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Filed Pursuant to Rule 424(b)(5)

Registration No. 333-287161

PROSPECTUS SUPPLEMENT
(TO PROSPECTUS DATED May 30, 2025)

Adagene Inc.

18,666,000 American Depositary Shares Representing 23,332,500 Ordinary Shares

This prospectus supplement relates to an offering by us of an aggregate of 18,666,000 American 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 April 1, 2026, the last sale price of our ADSs as reported on Nasdaq was US$4.61 per ADS.

We are an emerging growth company as that term is used in the Jumpstart Our Business Startups Act of 2012, and, as such, are subject to certain reduced public company reporting requirements. See “Prospectus Supplement Summary — Implications of Being an Emerging Growth Company” on page S-13 of this prospectus.

Investing in the ADSs involves risk. See “Risk Factors” beginning on page S-15 of this prospectus supplement and in the documents incorporated by reference into this prospectus supplement and the accompanying base prospectus for a discussion of certain 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 our subsidiaries that have substantive business operations in the United States or China. Adagene Inc. is a Cayman Islands holding company 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 Adagene Suzhou. Such structure involves unique legal and operational risks to investors in the ADSs and Ordinary Shares. In particular, the PRC government has significant authority to exert influence on the ability of a company with substantive operations in China, such as us, to conduct its business, accept foreign investments or list on a U.S. or other foreign exchanges. For example, we face risks associated with regulatory approvals of offshore offerings, anti-monopoly regulatory actions, oversight on cybersecurity and data privacy. Such risks could result in a material change in our operations and/or the value of the ADSs representing our Ordinary Shares or could significantly limit or completely hinder our ability to offer or continue to offer our Ordinary Shares represented by ADSs to investors and cause the value of such securities to significantly decline or become worthless. As we are a holding company with substantive business operations in China, you should pay special attention to disclosures included in our most recent annual report on Form 20-F incorporated by reference in this prospectus and risk factors included herein.

In addition, our auditor is headquartered in mainland China, a jurisdiction where the Public Company Accounting Oversight Board, or PCAOB, was unable to conduct inspections without the approval of the Chinese authorities. Trading in our ADSs on the Nasdaq or over-the-counter may be prohibited, and as a result, our ADSs may be delisted under the Holding Foreign Companies Accountable Act, or HFCAA, if the PCAOB determines that it has been unable to inspect or investigate completely our auditor located in China for two consecutive years. On December 16, 2021, the PCAOB issued the HFCAA Determination Report to notify the SEC of its determinations, or 2021 Determinations, that the PCAOB was unable to inspect or investigate completely registered public accounting firms headquartered in mainland China and Hong Kong, including our auditor. On December 15, 2022, the PCAOB issued a report that vacated its December 16, 2021 determination and removed mainland China and Hong Kong from the list of jurisdictions where it is unable to inspect or investigate completely registered public accounting firms. As a result, we do not expect to be identified as a “Commission-Identified Issuer” under the HFCAA in the near future. However, whether the PCAOB will continue to be able to satisfactorily conduct inspections and investigations of PCAOB-registered public accounting firms headquartered in mainland China and Hong Kong is subject to uncertainty and depends on a number of factors out of our, and our auditor’s, control, including positions taken by authorities of the PRC. The PCAOB is expected to continue to demand complete access to inspections and investigations against accounting firms headquartered in mainland China and Hong Kong in the future. The PCAOB is required under the HFCAA to make its determination on an annual basis with regards to its ability to inspect and investigate completely accounting firms based in mainland China and Hong Kong. The possibility of being a “Commission-Identified Issuer” and risk of delisting could continue to adversely affect the trading price of our securities. If the PCAOB determines in the future that it no longer has full access to inspect and investigate accounting firms headquartered in mainland China and Hong Kong and we continue to use such accounting firm to conduct audit work, we would be identified as a “Commission-Identified Issuer” under the HFCAA following the filing of the annual report for the relevant fiscal year, and if we were so identified for two consecutive years, trading in our securities on U.S. markets would be prohibited under the HFCAA.

The PRC government has significant oversight over the conduct of our business and its laws, regulations and policies may affect our operations. The PRC government has recently published new policies that affected certain industries with respect to matters such as cybersecurity, data privacy, antitrust and competition, foreign investments, and overseas listings, and we cannot rule out the possibility that it will in the future release regulations or policies regarding our industry that could adversely affect our business, financial condition and results of operations. Furthermore, the PRC regulatory authorities have issued new laws and regulations to exert more oversight and control over overseas securities offerings and other capital markets activities and foreign investment in China-based companies like us. Any such action, once taken by the PRC regulatory authorities, could significantly limit or completely hinder our ability to offer or continue to offer securities to investors and cause the value of such securities to significantly decline or in extreme cases, become worthless. For additional information, see “Item 3. Key Information — 3.D. Risk Factors — Risks Related to Doing Business in China” in our most recent annual report on Form 20-F incorporated by reference in this prospectus.

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As used in this prospectus supplement, “Adagene” refers to Adagene Inc., a Cayman Islands exempted company with limited liability, “Adagene Incorporated” refers to Adagene Incorporated, our U.S. subsidiary, “Adagene Suzhou” refers to Adagene (Suzhou) Limited, a PRC incorporated company with limited liability, “Adagene Hong Kong” refers to Adagene (Hong Kong) Limited, our Hong Kong intermediary holding company, and “we,” “us,” “our company,” or “our” refers to Adagene Inc. and its subsidiaries.

With a holding company structure, we currently rely principally on equity financing for our cash requirements, including the funds necessary to pay cash considerations for services we may incur. In the future, if we become profitable and generate cash flows from operating activities, we may rely principally on dividends and other distributions on equity from our U.S., PRC and other subsidiaries for our cash requirements, including the funds necessary to pay dividends and other cash distributions to our shareholders or for services of any debt we may incur. If any of our subsidiaries or any newly formed subsidiaries incur debt on their own behalf in the future, the instruments governing their debt may restrict their ability to pay dividends or make other distributions to us. In 2023, 2024 and 2025, Adagene Inc. made payments of US$20.5 million, US$16.3 million and US$28.5 million, respectively, in cash to Adagene Suzhou as consideration for providing services associated with research and development activities related to those intellectual properties owned by Adagene Inc. There were no intercompany loans provided by Adagene Inc. to Adagene Suzhou during the years ended and as of December 31, 2023, 2024 and 2025. As advised by our PRC legal counsel, Jingtian & Gongcheng, Adagene Suzhou is able to mark up and charge to Adagene Inc., its ultimate parent, for providing services associated with research and development activities related to those intellectual properties owned by Adagene Inc. and Adagene Inc. is able to make cash payments to Adagene Suzhou for considerations of such services. In the future, cash proceeds raised from overseas financing activities, including this offering, may be transferred by Adagene Inc., the Cayman Islands holding company, (i) to Adagene Incorporated, our U.S. subsidiary, (ii) through Adagene (Hong Kong) Limited, our Hong Kong subsidiary, to Adagene Suzhou, our PRC subsidiary and (iii) to other subsidiaries, via capital contribution, shareholder loans or consideration for the services rendered, as the case may be. Other than the above disclosed transfer of funds, we did not transfer any type of assets between Adagene Suzhou and other Adagene subsidiaries in 2023, 2024 or 2025. For risks associated with this structure, see “Item 3. Key Information — 3.D. Risk Factors — Risks Related to Doing Business in China — We may rely on dividends and other distributions on equity paid by our PRC subsidiary to fund any cash and financing requirements that we may have, and any limitation on the ability of our PRC subsidiary to make payments to us could have material and adverse effect on our ability to conduct our business” and “— PRC regulation of loans to and direct investment in PRC entities by offshore holding companies and governmental control of currency conversion may delay or prevent us from using the proceeds of our public offering to make loans or additional capital contributions to our PRC subsidiary, which could materially and adversely affect our liquidity and our ability to fund and expand our business” in our most recent annual report on Form 20-F incorporated by reference in this prospectus.

	PER ADS	TOTAL
Initial public offering price	$3.750	$69,997,500
Underwriting discount(1)	$0.225	$4,199,850
Proceeds, before expenses, to us	$3.525	$65,797,650

(1)

See “Underwriting” for a description of the compensation payable to the underwriters.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus supplement or the accompanying base prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The underwriters expect to deliver the ADSs against payment in New York, New York on or about April 6, 2026.

Joint Bookrunning Managers

Leerink Partners

LifeSci Capital

Co-Manager

Lucid Capital Markets

Prospectus supplement dated April 2, 2026.

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PROSPECTUS SUPPLEMENT

	Page
About This Prospectus Supplement		S-ii
Special Note Regarding Forward-Looking Statements		S-iii
Prospectus Supplement Summary		S-1
The Offering		S-14
Risk Factors		S-15
Use of Proceeds		S-18
Dividend Policy		S-19
Capitalization		S-20
Dilution		S-21
Taxation		S-22
Underwriting		S-28
Legal Matters		S-32
Experts		S-33
Where You Can Find More Information		S-34
Incorporation by Reference		S-35

PROSPECTUS

	Page
About This Prospectus		1
Our Company		3
Risk Factors		14
Cautionary Note Regarding Forward-Looking Statements		33
Use of Proceeds		35
Capitalization and Indebtedness		36
Description of Share Capital and Memorandum and Articles of Association		37
Description of Warrants		46
Description of Units		47
Forms of Securities		48
Description of American Depositary Shares		50
Enforceability of Civil Liabilities		65
Taxation		67
Plan of Distribution		68
Expenses		72
Incorporation of Certain Documents by Reference		73
Legal Matters		74
Experts		75
Where You Can Find More Information		76

You should rely only on the information contained or incorporated by reference into this prospectus supplement or in any free writing prospectus filed by us with the SEC. We have not authorized any other person to provide you with different information. If anyone provides you with different or inconsistent information, you should not rely on it. You should not assume that the information contained or incorporated by reference into this prospectus supplement or in any free writing prospectus is accurate as of any date other than the respective dates thereof. Our business, financial condition, results of operations and prospects may have changed since those dates.

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ABOUT THIS PROSPECTUS SUPPLEMENT

This document consists of two parts. The first part is this prospectus supplement, which describes the specific terms of this offering. The second part is the accompanying base prospectus, which is part of a registration statement that we filed with the SEC using a “shelf” registration process. The accompanying base prospectus describes the general terms of the securities that may be offered pursuant to the accompanying base prospectus and the general manner in which those securities will be offered, some of which may not apply to this offering. This prospectus supplement and the information incorporated by reference in this prospectus supplement supplements, updates and amends the information contained in the accompanying base prospectus.

Before buying any of the securities offered by this prospectus supplement, you should carefully read both this prospectus supplement and the accompanying base prospectus, together with all of the information incorporated by reference in this prospectus supplement, as well as the additional information described under the heading “Where You Can Find More Information” and “Information Incorporated by Reference.” These documents contain important information that you should consider when making your investment decision. We have filed or incorporated by reference exhibits to the registration statement of which this prospectus supplement forms a part. You should read the exhibits carefully for provisions that may be important to you.

