable to inspector investigate completely registered public accounting firms headquartered in mainland China and Hong Kong, including ourauditor. On December15, 2022, the PCAOB issued a report that vacated its December16, 2021 determination and removedmainland China and Hong Kong from the list of jurisdictions where it is unable to inspect or investigate completely registeredpublic accounting firms. As a result, we do not expect to be identified as a “Commission-Identified Issuer” under the HFCAAin the near future. However, whether the PCAOB will continue to be able to satisfactorily conduct inspections andinvestigations of PCAOB-registered public accounting firms headquartered in mainland China and Hong Kong is subject touncertainty and depends on a number of factors out of our, and our auditor’s, control, including positions taken by authoritiesof the PRC. The PCAOB is expected to continue to demand complete access to inspections and investigations againstaccounting firms headquartered in mainland China and Hong Kong in the future. The PCAOB is required under the HFCAA tomake its determination on an annual basis with regards to its ability to inspect and investigate completely accounting firmsbased in mainland China and Hong Kong. The possibility of being a “Commission-Identified Issuer” and risk of delistingcould continue to adversely affect the trading price of our securities. If the PCAOB determines in the future that it no longerhas full access to inspect and investigate accounting firms headquartered in mainland China and Hong Kong and we continue