To the extent there is a conflict between the information contained in this prospectus supplement, on the one hand, and the information contained in the accompanying base prospectus or in any document incorporated by reference in this prospectus supplement, on the other hand, you should rely on the information in this prospectus supplement, provided that if any statement in one of these documents is inconsistent with a statement in another document having a later date — for example, a document incorporated by reference in this prospectus supplement — the statement in the document having the later date modifies or supersedes the earlier statement.

The information contained in this prospectus supplement, the accompanying base prospectus or any document incorporated by reference in this prospectus supplement is accurate only as of their respective dates, regardless of the time of delivery of this prospectus supplement, the accompanying base prospectus or the documents incorporated by reference in this prospectus supplement or in the accompanying base prospectus or the sale of any securities. Our business, financial condition, results of operations and prospects may have changed materially since those dates.

Neither we nor the underwriters have authorized anyone to provide you with information that is different from that contained or incorporated by reference in this prospectus supplement, the accompanying base prospectus, or any free writing prospectus we may authorize to be delivered or made available to you. Neither we nor the underwriters take responsibility for, or provide assurance as to the reliability of, any other information that others may give you. This prospectus supplement does not constitute an offer to sell or the solicitation of an offer to buy any securities other than the securities described in this prospectus supplement or an offer to sell or the solicitation of an offer to buy such securities in any circumstances in which such offer or solicitation is unlawful.

For investors outside the United States: Neither we nor the underwriters have taken any action that would permit the offering or possession or distribution of this prospectus supplement in any jurisdiction where action for that purpose is required, other than in the United States. Persons outside the United States who come into possession of this prospectus supplement must inform themselves about, and observe any restrictions relating to, the offering of the securities described herein and the distribution of this prospectus supplement outside the United States.

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SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

This prospectus supplement contains forward-looking statements that reflect our current expectations and views of future events. All statements other than statements of historical facts are forward-looking statements. These forward-looking statements are made under the “safe harbor” provision under Section 21E of the Securities Exchange Act of 1934, as amended, or the Exchange Act, and as defined in the Private Securities Litigation Reform Act of 1995. These statements involve known and unknown risks, uncertainties and other factors, including but not limited to Adagene’s ability to demonstrate the safety and efficacy of its drug candidates; the clinical results for its drug candidates, which may not support further development or regulatory approval; the content and timing of decisions made by the relevant regulatory authorities regarding regulatory approval of Adagene’s drug candidates; Adagene’s ability to achieve commercial success for its drug candidates, if approved; Adagene’s ability to obtain and maintain protection of intellectual property for its technology and drugs; Adagene’s reliance on third parties to conduct drug development, manufacturing and other services; Adagene’s limited operating history and Adagene’s ability to obtain additional funding for operations and to complete the development and commercialization of its drug candidates; Adagene’s ability to enter into additional collaboration agreements beyond its existing strategic partnerships or collaborations, and the impact of the outbreak of a widespread health epidemic on Adagene’s clinical development, commercial and other operations, as well as those risks more fully discussed in the “Risk Factors” section in Adagene’s filings with the SEC. Such known and unknown risks, uncertainties and other factors may cause our actual results, performance or achievements to be materially different from those expressed or implied by the forward-looking statements. In some cases, you can identify these forward-looking statements by terminology such as “may,” “will,” “expect,” “anticipate,” “aim,” “estimate,” “intend,” “plan,” “believe,” “is/are likely to,” “potential,” “continue” or other similar expressions. We have based these forward-looking statements largely on our current expectations and projections about future events and financial trends that we believe may affect our financial condition, results of operations, business strategy and financial needs.

These forward-looking statements include, but are not limited to, statements about:

•

our goals and growth strategies;

•

our future business development, results of operations and financial condition;

•

the timing of the initiation, progress and potential results of our preclinical studies, clinical trials and our discovery programs;

•

our ability to utilize our proprietary Dynamic Precision Library platform, or DPL, to design, construct and develop next-generation antibodies;

•

our ability to advance product candidates into, and successfully complete, clinical trials;

•

the timing or likelihood of regulatory filings and approvals;

•

our estimates of the number of patients who suffer from the diseases we are targeting and the number of patients that may enroll in our clinical trials;

•

the commercializing of our product candidates, if approved;

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our ability and the potential to successfully manufacture and supply our product candidates for clinical trials and for commercial use, if approved;

•

future strategic arrangements and/or collaborations and the potential benefits of such arrangements;

•

our anticipated use of our existing resources and the proceeds from our initial public offering;

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our estimates regarding expenses, future revenue, capital requirements and needs for additional financing and our ability to obtain additional capital;

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the sufficiency of our existing cash and cash equivalents to fund our future operating expenses and capital expenditure requirements;

•

our ability to retain the continued service of our key personnel and to identify, hire and retain additional qualified professionals;

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•

the implementation of our business model, strategic plans for our business and product candidates;

•

the scope of protection we are able to establish and maintain for intellectual property rights, such as our proprietary DPL, which includes NEObody platform, SAFEbody platform and POWERbody technology platforms, product candidates and discovery programs;

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our potential to enter into new collaborations;

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our ability to contract with third-party suppliers and manufacturers and their ability to perform adequately;

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the pricing, coverage and reimbursement of our product candidates, if approved;

•

developments relating to our competitors and our industry, including competing product candidates and therapies;

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the direct and indirect impact of the outbreak of a widespread health epidemic on our business and operations and on development of our clinical and preclinical programs, and the duration and impact of such widespread health epidemic or any of its variants that may affect, precipitate or exacerbate one or more of any of the risks and uncertainties mentioned in this prospectus supplement;

•

relevant government policies and regulations relating to our business and industry;

•

general economic and business conditions in the markets we have businesses; and

•

assumptions underlying or related to any of the foregoing.

We would like to caution you not to place undue reliance on these forward-looking statements and you should read these statements in conjunction with the risk factors disclosed herein, in the accompanying base prospectus, and in the documents incorporated by reference therein, and other risks outlined in our other filings with the Securities and Exchange Commission, or the SEC. Those risks are not exhaustive. We operate in an evolving environment. New risks emerge from time to time and it is impossible for our management to predict all risk factors and uncertainties, nor can we assess the impact of all factors on our business or the extent to which any factor, or combination of factors, may cause actual results to differ materially from those contained in any forward-looking statement. We qualify all of our forward-looking statements by these cautionary statements.

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PROSPECTUS SUPPLEMENT SUMMARY

This summary highlights selected information contained elsewhere in this prospectus supplement and in the documents we incorporate by reference. This summary does not contain all of the information you should consider before making an investment decision. You should read this entire prospectus supplement carefully, especially the risks of investing in our Ordinary Shares or ADSs discussed under “Risk Factors” beginning on page S-15 of this prospectus supplement, along with our consolidated financial statements and notes to those consolidated financial statements and the other information incorporated by reference in this prospectus supplement.

OVERVIEW

We are a platform-driven, clinical-stage biotechnology company dedicated to transforming the discovery and development of novel antibody-based cancer immunotherapies. We leverage computational biology to design and develop novel antibodies that address unmet patient needs. Powered by our proprietary Dynamic Precision Library (DPL) platform, which fuels our NEObody®, SAFEbody®, and POWERbody® technologies, we are developing a highly differentiated pipeline of novel immunotherapies. Our lead candidate is an anti-CTLA-4 SAFEbody, ADG126 (muzastotug), which is currently in phase 1b/2 and phase 2 clinical development, and focused initially on metastatic microsatellite-stable (MSS) colorectal cancer (CRC). We also have a robust pipeline of earlier stage candidates that apply our NEObody and SAFEbody technologies to targets associated with toxicity challenges, including modalities with potent efficacy features, such as Fc-empowered antibodies (e.g., IgG1 isotype and its enhanced version) and bi/multispecific T-cell engagers. Additionally, we have forged strategic collaborations with reputable global partners that leverage our SAFEbody technology in multiple approaches at the vanguard of science.

We aim to push the boundaries of antibody discovery and engineering through the precise design, construction, and selection of antibody product candidates intractable to traditional antibody technology. We have pioneered a dynamic antibody technology interface to harness the conformational diversity of antibodies, which enlarges epitope sampling of a given drug target for differentiated therapeutic antibody development. Additionally, we have proprietary precision masking technology and specialized antibody engineering capabilities which enable us to design therapeutics with unique features.

Our DPL fuels three antibody technology platforms, which can be used alone or together to create novel, differentiated antibody-based therapeutic candidates:

•

The NEObody technology platform is a fully synthetic phage display and yeast display-based antibody discovery technology, which we believe is differentiated from other synthetic antibody technologies through its innovative designs and precise constructions. NEObody technology enables the generation of antibodies designed with dynamic binding sites that adapt kinetically to unique epitopes, triggering a novel MOA. The species cross-reactive antibodies generated by NEObody technology not only have the potential to reveal new biological functions of the targets, but also facilitate preclinical studies using various immune system intact animal models, resulting in high fidelity translation from preclinical to clinical studies. We refer to antibodies generated by our NEObody technology as NEObodies.

•

The SAFEbody technology platform is designed to mask an antibody binding interface with a masking motif, which then prevents an antibody from binding to its target in healthy tissues, minimizing on target, off tumor toxicities. The masking motif is designed to activate, or unmask, the antibody to allow binding in the tumor microenvironment, or TME, where certain activation conditions such as a protease is upregulated as compared to healthy tissues, allowing the antibody to bind to its target for tumor killing. Our SAFEbody enabled therapeutic candidates are therefore designed to be activated predominantly in the TME while remaining largely in an inactive state in healthy tissues. Our SAFEbody technology can be applied to mask the binding sites of any antibodies including but not limited to NEObodies. We refer to such masked antibodies as SAFEbodies. Notably, SAFEbody technology can be applied to our NEObodies, such as what we did with ADG116 to potentially achieve an increased therapeutic index with ADG126.

•

The POWERbody technology platform enables the creation of new versions of antibodies, which may be bi/multi-specific T-cell engagers, or TCEs, or Fc-enhanced antibodies, antibody-drug conjugates, or ADCs, or antibodies that are designed to reach beyond the therapeutic potency of

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traditional monospecific antibodies. Our POWERbody candidates incorporate SAFEbody precision masking technology and are designed to improve antitumor activity while maintaining the enhanced safety profile for potentially safe and durable immunotherapies.

These proprietary technology platforms allow us to engineer and select species cross-reactive antibodies designed to dynamically adapt to unique and evolutionally conserved epitopes. We believe that comprehensive in vivo preclinical evaluations using these species cross-reactive antibodies are the key to assess the efficacy and safety potential of tailor-made antibody candidates before progressing them into lengthy and costly clinical trials. Our NEObody, SAFEbody and POWERbody technology platforms are all designed to facilitate favorable druggability, manageable CMC attributes, and reduced immunogenicity.

Our Robust, Transformative Pipeline

By leveraging our proprietary DPL and three platform technologies, we have developed a robust pipeline of innovative product candidates in various stages of development, including our lead candidate, ADG126 SAFEbody which is currently in phase 1b/2 and phase 2 clinical development.

ADG126 (muzastotug) is a fully human anti-CTLA-4 SAFEbody®, which applies SAFEbody precision masking technology to its parental unmasked version, ADG116, to further enhance safety and efficacy profiles by masking the antibody binding site which is then conditionally activated in the TME to limit on target, off tumor toxicity.

ADG126 targets a unique epitope of CTLA-4 and is designed to provide an enhanced therapeutic window and optimize efficacy by enabling higher, more frequent and repeated doses of anti-CTLA-4 therapy with constant target engagement that may unlock the full potential of CTLA-4 as a proven target for strong ADCC-mediated Treg depletion in the TME. ADG126 has shown a potential best-in-class profile in clinic, which is consistent with and enabled by the broad species cross-reactivity of ADG126 for extensive preclinical evaluation from mouse, rats and monkeys, including GLP toxicology data. ADG126 is currently in phase 1b/2 and phase 2 clinical development, with a focus on randomized phase 2 dose-optimization study in combination with Merck’s (known as MSD outside of the US and Canada) anti-PD-1 therapy, KEYTRUDA® (pembrolizumab) in patients with advanced/metastatic MSS CRC. In 2025, we had a productive Type B (end of phase 1) meeting and we believe we gained regulatory alignment with the US Food and Drug Administration (FDA) on phase 2 and phase 3 trial design elements including dosing regimen, patient population, primary and secondary endpoints. The FDA has since designated ADG126, in combination with pembrolizumab, as a Fast Track product for adult patients with metastatic MSS CRC without current or active liver metastases. In February 2025, we announced an investigator initiated phase 2 neoadjuvant trial of ADG126 for patients with stage II or stage III colorectal cancer. In addition, Sanofi is sponsoring a phase 1b/2 dose escalation and expansion study of ADG126 in combination with SAR445877 (Sanofi’s PD-1 x IL-15 fusion protein) on adults with advanced solid tumors.

Earlier stage candidates that apply our SAFEbody® precision masking technology include ADG206, a masked, Fc-enhanced anti-CD137 agonistic POWERbody. ADG206 incorporates SAFEbody® precision masking technology and is designed to achieve improved safety and efficacy. ADG206 has demonstrated enhanced crosslinking by FcγRIIb in vitro upon activation and antitumor activity in vivo, while the SAFEbody® masking technology limits on-target off-tumor toxicities by preferential activation in the TME. Preclinical data demonstrated that ADG206 was well tolerated, with normal pharmacokinetic properties and minimal activation in circulation. It also had robust anti-tumor activity as a single agent in multiple tumor models, with 4-fold stronger anti-CD137 agonistic activity of its activated form than a benchmark antibody (urelumab analog). ADG206 monotherapy demonstrated favorable safety data in phase 1 evaluation.

Additionally, we have two IND-ready preclinical programs (ADG138, a novel HER2xCD3 POWERbody® bispecific TCE that is masked on both arms, and ADG153, a masked, IgG1 anti-CD47 SAFEbody), as well as another preclinical program (ADG152, a CD20xCD3 POWERbody with masking on the CD3 arm) in the IND-enabling phase. We have multiple masked T-cell engagers in discovery. We are developing POWERbody® TCEs with co-stimulatory signal such as CD28, enabled by our suite of antibody platform technologies. We have previously published preclinical data showing the scientific rationale for these differentiated programs. See “Item 4.B. Business Overview — IND-Ready Candidates & Preclinical Pipeline” in our most recent annual report on Form 20-F incorporated by reference in this prospectus supplement.

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We also have two clinical-stage NEObody product candidates, ADG116 and ADG106, for which we have conducted previous clinical studies that demonstrate the potential clinical benefits of targeting a unique epitope with our NEObody platform. ADG116 is clinically active and ready to advance into further clinical development as resources allow. ADG106 has been deprioritized.

Further, we have out-licensed the Greater China rights of ADG104, an anti-PD-L1 mAb currently in phase 2 clinical development, to Sanjin, and the Greater China rights of ADG125, a novel anti-CSF-1R mAb in phase 2 development, to Dragon Boat Biopharmaceuticals. We have the right to apply for the patents derived from our core and key technologies pertaining to ADG104 and ADG125 in the rest of the world, where we retain a majority of the economic benefits.

Our Global Partnerships and Collaborations

We have a successful track record of collaborations and partnerships with global biopharmaceutical companies and academic institutions. So far, we have established multiple collaborations and we continue to seek partnership opportunities where we can leverage our proprietary technology platform to develop novel antibodies to address unmet medical needs.

We enter into collaborations with biotechnology and pharmaceutical companies to leverage the power of our technology platforms, creating a network of potential future revenue streams that complement future long-term value from our wholly-owned pipeline. These collaborations include both technology licensing agreements and outlicensing of product candidates, both of which allow us to retain significant future participation in product sales through royalties paid on net sales. In the future, we may also enter into strategic collaborations which may involve joint development for our preclinical and/or clinical assets to both accelerate the path to clinic and drive global commercialization.

Our technology licensing agreements with Sanofi and Exelixis focus on developing antibody-based therapeutics against tumor targets using our SAFEbody technology. In 2025:

•

Sanofi exercised its option for a third SAFEbody discovery program, building on the 2022 collaboration.

•

We advanced a third masked ADC program with Exelixis against a solid tumor target, building on the 2021 collaboration.

•

We partnered with Third Arc Bio to develop two masked CD3 T cell engagers, expanding SAFEbody into next-generation T cell therapies.

•

We collaborated with ConjugateBio on bispecific ADCs using Adagene-derived antibody, further demonstrating scalable platform potential.

We have out-licensed the Greater China rights for two antibody candidates to Sanjin and its affiliates. To further advance our pipeline, we have also put in place various clinical collaborations, including an agreement with Roche who is sponsoring and conducting a triple combination trial with ADG126, atezolizumab and bevacizumab in first-line hepatocellular carcinoma (HCC), clinical collaboration and supply agreement with Merck who provides pembrolizumab for certain of our combination clinical trials, and agreement with research organization in Singapore for investigator-initiated trial of our clinical candidate.

In March 2026, we formed a clinical collaboration with Incyte (Nasdaq:INCY) to evaluate the combination of muzastotug (ADG126) and INCA33890, a TGFβR2 × PD-1 bispecific antibody, in patients with microsatellite stable colorectal cancer (MSS CRC) with or without liver metastases. The phase 1 study of INCA33890 and ADG126 is expected to begin in 2026 in 3L MSS CRC patients with and without liver metastases. The study will be sponsored and conducted by Incyte and we will provide clinical supply of ADG126.

Our collaborations empower our growth by generating cash flow and revenues that partially offset expenditures on our internal research and development programs, expand our knowledge base regarding antibody technology across multiple targets and antibodies provided by our partners, and provide us with future joint development opportunities. In addition to collaborations with biotechnology and pharmaceutical companies, we also work with globally renowned medical experts to advance our technology and product pipeline.

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RECENT DEVELOPMENTS

AACR Poster Presentations

Our muzastotug (ADG126) will be highlighted in two poster presentations at this year’s American Association of Cancer Research (AACR) conference with details.

AACR 2026 Abstract Number: CT054

The MORPHEUS-Liver study (NCT04524871) is a phase 1b/2 open-label randomized umbrella study designed to evaluate immunotherapy-based combinations in patients with locally advanced or metastatic HCC. As of July 11, 2025, six patients had been randomized to the triple combination of muzastotug, atezolizumab and bevacizumab and 40 patients had received atezolizumab and bevacizumab in the active control arm. Interim results from patients in the muzastotug arm (18.8 months median duration of follow-up) demonstrated a 50.0% overall response rate (ORR; 3/6; RESIST v1.1), median progression free survival (mPFS) of 8.2 months, and median overall survival (mOS) of greater than 22 months that had not yet been reached. This compared favorably to the 40 patients in the active control arm (17.2 months median duration of follow-up) that demonstrated an ORR of 17.5% (7/40), mPFS of 4.3 months, and mOS of 17.5 months.

The triplet regimen of muzastotug, atezolizumab and bevacizumab was well-tolerated with safety data comparable to the doublet active control arm of atezolizumab and bevacizumab. Grade 3 or greater treatment-related adverse events (TRAEs) were 50% (3/6) in the muzastotug arm and 45% (18/40) in the active control arm. We believe the safety data observed for muzastotug could allow for continuous dosing without impacting treatment with atezolizumab and bevacizumab. Further details from the interim results will be presented at the AACR conference April 17 – 22, 2026.

AACR 2026 Abstract Number: CT083

A phase 1b/2 single arm study (NCT05405595) is evaluating the triple combination of muzastotug, pembrolizumab and fruquintinib in patients with advanced and metastatic microsatellite stable (MSS) colorectal cancer (CRC). As of February 21, 2026, nine patients have been treated with the triple combination — four (4) patients at a dose of 10mg/kg every 6 weeks (Q6W) of muzastotug and five (5) patients at a dose of 15mg/kg of muzastotug. Interim results demonstrated a 25% ORR (1/4) among patients in the 10mg/kg arm, and a 40% ORR (2/5) among patients in the 15mg/kg arm.

The triplet regimen was well-tolerated with safety data comparable to historical controls with fruquintinib monotherapy, despite the addition of dual immunotherapy. There were no dose-limiting toxicities, 25 – 60% Grade 3 TRAEs, and no Grade 4 or Grade 5 TRAEs. Further details from the interim results will be presented at the AACR conference April 17 – 22, 2026.

Updated Data from Phase 1b/2 Study of Muzastotug in Combination with KEYTRUDA® (pembrolizumab) in Late-line Patients with Microsatellite Stable Colorectal Cancer Demonstrate Improved Durability of Response

Updated Interim Efficacy Results from Phase 1b/2 Trial

Previous results from a data cut on April 22, 2025 were presented at the annual American Society of Clinical Oncology meeting in June 2025. As of the latest data cut on January 24, 2026, a total of 67 MSS CRC patients with no liver metastases, including those with peritoneal involvement, have been treated with muzastotug at a dose of either 10 mg/kg or 20 mg/kg, in combination with pembrolizumab. The 10 mg/kg dose was administered once every three weeks or once every six weeks. The 20 mg/kg dose was administered once as a loading dose, followed by 10 mg/kg every three weeks, or 20 mg/kg every six weeks.

Among 65 efficacy-evaluable patients in the dose expansion phase, those in the combined 10 mg/kg cohorts (N=39) demonstrated an ORR of 13% (5/39), which was comprised of an ORR of 0% (0/10) in the Q6W regimen cohort and an ORR of 17% (5/29) in the every 3 weeks (Q3W) cohort. The higher response

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rates in the Q3W cohort and robust safety data, to keep patients stable without new lesions, in the Q6W cohort helped inform the decision for the dosing regimens utilized in Arm A of the ongoing randomized phase 2 trial.

The combined 20 mg/kg cohorts (N=26) demonstrated a confirmed ORR of 31% (8/26), including 25% (3/12) in the Q6W cohort and 36% (5/14) in the 20 mg/kg loading dose cohort (20 mg/kg, followed by 10 mg/kg Q3W). The higher response rate in the 20 mg/kg cohorts helped inform the 20 mg/kg induction/maintenance dosing regimen utilized in Arm B of the ongoing randomized phase 2 trial.

Median progression-free survival was 4.8 months in the 10 mg/kg cohorts and 6.7 months in the 20 mg/kg cohorts. Notably, mPFS was 15.4 months among the 14 patients in the 20 mg/kg loading dose cohort, compared with 4.9 months among the 12 patients in the 20 mg/kg Q6W cohort, further supporting the induction/maintenance approach now being evaluated in the ongoing randomized phase 2 study.

Muzastotug +
Pembrolizumab
200 mg Q3W

10 mg/kg

20 mg/kg

Subpopulation
(N)

Combined
(N=39)

Q6W
(N=10)

Q3W
(N=29)

Combined
(N=26)

Q6W
(N=12)

20 mg/kg x1 +
10 mg/kg Q3W
(N=14)

ORR, % (95% CI)

13
(4 – 27)

0(a)
(0 – 31)

17
(6 – 36)

31
(14 – 52)

25
(5 – 57)

36
(13 – 65)

BoR, N (%)

1(4)

1(8)

5 (13)

5(b) (17)

7 (27)

2 (17)

5 (36)

24 (62)

7 (70)

17 (59)

14 (54)

7 (58)

7 (50)

DCR
(CR+PR+SD), %, (95% CI)

74
(58 – 87)

70
(35 – 93)

76
(56 – 90)

85
(65 – 96)

83
(52 – 98)

86
(57 – 98)

mPFS,
months (95%CI)

4.8
(2.6 – 6.7)

4.5
(1.4 – 7.1)

4.8
(2.6 – 6.7)

6.7
(2.7 – NA)

4.9
(1.2 – NA)

15.4
(2.6 – NA)

6-month PFS, %,
(95% CI)

39.6
(24.3 – 54.6)

40
(12.3 – 67)

39.6
(21.9 – 56.8)

50.4
(29.5 – 68.1)

45.5
(16.7 – 70.7)

54.5
(25.4 – 76.5)

Abbreviations: BoR (best overall response), CR (complete response), PR (partial response), SD (stable disease), DCR (disease control rate)

Efficacy evaluable set (participants who received ≥1 post-baseline scheduled imaging scan)

(a)

One patient with target lesion assessed as “PR”, overall assessment as “PD” due to new lesion.

(b)

Including one unconfirmed PR (10 mg/kg Q3W)

mOS for the 10 mg/kg cohorts was 19.8 months with a 23.8-month median follow-up, comparing favorably with current standard of care treatments and historical benchmarks in the 11 – 12 month range1. mOS for the 20 mg/kg cohorts was not yet reached, with a median follow-up of 13.1 months. Patients in the 20 mg/kg cohorts demonstrated a 1-year OS rate of 80.8%, while patients in the 10 mg/kg cohorts demonstrated an OS rate of 70.1% at 12 months and 48% at 24 months.

Updated Interim Safety Results from Phase 1b/2 Trial

As of the January 24, 2026 data cutoff, across 67 patients in all cohorts, there was a low 4% overall discontinuation rate, no dose limiting toxicities, and no treatment-related Grade 4 or 5 adverse events (TRAEs). Grade 3 TRAEs were 15% in the combined 10 mg/kg cohorts (0% Q6W; 20% Q3W) and 38% in the combined 20 mg/kg cohorts (25% Q6W; 50% loading dose cohort), which were generally transient and manageable.

The most common treatment-related adverse events were pruritus, fatigue, hypothyroidism, and diarrhea. Regarding GI-related adverse events, the overall incidence of diarrhea, colitis and immune-mediated enterocolitis was relatively low, and such events were generally transient and manageable. The

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three patients with Grade 3 colitis had all recovered at the time of data cut-off. Infliximab use was low, with approximately 10% of patients requiring its use for management of GI toxicity.

Preferred Term	All Grade n (%)	Grade 1 n (%)	Grade 2 n (%)	Grade 3 n (%)
Any TRAE	57 (85.1)	15 (22.4)	26 (38.8)	16 (23.9)
Pruritus	25 (37.3)	20 (29.9)	5 (7.5)	0
Fatigue	15 (22.4)	12 (17.9)	3 (4.5)	0
Hypothyroidism	13 (19.4)	3 (4.5)	10 (14.9)	0
Diarrhea	12 (17.9)	5 (7.5)	4(6)	3 (4.5)
Adrenal insufficiency	10 (14.9)	1 (1.5)	9 (13.4)	0
Decreased appetite	8 (11.9)	6(9)	2(3)	0
Alanine aminotransferase increased	7 (10.4)	2(3)	4(6)	1 (1.5)
Arthralgia	7 (10.4)	5 (7.5)	2(3)	0
Nausea	7 (10.4)	4(6)	3 (4.5)	0
Colitis	7 (10.4)	0	4(6)	3 (4.5)
Immune-mediated enterocolitis	3 (4.5)	0	2(3)	1 (1.5)

Ongoing Phase 2 Randomized Trial

The randomized phase 2 trial design, incorporated into our existing protocol for the phase 1b/2 Trial (NCT05405595) was established following a meeting with the FDA in 2025 and is evaluating two different dose regimens. The first patient was treated in October 2025, and results are expected in the first half of 2027. We intend to take full advantage of the recent Fast Track designation by the FDA to initiate the a potential registrational study of muzastotug pending further FDA feedback regarding the dose regimen identified from ongoing trials.

•

Patient Population: The trial will enroll up to 60 late-line patients with MSS CRC without liver metastases, including those with peritoneal metastasis/involvement. Patients are randomized 1:1 into one of two treatment arms with muzastotug in combination with pembrolizumab.

•

Dose and Regimen: Both arms utilize an induction/maintenance regimen, without cycle limitations for muzastotug.

•

Arm A: 10 mg/kg induction dose of muzastotug plus 200 mg pembrolizumab Q3W for 4 doses followed by one 200 mg dose of pembrolizumab; the maintenance phase will dose 10 mg/kg muzastotug Q6W plus 400 mg of pembrolizumab Q6W.

•

Arm B: 20 mg/kg induction dose of muzastotug Q6W plus 400 mg pembrolizumab Q6W for 2 doses; the maintenance phase will dose muzastotug at 15 mg/kg Q6W plus 400 mg pembrolizumab Q6W.

•

Endpoints: The primary endpoint will be ORR. Secondary endpoints include duration of response, PFS, and OS.

OUR CHALLENGES

Investors are investing in equity securities of a Cayman Islands holding company rather than equity securities of our subsidiaries that have substantive business operations in the United States or China. Adagene Inc. is a Cayman Islands holding company 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. Our corporate group does not include any variable interest entities. Such structure involves unique risks to investors in the ADSs or ordinary shares. You should carefully consider all of the information in this prospectus supplement and in any documents incorporated by reference to this prospectus supplement, including disclosures included in our most recent annual report on Form 20-F incorporated by reference in this prospectus supplement, before making an

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investment in our ADSs. In particular, as we are a holding company with substantial business operations in China, you should pay special attention to subsections headed “Recent Regulatory Developments” in this prospectus supplement and “Item 5.B. — Liquidity and Capital Resources — Holding Company Structure” and Item 3.D. Risk Factors — Risks Related to Doing Business in the PRC,” in our most recent annual report on Form 20-F incorporated by reference in this prospectus supplement, including but not limited to risk factor such as “uncertainties with respect to the PRC legal system, including uncertainties regarding the enforcement of laws, and sudden or unexpected changes in policies, laws and regulations in China could adversely affect us.”

The PRC government has significant authority to exert influence on the ability of a company with substantive operations in China, such as us, to conduct its business, accept foreign investments or list on a U.S. or other foreign exchanges. For example, we face risks associated with regulatory approvals of offshore offerings, anti-monopoly regulatory actions, oversight on cybersecurity and data privacy, as well as the lack of PCAOB inspection on our auditor. Such risks could result in a material change in our operations and/or the value of our ADSs or could significantly limit or completely hinder our ability to offer or continue to offer ADSs and/or other securities to investors and cause the value of such securities to significantly decline or be worthless. The PRC government also has significant oversight and discretion over the conduct of our business and as such may influence our operations at any time, which could result in a material adverse effect on our operations. The PRC government has recently published new policies and made statements, such as those related to regulatory approvals of offshore offerings and data security or anti-monopoly concerns, that although did not target our company specifically, nevertheless have significantly affected certain industries and other PRC-based issuers as a whole, and we cannot rule out the possibility that it will in the future release regulations or policies regarding the industry where we operate, which could adversely affect our business, financial condition and results of operations. Furthermore, the PRC government has recently indicated an intent to exert more oversight and control over overseas securities offerings and other capital markets activities and foreign investment in China-based companies like us. These risks could result in a material change in our operations and the value of our ordinary shares or the ADSs or could significantly limit or completely hinder our ability to conduct our business, accept foreign investments, maintain listing on Nasdaq or list on other foreign exchange, and offer or continue to offer securities to investors, and cause the value of such securities to significantly decline or become worthless. Below please find a summary of the principal risks we face, organized under relevant headings. These risks are discussed more fully in the section titled “Risk Factors” in this prospectus supplement and the most recent annual report on Form 20-F incorporated by reference.

Risks Related to Doing Business in the PRC

Risks and uncertainties related to doing business in China include, but are not limited to, the following:

•

Uncertainties with respect to the PRC legal system, including uncertainties regarding the enforcement of laws, and sudden or unexpected changes in policies, laws and regulations in China could adversely affect us;

•

PRC government has significant oversight over the conduct of our business and as such may influence our operations at any time, which may potentially result in a material adverse effect on our operations;

•

The PCAOB had historically been unable to inspect our auditor in relation to their audit work performed for our financial statements and the inability of the PCAOB to conduct inspections of our auditor in the past has deprived our investors with the benefits of such inspections;

•

Our ADSs may be prohibited from trading in the United States under the HFCAA in the future if the PCAOB is unable to inspect or investigate completely auditors located in China. The delisting of the ADSs, or the threat of their being delisted, may materially and adversely affect the value of your investment;

•

The enactment of the Accelerating Holding Foreign Companies Accountable Act decreases the number of non-inspection years from three years to two, thus reducing the time period before our ADSs will be prohibited from trading on the Nasdaq Stock Market or in the over-the-counter market or delisted;

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•

The report and filing with the China Securities Regulatory Commission will be required in connection with the offering under this prospectus supplement, and, we cannot predict if we will be able to complete such report and filing process; and

•

Substantial uncertainties exist with respect to the interpretation and implementation of the Foreign Investment Law and how it may impact the viability of our current corporate structure, corporate governance and business operations.

Risks Related to Our Financial Prospects and Need for Additional Capital

Risks and uncertainties related to our financial prospects and need for additional capital include, but are not limited to, the following:

•

We have incurred net losses historically and we may continue to incur net losses in the near future;

•

We may need to obtain substantial additional financing to fund our growth and operations, which may not be available on acceptable terms, if at all;

•

Raising additional capital may lead to dilution of shareholdings by our existing shareholders and restrict our operations or require us to relinquish rights to our technologies or product candidates; and

•

We have certain shareholders who have board representation rights and their individual interests may differ from yours.

Risks Related to Clinical Development of Our Product Candidates

Risks and uncertainties related to clinical development of our product candidates include, but are not limited to, the following:

•

We may not be able to identify or discover new product candidates, and may allocate our limited resources to pursue a particular product candidate and fail to capitalize on product candidates that may later prove to be more profitable, or for which there is a greater likelihood of success;

•

We may not be successful in our efforts to use and expand our proprietary platforms to build a pipeline of product candidates;

•

Any failures or setbacks in our platforms or our other proprietary technologies could negatively affect our business and financial condition;

•

Our product candidates, for which we intend to seek approval as biologic products, may face competition sooner than anticipated; and

•

We depend substantially on the success of our product candidates, particularly our lead product candidate, ADG126 (muzastotug), which is in phase 1b/2 and phase 2 clinical studies, and our ability to advance and identify additional product candidates. Clinical trials of our product candidates may not be successful. If we are unable to successfully identify new product candidates, complete clinical development, obtain regulatory approval and commercialize our product candidates, or experience significant delays in doing so, our business will be materially harmed.

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Risks Related to Obtaining Regulatory Approval of Our Drug Candidates

Risks and uncertainties related to obtaining regulatory approval of our drug candidates include, but are not limited to, the following:

•

The regulatory approval processes of the FDA, NMPA and other comparable regulatory authorities are lengthy, time consuming and inherently unpredictable, and if we are ultimately unable to obtain regulatory approvals for our product candidates, our business will be substantially harmed.

•

Disruptions at the FDA and other government agencies caused by funding shortages or global health concerns could hinder their ability to hire, retain or deploy key leadership and other personnel, or otherwise prevent new or modified products from being developed, approved or commercialized in a timely manner or at all, which could negatively impact our business.

•

Even if we obtain FDA approval of any of our product candidates, we may never obtain approval or commercialize such products outside of the United States, which would limit our ability to realize their full market potential.

•

We are conducting clinical trials and may in the future conduct additional clinical trials for our product candidates outside the United States and/or China, and FDA, NMPA and similar foreign regulatory authorities may not accept data from such trial; and

•

Our product candidates may cause undesirable adverse events, side effects or have other properties that could delay or prevent their regulatory approval, limit the commercial profile of an approved label, or result in significant negative consequences following any regulatory approval.

Risks Related to Our Intellectual Property

Risks and uncertainties related to our intellectual property include, but are not limited to, the following:

•

It is difficult and costly to protect our proprietary rights and technology, and we may not be able to protect our intellectual property rights throughout the world;

•

Changes in patent law could diminish the value of patents in general, thereby impairing our ability to protect our product candidates;

•

We may not be successful in obtaining or maintaining necessary rights for our development pipeline through acquisitions and licensing deals;

•

We may become involved in lawsuits to protect or enforce our patents or other intellectual property, which could be expensive, time consuming and unsuccessful, and any unfavorable outcome from such litigation could limit our research and development activities and/or our ability to commercialize our product candidates; and

•

Our commercial success depends significantly on our ability to operate without infringing upon, misappropriating or otherwise violating the intellectual property rights of third parties.

Risks Related to the ADSs

Risks and uncertainties related to the ADSs include, but are not limited to, the following:

•

Our business and financial results, including our ability to raise capital or raise capital on favorable terms and the market price of our ADSs, may be adversely affected by the geopolitical factors arising in connection with Russia’s invasion of Ukraine, including particularly how countries like the United States and China choose to respond to this war. As a result, the value of our ADSs may significantly decline;

•

You may be subject to limitations on transfer of your ADSs;

•

The trading price of the ADSs is likely to be volatile, which could result in substantial losses to investors;

•

We are an emerging growth company within the meaning of the Securities Act and may take advantage of certain reduced reporting requirements;

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If securities or industry analysts cease to publish research or reports about our business, or if they adversely change their recommendations regarding the ADSs, the market price for the ADSs and trading volume could decline;

•

The sale or availability for sale, or perceived sale or availability for sale, of substantial amounts of the ADSs could adversely affect their market price; and

•

We were likely a passive foreign investment company, or PFIC, for 2025, and there is a significant risk that we will be a PFIC for 2026 and possibly subsequent taxable years, in which case U.S. investors will generally be subject to adverse U.S. federal income tax consequences.

PRC REGULATORY DEVELOPMENTS

Cybersecurity Review

On December 28, 2021, the Cyberspace Administration of China, or the CAC, and 12 other relevant PRC government authorities published the amended Cybersecurity Review Measures, or the Cybersecurity Review Measures, which went on February 15, 2022 and supersede and replace the current Cybersecurity Review Measures previously promulgated on April 13, 2020. The Cybersecurity Review Measures provide that the purchase of network products and services by a “critical information infrastructure operator” and the data processing activities of a “network platform operator” that affect or may affect national security shall be subject to the cybersecurity review. Furthermore, if a “network platform operator” that possesses personal information of more than one million users intends to go public in a foreign country, it must apply for a cybersecurity review with the Cybersecurity Review Office. In addition, the relevant PRC governmental authorities may initiate cybersecurity review if they determine certain network products, services, or data processing activities affect or may affect national security.

On September 24, 2024, the State Council published the Regulation on Network Data Security Management, which stipulates that a network data processor shall, in accordance with the provisions of applicable laws and administrative regulations and the compulsory requirements of national standards, and on the basis of graded cybersecurity protection, strengthen network data security protection, establish and improve network data security management rules. Where network data processing activities carried out by a network data processor affect or may affect national security, national security review shall be conducted in accordance with the relevant provisions issued. See “Item 4. Information of the Company — 4.B. Business Overview — Regulation — Other PRC Government Regulations — Regulations on Information Security and Data Protection” in our most recent annual report on Form 20-F incorporated by reference in this prospectus supplement for further discussion. As the Regulation on Network Data Security Management is relatively new, the specific implementation of it still remains uncertainties. In addition, under the Provisions on Promoting and Regulating Cross-border Flow of Data effective March 22, 2024, cross-border transfer of important data or personal information may be subject to security assessment, standard contract filing or certification depending on the volume and nature of data involved.

As advised by our PRC legal counsel, Jingtian & Gongcheng, given the nature of our business, since we do not possess or process personal information of more than one million users/individuals, and we do not believe we are a “critical information infrastructure operator,” “network platform operator” or a data processor whose purchase of network products and services or data processing activities affect or may affect national security, and we do not believe our current data processing activities trigger mandatory cybersecurity review requirements under applicable PRC laws and regulations, the listing of our ADSs on the Nasdaq and future potential offering of our ADSs will not be subject to the cybersecurity review process under the Cybersecurity Review Measures, although we cannot guarantee that the relevant PRC regulatory authority will agree with our interpretation. Currently, the Cybersecurity Review Measures and the Regulation on Network Data Security Management have not materially affected our business and operations, but in anticipation of the strengthened implementation of cybersecurity laws and regulations and the continued expansion of our business, we face potential risks if we are deemed as a critical information infrastructure operator, a network platform operator or data processing operator under the PRC cybersecurity laws and regulations. In such case, we must fulfill certain obligations as required under the PRC cybersecurity laws and regulations, including, among others, storing personal information and other important data collected and produced within the PRC territory as we advance our drug discovery pipelines as part of our future

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operations in China, and we may be subject to lengthy cybersecurity review, annual data security assessment and other enhanced regulatory requirements when purchasing network products and services or conducting other data processing activities. We may face challenges in addressing such enhanced regulatory requirements and be required to make necessary changes to our internal policies and practices in data privacy and cybersecurity matters. As advised by our PRC legal counsel, Jingtian & Gongcheng, as of the date of this prospectus supplement, although detailed implementation in specific sectors remains subject to further regulatory practice and interpretation, the PRC governmental authorities have broad discretion in the interpretation and enforcement of these laws and regulations. It also remains uncertain whether the future regulatory changes will impose additional restrictions on companies like us. We cannot predict the impact of the Cybersecurity Review Measures and/or the Regulation on Network Data Security Management, if any, at this stage, and we will closely monitor and assess any development in the rule-making process. If the future enacted laws and regulations, including the enacted version of the data security regulations mandate clearance of cybersecurity review and other specific actions to be completed by companies like us before we are able to complete this offering, we will face uncertainties as to whether such clearance and/or other specific actions can be timely obtained or completed, or at all. If we are not able to comply with the cybersecurity and data privacy requirements in a timely manner, or at all, we may be subject to government enforcement actions and investigations, fines, penalties, or suspension of our non-compliant operations, among other sanctions, which could materially and adversely affect our business and results of operations.

Any failure to complete the required cybersecurity review may result in administrative penalties, including fines, a shut-down of our business, revocation of requisite licenses, as well as reputational damage or legal proceedings or actions against us, which may have material adverse effects on our business, financial condition and results of operations. As of the date of this prospectus supplement, we have not been involved in any investigation on cybersecurity review made by the CAC on such basis, and we have not received any inquiry, notice, warning, or sanction in such respect, and we have not been subject to any material fines or other material penalties due to non-compliance with cybersecurity or data privacy laws or regulations. Our PRC legal counsel does not expect that, as of the date of this prospectus supplement, we are required to file an application for the cybersecurity review by CAC in connection with our previous issuance of securities to foreign investors or maintaining our listing status on Nasdaq. We have been making continuous efforts to comply with the relevant cybersecurity and data protection laws and regulations of the PRC, and will endeavor to comply with any updated applicable laws, regulations or guidelines as issued by any relevant regulatory authority in the PRC. See “Item 3 Key Information — 3.D. Risk Factors — Risks Related to Doing Business in the PRC — Failure to comply with existing or future laws and regulations related to privacy or data security could lead to government enforcement actions, which could include civil or criminal fines or penalties, investigation or sanction by regulatory authorities, private litigation, other liabilities, and/or adverse publicity” in our most recent annual report on Form 20-F incorporated by reference in this prospectus supplement.

Post-Offering CSRC Filings Required for the Offering of Our ADSs

On February 17, 2023, the China Securities Regulatory Commission, or CSRC, issued the Notice on Filing Arrangements for Overseas Securities Offering and Listing by Domestic Companies (the “CSRC Filing Notice”), stating that the CSRC has published the Trial Administrative Measures of Overseas Securities Offering and Listing by Domestic Companies (the “Trial Measures”) and supporting guidelines (the “Listing Guidelines”), collectively the Trial Measures and Listing Guidelines, which came into effect on March 31, 2023.

Under the Trial Measures and Listing Guidelines, subsequent securities offerings of an issuer in (i) the same overseas market where it has previously offered and listed securities, and (ii) an overseas market other than one where the issuer has previously offered and listed securities shall be (a) filed with the CSRC within three working days after offerings are completed, and (b) within three working days after the submission of the application documents for overseas issuance and listing, respectively. Further, the CSRC Filing Notice states that, beginning from March 31, 2023, PRC domestic enterprises which have already issued and listed securities overseas and fall within the scope of filing under the Trial Measures shall be considered “existing enterprises,” or Existing Listed Enterprises. Existing Listed Enterprises are not required to complete filings immediately; rather, Existing Listed Enterprises should complete filings if they are subsequently involved in matters require filings, such as follow-on financing activities, in accordance with the Trial Measures.

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As advised by our PRC legal counsel, Jingtian & Gongcheng, upon completion of the offering under this prospectus supplement, we shall file a post-closing filing report with CSRC within three (3) working days. We intend to comply with such requirements imposed by the Trial Measures and Listing Guidelines.

MATERIAL LICENSES AND APPROVALS

Our PRC subsidiary has obtained all material licenses and approvals required for our operations in China. For details of our material licenses and approvals, see “Item 4. Information of the Company — 4.B. Business Overview — Material Licenses and Approvals” in our most recent annual report on Form 20-F incorporated by reference in this prospectus supplement. For risks relating to licenses and approvals required for our operations in China, see “Item 3. Key Information — 3.D. Risk Factors — Risks Related to Doing Business in the PRC,” “— Risks Related to Clinical Development of Our Product Candidates,” and “— Risks Related to Obtaining Regulatory Approval of Our Drug Candidates” in our most recent annual report on Form 20-F incorporated by reference in this prospectus supplement.

Furthermore, in connection with our historical issuance of securities to foreign investors, under currently effective PRC laws, regulations and regulatory rules, as of the date of this prospectus supplement, we are not currently required to obtain permissions from the CSRC, and we have not received any formal notice from any PRC authority indicating that we should apply for or are otherwise subject to cybersecurity review or security assessment. In addition, we have not been asked to obtain such permissions by any PRC authority or received any denial to do so. However, the PRC government has recently indicated an intent to exert more oversight and control over offerings that are conducted overseas and/or foreign investment in China-based issuers. For example, the CSRC published the Trial Measures and Listing Guidelines on February 17, 2023, designed to regulate overseas securities offerings by PRC domestic companies. Given the recent nature of the introduction of the Trial Measures and Listing Guidelines, there remains significant uncertainty as to the enactment, interpretation and implementation of regulatory requirements related to overseas securities offerings and other capital markets activities.

If (i) we mistakenly conclude that certain regulatory filings, permissions and approvals are not required or (ii) applicable laws, regulations, or interpretations change and (iii) we are required to obtain such filings, permissions or approvals in the future, but fail to receive or maintain such filings, permissions or approvals, we may face sanctions by the CSRC, the Cyberspace Administration of China (the “CAC”) or other PRC regulatory agencies. In addition, rules and regulations in China can change quickly with little advance notice. These regulatory agencies may impose fines and penalties on our operations in China, limit our operations in China, limit our ability to pay dividends outside of China, limit our ability to list on stock exchanges outside of China or offer our securities to foreign investors or take other actions that could have a material adverse effect on our business, financial condition, results of operations and prospects, as well as the trading price of our securities. See also “Item 3 Key Information — 3.D.Risk Factors — Risks Related to Doing Business in the PRC — We may be required to obtain approval or complete filing or other requirements of the CSRC or other PRC government authorities in connection with our issuances of securities overseas, and, if required, we cannot predict whether we will be able to obtain such approval or complete such governmental procedure” in our most recent annual report on Form 20-F incorporated by reference in this prospectus supplement.

CORPORATE INFORMATION

Adagene was incorporated in the Cayman Islands in February 2011. We conduct our operations in the U.S. primarily through our U.S. subsidiary, Adagene Incorporated, and in China through Adagene Suzhou, which was incorporated in February 2012. The ADSs, each representing one and one quarter (1.25) of our Ordinary Shares, par value US$0.0001 per share, are currently traded on the Nasdaq under the symbol “ADAG”.

Our principal executive offices of our main operations are located at 4F, Building C14, No. 218, Xinghu Street, Suzhou Industrial Park Suzhou, Jiangsu Province, 215123, People’s Republic of China. Our San Diego office address is 6048 Cornerstone Court West, Suite C, San Diego, CA 92121. Our registered office is located at Vistra (Cayman) Limited, P. O. Box 31119 Grand Pavilion, Hibiscus Way, 802 West Bay Road, Grand Cayman, KY1 — 1205 Cayman Islands. Our telephone number is +86-512-8777-3632. Investors should contact us for any inquiries through the address and telephone number of our principal executive office. Our corporate website is www.adagene.com. The reference to our website is an inactive textual

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reference only, and information contained therein or connected thereto is not incorporated into this prospectus supplement or the registration statement of which it forms a part.

IMPLICATIONS OF BEING AN “EMERGING GROWTH COMPANY”

We qualify as an “emerging growth company” as defined in the Jumpstart our Business Startups Act of 2012 (the “JOBS Act”). As an emerging growth company, we may take advantage of specified reduced reporting and other burdens that are otherwise applicable generally to public companies. These provisions include:

•

an exemption from the auditor attestation requirement in the assessment of our internal control over financial reporting pursuant to Section 404 of the Sarbanes-Oxley Act of 2002 (the “Sarbanes- Oxley Act”); and

•

to the extent that we no longer qualify as a foreign private issuer, (i) reduced disclosure obligations regarding executive compensation in our periodic reports and proxy statements and (ii) exemptions from the requirements of holding a non-binding advisory vote on executive compensation, including golden parachute compensation.

We may take advantage of these provisions for up to five years or such earlier time that we are no longer an emerging growth company. We will remain an emerging growth company until the earliest of the last day of the fiscal year in which we have total annual gross revenues of at least US$1.235 billion; the last day of our fiscal year following the fifth anniversary of the completion of our initial public offering; (iii) the date on which we have issued more than US$1.0 billion in non-convertible debt during the previous three years; or (iv) the date on which we are deemed to be a large accelerated filer under the rules of the SEC, which means the market value of our Ordinary Shares that are held by non-affiliates equals or exceeds US$700.0 million as of the last business day of our most recently completed second fiscal quarter. We may choose to take advantage of some but not all of these reduced burdens. For example, Section 107 of the JOBS Act also provides that an emerging growth company can take advantage of an extended transition period for complying with new or revised accounting standards applicable to public companies. This provision allows an emerging growth company to delay the adoption of certain accounting standards until those standards would otherwise apply to private companies. We have decided not to “opt out” of such exemptions afforded to an emerging growth company.

IMPLICATIONS OF BEING A FOREIGN PRIVATE ISSUER

We are also considered as a “foreign private issuer.” Accordingly, we report under the Exchange Act of 1934, as amended (the “Exchange Act”), as a non-U.S. company with foreign private issuer status. This means that, even after we no longer qualify as an emerging growth company, as long as we qualify as a foreign private issuer under the Exchange Act, we will be exempt from certain provisions of the Exchange Act that are applicable to U.S. domestic public companies, including:

•

the sections of the Exchange Act regulating the solicitation of proxies, consents or authorizations in respect of a security registered under the Exchange Act; and

•

the rules under the Exchange Act requiring the filing with the Securities and Exchange Commission, or SEC, of quarterly reports on Form 10-Q containing unaudited financial and other specified information, or current reports on Form 8-K, upon the occurrence of specified significant events.

We may take advantage of these exemptions until such time as we are no longer a foreign private issuer. We would cease to be a foreign private issuer at such time as more than 50% of our outstanding voting securities are held by U.S. residents and any of the following three circumstances applies: (i) the majority of our executive officers or directors are U.S. citizens or residents, (ii) more than 50% of our assets are located in the United States or (iii) our business is administered principally in the United States.

In this prospectus supplement and in the documents incorporated by reference in this prospectus supplement, we have taken advantage of certain of the reduced reporting requirements as a result of being an emerging growth company and a foreign private issuer. Accordingly, the information contained in this prospectus supplement and in the documents incorporated by reference in this prospectus supplement may be different than the information you receive from other public companies in which you hold equity securities.

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THE OFFERING

ADSs offered by us

18,666,000 ADSs, representing 23,332,500 Ordinary Shares

Ordinary Shares to be outstanding immediately after this offering Ordinary Shares

82,564,493 Ordinary Shares

Use of proceeds

We estimate that the net proceeds from this offering will be approximately US$65.3 million, after deducting the underwriting discount and estimated offering expenses payable by us.

We intend to use the net proceeds from this offering to fund research and development activities on our pipeline candidates, including ADG126, ADG 138 and other programs, and for general corporate purposes. See “Use of Proceeds.”

Lock-up

In connection with this offering, subject to certain exceptions, we and our officers and directors, have agreed with the underwriters, without the prior written consent of the representatives, not to offer, pledge, sell, or otherwise transfer or dispose of any shares of our share capital or securities convertible into or exchangeable or exercisable for any shares of our share capital during the period ending 60 days after the date of this prospectus supplement.

Nasdaq Global Market Symbol

“ADAG”

Payment and settlement

The underwriters expect to deliver the ADSs against payment therefor on or about April 6, 2026.

Depositary

JPMorgan Chase Bank, N.A.

Risk factors

Investing in our securities involves a high degree of risk. See “Risk Factors” beginning on page S-15 of this prospectus and the other information included in, or incorporated by reference into, this prospectus for a discussion of certain factors that you should carefully consider before deciding to invest in shares of our Ordinary Shares or ADSs.

In this prospectus supplement, unless otherwise indicated, the number of shares of Ordinary Shares shown above to be outstanding immediately following this offering is based on 59,231,993 Ordinary Shares outstanding as of December 31, 2025 and excludes

•

1,582,460 Ordinary Shares underlying the outstanding equity awards granted under the 2019 Plan as of December 31, 2025,

•

11,747,957 Ordinary Shares underlying the outstanding equity awards granted under the 2021 Plan as of December 31, 2025,

•

1,000,000 outstanding warrants, representing right to purchase 1,000,000 ordinary shares; and

•

1,062,500 Series A non-voting convertible preferred shares, convertible into 10,625,000 ordinary shares.

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RISK FACTORS

Investment in any securities offered pursuant to this prospectus supplement and the accompanying base prospectus involves risks. You should carefully consider the risk factors described below and in our annual report on Form 20-F for the year ended December 31, 2025, incorporated by reference in this prospectus supplement, any amendment or update thereto reflected in subsequent filings with the SEC, including in our annual reports on Form 20-F, and all other information contained or incorporated by reference in this prospectus supplement, as updated by our subsequent filings under the Exchange Act. In general, investing in the securities of issuers in emerging market countries such as the PRC involves certain risks not typically associated with investing in securities of U.S. companies. You should pay special attention to subsections headed “Recent Regulatory Developments,” “Holding Company Structure,” and “Risks Related to Doing Business in the PRC” in our most recent annual report on Form 20-F incorporated by reference. The risks and uncertainties we have described are not the only ones we face. Additional risks and uncertainties not presently known to us or that we currently deem immaterial may also affect our operations. The occurrence of any of these risks might cause you to lose all or part of your investment in the offered securities.

Risks Related to This Offering

If you purchase the ADSs sold in this offering, you will experience immediate and substantial dilution in the net tangible book value of your ADSs. In addition, we may issue additional equity or debt securities in the future, which may result in additional dilution to you.

The price per ADS being offered is be higher than the net tangible book value per ADS prior to this offering. As a result, investors purchasing ADSs in this offering will pay a price per ADS that substantially exceeds the value of our tangible assets after subtracting liabilities. Based upon the public offering price of US$3.75 per ADS, new investors will incur immediate dilution of US$2.23 per ADS based on the net tangible book value as of December 31, 2025. For a more detailed discussion of the foregoing, see the section titled “Dilution” below. To the extent outstanding stock options are exercised or outstanding restricted share units are vested, there will be further dilution to new investors. In addition, to the extent we need to raise additional capital in the future and we issue additional Ordinary Shares or securities convertible or exchangeable for our Ordinary Shares, our then existing shareholders may experience dilution and the new securities may have rights senior to those of the ADSs offered in this offering. After this offering is completed, our effective Registration Statement on Form F-3 will remain available to cover the future public offering and our existing “at-the-market offering” program.

We have broad discretion over the use of the net proceeds from this offering and may not use them effectively or in a manner desired by our investors.

Our management will have broad discretion in the application of the net proceeds from this offering, including for any of the purposes described in the section entitled “Use of Proceeds,” and you will not have the opportunity as part of your investment decision to assess whether the net proceeds are being used appropriately. Because of the number and variability of factors that will determine our use of the net proceeds from this offering, their ultimate use may vary substantially from their currently intended use. Our management might not apply our net proceeds in ways that ultimately increase the value of your investment. We expect to use the net proceeds from this offering to fund research and development activities on our pipeline candidates, including ADG126, ADG 138 and other programs, and for general corporate purposes. The failure by our management to apply these funds effectively could harm our business. Pending their use, we plan to invest the net proceeds from this offering in short-and intermediate-term, interest-bearing obligations, investment-grade instruments, certificates of deposit or direct or guaranteed obligations of the U.S. government. These investments may not yield a favorable return to our shareholders. If we do not invest or apply the net proceeds from this offering in ways that enhance shareholder value, we may fail to achieve expected financial results, which could cause the price of ADSs to decline.

Future sales or issuances of ADSs in the public markets, or the perception of such sales, could depress the trading price of the ADSs.

The sale of a substantial number of ADSs or other equity-related securities in the public markets, or the perception that such sales could occur, could depress the market price of the ADSs and impair our

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ability to raise capital through the sale of additional equity securities. We may sell large quantities of ADSs at any time pursuant to this prospectus supplement or in one or more separate offerings. We cannot predict the effect that future sales of ADSs, Ordinary Shares or other equity-related securities would have on the market price of the ADSs.

The report and filing with the China Securities Regulatory Commission will be required in connection with the offering under this prospectus supplement and our future offerings, and, we cannot predict if we will be able to complete such report and filing process in a timely manner, or at all.

As advised by our PRC legal counsel, Jingtian & Gongcheng, upon completion of the offering under this prospectus supplement, we shall file post-closing filing report with CSRC within three (3) working days. We intend to comply with such requirements imposed by the Trial Measures and Listing Guidelines. We cannot assure you that we will be able to address the comments from the CSRC, if any, in connection with our filing in a timely and satisfactory manner. Furthermore, any of our future offering and listing of our securities in an overseas market shall be subject to the filing requirements under the Trial Measures and Listing Guidelines. We may face adverse actions or sanctions by the CSRC or other PRC regulatory agencies if we are unable to comply with such requirements, which may result in fines and penalties, restrictions on our operations, having to delist from a stock exchange outside of China, the halting of securities offerings to foreign investors and other actions that could materially and adversely affect our operations and the interest of our investors and cause a significant depreciation in the price of our ordinary shares and ADSs.

We were likely a passive foreign investment company, or PFIC, for 2025 and certain prior taxable years, if the value of our goodwill is determined by reference to the average of our quarterly market capitalization, and there is a significant risk that we will be a PFIC for 2026 and possibly subsequent taxable years, in which case U.S. investors will generally be subject to adverse U.S. federal income tax consequences.

In general, a non-U.S. corporation will be a PFIC for any taxable year in which (i) 75% or more of its gross income consists of passive income, or the income test, or (ii) 50% or more of the average value of its assets (generally determined on a quarterly basis) consists of assets that produce, or are held for the production of, passive income, or the asset test. For purposes of the above calculations, a non-U.S. corporation that directly or indirectly owns at least 25% by value of the ordinary shares of another corporation is treated as if it held its proportionate share of the assets of the other corporation and received directly its proportionate share of the income of the other corporation. Passive income generally includes interest, dividends, gains from certain property transactions, rents and royalties (other than certain rents or royalties derived in the active conduct of a trade or business). Cash is generally a passive asset for PFIC purposes. Goodwill and other intangible assets are active assets under the PFIC rules to the extent attributable to activities that produce active income.

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The assets shown on our balance sheet are expected to consist primarily of cash and cash equivalents for the foreseeable future. Therefore, whether we will satisfy the asset test for any taxable year will depend largely on the value of our goodwill and other intangible assets and on how quickly we utilize the cash in our business. The value of our goodwill and other intangible assets for any taxable year may be determined in large part by reference to the average of our market capitalization for that year. Because our market capitalization has declined substantially in recent years, if the value of our goodwill and other intangible assets is determined by reference to the average of our quarterly market capitalization, then we were likely a PFIC for our 2025 taxable year and certain of our prior taxable years. For similar reasons, there is a significant risk that we will also be a PFIC for 2026 and possibly future taxable years. In addition, the extent to which our goodwill and other intangible assets should be characterized as a non-passive asset is not entirely clear. We have not obtained any valuation of our assets (including our goodwill and other intangible assets). U.S. investors in our ADSs or ordinary shares should consult their tax advisors regarding the value and characterization of our assets for purposes of the PFIC rules, which are subject to some uncertainties. In addition, we can give no assurance that we will not be a PFIC under the income test for any taxable year, particularly prior to the commercialization of any of our drug candidates (since certain items of active income that we may earn for any taxable year prior to the commercialization of any drug candidate may be non-recurring or conditional).

If we are a PFIC for any taxable year during which a U.S. investor owns our ADSs or ordinary shares, the U.S. investor generally will be subject to adverse U.S. federal income tax consequences, including increased tax liability on disposition gains and “excess distributions,” and additional reporting requirements. This will generally continue to be the case even if we ceased to be a PFIC in a later taxable year, unless certain elections are made. See “Taxation — Material U.S. Federal Income Tax Consequences” below.

If a U.S. person owns, directly or indirectly, our ADSs or ordinary shares and is treated as owning 10% or more of our stock by vote or value, such person may be subject to adverse U.S. federal income tax consequences.

If a U.S. person is treated as owning (directly, indirectly or constructively) 10% or more of our stock (including our ADSs and ordinary shares) by value or voting power, such person generally will be treated as a “United States shareholder” with respect to each “controlled foreign corporation,” or CFC, in our group. A CFC is a non-U.S. corporation more than 50% of the stock (by voting power or value) of which is owned (directly, indirectly or constructively) by “United States shareholders.” We have not determined whether we are a CFC. However, even if we are not a CFC, under certain ownership attribution rules our non-U.S. subsidiaries would be treated as owned by our U.S. subsidiary and thus may be treated as CFCs. A United States shareholder that owns stock of a CFC directly or indirectly may be subject to additional U.S. federal income tax liabilities and reporting requirements. We do not intend to furnish any information that may be necessary for United States shareholders, if any, to comply with the CFC rules. U.S. investors that own our ADSs or ordinary shares directly or indirectly and may be treated for purposes of the CFC rules as owning 10% of our stock by voting power or value should consult their tax advisors regarding the potential application of these rules in their particular circumstances.

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USE OF PROCEEDS

We estimate that the net proceeds from this offering will be approximately US$65.3 million, after deducting the underwriting discount and estimated offering expenses payable by us.

We intend to use the net proceeds from this offering, together with our other cash resources, primarily to fund research and development activities on our pipeline candidates, including ADG126, ADG 138 and other programs, and for general corporate purposes, which may include additions to working capital.

The amounts and timing of our actual expenditures will depend on numerous factors, including the progress of our clinical trials and other development efforts and other factors described under “Risk Factors” in this prospectus supplement, the accompanying base prospectus and the documents incorporated by reference herein and therein, as well as the amount of cash used in our operations. We may find it necessary or advisable to use the net proceeds for other purposes, and we will have broad discretion in the application of the net proceeds.

Pending the use of the net proceeds described above, we plan to invest the net proceeds from this offering in a variety of capital preservation investments, including short- and intermediate-term, interest-bearing obligations, investment-grade instruments, certificates of deposit or direct or guaranteed obligations of the U.S. government.

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DIVIDEND POLICY

We have not previously declared or paid cash dividends and we have no plan to declare or pay any dividends in the near future on our Ordinary Shares or the ADSs representing our Ordinary Shares. We currently intend to retain most, if not all, of our available funds and any future earnings to operate and expand our business.

We are a holding company incorporated in the Cayman Islands. In the future, we may rely on dividends from our subsidiaries, including our U.S. and PRC subsidiaries, for our cash requirements, including any payment of dividends to our shareholders. PRC regulations may restrict the ability of our PRC subsidiary to pay dividends to us. See “Item 4 Information of the Company — B. Business Overview — Regulation — Regulations relating to Dividend Distribution” in our most recent annual report on Form 20-F incorporated by reference.

Our board of directors has discretion as to whether to distribute dividends, subject to certain requirements of Cayman Islands law. In addition, our shareholders may, subject to the provisions of our post- offering articles of association, by ordinary resolution declare a dividend, but no dividend may exceed the amount recommended by our board of directors. Under Cayman Islands law, a Cayman Islands company may pay a dividend out of either profit, retained earnings or share premium account, provided that in no circumstances may a dividend be paid if this would result in the company being unable to pay its debts as they fall due in the ordinary course of business. Even if our board of directors decides to pay dividends, the form, frequency and amount will depend upon our future operations and earnings, capital requirements and surplus, general financial condition, contractual restrictions and other factors that the board of directors may deem relevant. If we pay any dividends on our Ordinary Shares, we will pay those dividends which are payable in respect of the Ordinary Shares underlying the ADSs to the depositary, as the registered holder of such Ordinary Shares, and the depositary then will pay such amounts to the ADS holders in proportion to the Ordinary Shares underlying the ADSs held by such ADS holders, subject to the terms of the deposit agreement, including the fees and expenses payable thereunder. See “Item 12 Description of Securities Other Than Equity Securities — D. American Depositary Shares” in our most recent annual report on Form 20-F incorporated by reference.

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CAPITALIZATION

The following table sets forth our capitalization as of December 31, 2025, the latest date for which we have audited financial statements:

•

on an actual basis;

•

on an as adjusted basis to give effect to the issuance and sale of ADSs in this offering, after deducting estimated offering expenses payable by us.

The as adjusted information below is illustrative only. You should read this table together with our audited consolidated financial statements and the related notes and “Item 5. Operating and Financial Review and Prospects” in our most recent annual report on Form 20-F, which is incorporated by reference in this prospectus supplement.

	As of December 31, 2025
	Actual		As adjusted
	US$’000
Cash and cash equivalents		74,524		139,821
Current portion of long-term borrowings		711		711
Long-term borrowings		1,138		1,138
Mezzanine equity
Series A non-voting contingently redeemable convertible preferred shares (par value of US$0.0001 per share, 1,062,500 shares authorized, issued and outstanding as of December 31, 2025)		16,550		16,550
Shareholders’ equity
Ordinary shares (par value of US$0.0001 per share; 640,000,000 shares authorized, and 59,231,993 shares issued and outstanding as of December 31, 2025)		6		8
Additional paid-in capital		366,043		431,339
Accumulated other comprehensive income		(1,915)		(1,915)
Accumulated deficit		(328,785)		(328,785)
Total mezzanine equity and shareholders’ equity		51,900		117,197
Total capitalization		53,749		119,047

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DILUTION

If you invest in our Ordinary Shares and/or ADSs in this offering, your ownership interest will be diluted immediately to the extent of the difference between the price you pay in this offering and the net tangible book value per Ordinary Share after this offering.

Our net tangible book value as of December 31, 2025 was approximately US$35.16 million, or US$0.59 per Ordinary Shares, based on 59,231,993 Ordinary Shares then outstanding. After giving effect to this offering of 18,666,000 ADS at the offering price of US$3.75 per ADS and after deducting the estimated underwriting discount and estimated offering expenses payable by us, our net tangible book value at December 31, 2025 would have been approximately US$100.5 million, or US$1.22 per Ordinary Share. This represents an immediate increase in net tangible book value of US$0.62 per Ordinary Share to existing shareholders and an immediate dilution of US$1.78 per Ordinary Share to investors in this offering. The following table illustrates this per share dilution. The as adjusted information is illustrative only and will adjust based on the actual price to the investors, the actual number of shares sold and other terms of the offering determined at the time our ADSs are sold pursuant to this prospectus supplement.

Per Ordinary
Share

Per ADS

Initial public offering price per ADS

US$

3.00

US$

3.75

Net tangible book value per share as of December 31, 2025

US$

0.59

US$

0.74

Increase in net tangible book value per share to existing shareholders

US$

0.62

US$

0.78

As adjusted net tangible book value per share after giving effect to this offering

US$

1.22

US$

1.52

Dilution per share to new investors

US$

1.78

US$

2.23

The above discussion and table are based on our actual Ordinary Shares outstanding as of December 31, 2025. The discussion and tables above also assume (i) no exercise of any awards outstanding as of the date of this prospectus, (ii) no exercise of 1,000,000 outstanding warrants, representing right to purchase 1,000,000 ordinary shares, and (iii) no conversion of 1,0625,000 Series A non-voting convertible preferred shares into 10,625,000 ordinary shares.

As of December 31, 2025, the aggregate number of our ordinary shares underlying our outstanding awards under the 2019 Plan was 1,582,460. As of December 31, 2025, we have granted 11,747,957 shares awards under the 2021 Plan, excluding awards that were forfeited, cancelled or exercised after the relevant grant dates. The weighted average exercise price of awards under the 2019 Plan and 2021 Plan was US$4.61 and US$1.73 per Ordinary Share, respectively, excluding awards that were forfeited, cancelled or exercised after the relevant grant dates. To the extent that outstanding options are exercised, you will experience further dilution. In addition, we may choose to raise additional capital due to market conditions or strategic considerations even if we believe we have sufficient funds for our current or future operating plans. To the extent that additional capital is raised through the sale of equity or convertible debt securities, the issuance of such securities may result in further dilution to our shareholders.

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TAXATION

The following discussion of Cayman Islands, PRC and United States federal income tax consequences of an investment in the ADSs or Ordinary Shares is based upon laws and relevant interpretations thereof in effect as of the date of this prospectus supplement, all of which are subject to change. This discussion does not deal with all possible tax consequences relating to an investment in the ADSs or Ordinary Shares, such as the tax consequences under U.S. state, or local laws or the tax laws of any jurisdiction other than the Cayman Islands, the PRC and the United States. To the extent that the discussion relates to matters of Cayman Islands tax law, it represents the opinion of Walkers (Hong Kong), our Cayman Islands counsel. To the extent that the discussion relates to matters of PRC tax law, it represents the opinion of Jingtian & Gongcheng, our PRC legal counsel.

Cayman Islands Taxation

According to Walkers (Hong Kong), our Cayman Islands counsel, the Cayman Islands currently levies no taxes on individuals or corporations based upon profits, income, gains or appreciation, and there is no taxation in the nature of inheritance tax or estate duty. There are no other taxes likely to be material to us or holders of our ADSs or Ordinary Shares levied by the government of the Cayman Islands, except for stamp duties which may be applicable on instruments executed in, or after execution brought within the jurisdiction of the Cayman Islands. The Cayman Islands is not party to any double tax treaties that are applicable to any payments made to or by our company. There are no exchange control regulations or currency restrictions in the Cayman Islands.

Payments of dividends and capital in respect of the ADSs or Ordinary Shares will not be subject to taxation in the Cayman Islands and no withholding will be required on the payment of a dividend or capital to any holder of the ADSs or Ordinary Shares, nor will gains derived from the disposal of the ADSs or Ordinary Shares be subject to Cayman Islands income or corporation tax.

Material PRC Income Tax Considerations

According to Jingtian & Gongcheng, our PRC legal counsel, under the PRC EIT Law, which became effective on January 1, 2008 and was amended on December 29, 2018, an enterprise established outside the PRC with “de facto management bodies” within the PRC is considered a “resident enterprise” for PRC enterprise income tax purposes and is generally subject to a uniform 25% enterprise income tax rate on its worldwide income. Under the implementation rules to the PRC EIT Law, a “de facto management body” is defined as a body that has material and overall management and control over the manufacturing and business operations, personnel and human resources, finances and properties of an enterprise.

In addition, the SAT Circular 82 issued by the SAT in April 2009 specifies that certain offshore incorporated enterprises controlled by PRC enterprises or PRC enterprise groups will be classified as PRC resident enterprises if the following are located or resident in the PRC: (a) senior management personnel and departments that are responsible for daily production, operation and management; (b) financial and personnel decision-making bodies; (c) key properties, accounting books, company seal, minutes of board meetings and shareholders’ meetings; and (d) half or more of the senior management or directors having voting rights. Further to SAT Circular 82, the SAT issued the SAT Bulletin 45, which took effect in September 2011, to provide more guidance on the implementation of SAT Circular 82. SAT Bulletin 45 provides for procedures and administration details of determination on resident status and administration on post-determination matters. Our company is a company incorporated outside the PRC. As a holding company, its key assets are its ownership interests in its subsidiaries, and its key assets are located, and its records (including the resolutions of its board of directors and the resolutions of its shareholders) are maintained, outside the PRC. As such, we do not believe that our company meets all of the conditions above or is a PRC resident enterprise for PRC tax purposes. For similar reasons, we believe our other entities outside China are not PRC resident enterprises either. However, the tax resident status of an enterprise is subject to determination by the PRC tax authorities and uncertainties remain with respect to the interpretation of the term “de facto management body.” There can be no assurance that the PRC government will ultimately take a view that is consistent with us. If the PRC tax authorities determine that our Cayman Islands holding company is a PRC resident enterprise for PRC enterprise income tax purposes, a number of unfavorable PRC tax consequences could follow. For example, a 10% withholding tax would be imposed

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on dividends we pay to our non-PRC enterprise shareholders (including our ADS holders). In addition, nonresident enterprise shareholders (including our ADS holders) may be subject to PRC tax on gains realized on the sale or other disposition of ADSs or Ordinary Shares, if such income is treated as sourced from within the PRC. Furthermore, if we are deemed a PRC resident enterprise, dividends paid to our non-PRC individual shareholders (including our ADS holders) and any gain realized on the transfer of ADSs or Ordinary Shares by such shareholders may be subject to PRC tax at a rate of 20% (which, in the case of dividends, may be withheld at source by us). These rates may be reduced by an applicable tax treaty, but it is unclear whether in practice non-PRC shareholders of our company would be able to obtain the benefits of any tax treaties between their country of tax residence and the PRC in the event that we are treated as a PRC resident enterprise.

Material U.S. Federal Income Tax Considerations

The following discussion describes U.S. federal income tax consequences to the U.S. Holders described below of the ownership and disposition of the ADSs or ordinary shares. This discussion is not a comprehensive description of all of the tax considerations that may be relevant to your decision to hold the ADSs or ordinary shares. This discussion applies to you only if you are a U.S. Holder that acquires the ADSs in this offering and holds them or the underlying ordinary shares as capital assets for U.S. federal income tax purposes. In addition, it does not describe all of the tax consequences that may be relevant in light of your particular circumstances, including the any minimum tax, the Medicare contribution tax on net investment income, and tax consequences applicable to you if you are subject to special rules, such as:

•

one of certain financial institutions;

•

a dealer or trader in securities that uses a mark-to-market method of tax accounting;

•

a person holding ADSs or ordinary shares as part of a straddle, conversion transaction, integrated transaction or similar transaction;

•

a person whose functional currency for U.S. federal income tax purposes is not the U.S. dollar;

•

an entity classified as a partnership for U.S. federal income tax purposes (and investors therein);

•

a tax-exempt entity, “individual retirement account” or “Roth IRA”;

•

a person that owns or is deemed to own at any time 10% or more of our stock by vote or value; or

•

a person holding ADSs or ordinary shares in connection with a trade or business conducted outside the United States.

If you are a partnership for U.S. federal income tax purposes, the U.S. federal income tax consequences to your partners will generally depend on their status and your activities. Partnerships holding ADSs or ordinary shares and their partners should consult their tax advisors as to the particular U.S. federal income tax consequences of acquiring, owning or disposing of the ADSs or ordinary shares.

This discussion is based on the Internal Revenue Code of 1986, as amended, or the Code, administrative pronouncements, judicial decisions and final, temporary and proposed Treasury regulations, and the income tax treaty between the United States and the PRC, or the Treaty, all as of the date hereof, any of which is subject to change, possibly with retroactive effect.

For purposes of this discussion, you are a “U.S. Holder” if you are eligible for the benefits of the Treaty and are, for U.S. federal income tax purposes, a beneficial owner of ADSs or ordinary shares and:

•

a citizen or individual resident of the United States;

•

a corporation or other entity taxable as a corporation for U.S. federal income tax purposes, created or organized in or under the laws of the United States, any state therein or the District of Columbia; or

•

an estate or trust the income of which is subject to U.S. federal income taxation regardless of its source.

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In general, if you own ADSs you will be treated as the owner of the underlying ordinary shares represented by those ADSs for U.S. federal income tax purposes. Accordingly, no gain or loss will be recognized if you exchange ADSs for the underlying ordinary shares represented by those ADSs.

Passive Foreign Investment Company Rules

As discussed in certain of our Annual Reports on Form 20-F, we were likely a PFIC for 2025 and certain prior taxable years. In general, a non-U.S. corporation will be a passive foreign investment company, or a PFIC, for any taxable year in which (i) 75% or more of its gross income consists of passive income, or the income test, or (ii) 50% or more of the average value of its assets (generally determined on a quarterly basis) consists of assets that produce, or are held for the production of, passive income, or the asset test. For purposes of the above calculations, a non-U.S. corporation that directly or indirectly owns at least 25% by value of the ordinary shares of another corporation is treated as if it held its proportionate share of the assets of the other corporation and received directly its proportionate share of the income of the other corporation. Passive income generally includes interest, dividends, gains from certain property transactions, rents and royalties (other than certain rents or royalties derived in the active conduct of a trade or business). Cash is generally a passive asset for PFIC purposes. Goodwill and other intangible assets are active assets under the PFIC rules to the extent attributable to activities that produce active income.

The value of our goodwill and other intangible assets for any taxable year may be determined in large part by reference to the average of our market capitalization for that year. Because our market capitalization has declined substantially in recent years, if the value of our goodwill and other intangible assets is determined by reference to the average of our quarterly market capitalization then we were likely a PFIC for our 2025 taxable year and certain prior taxable years. For similar reasons, there is a significant risk that we will also be a PFIC for 2026 and possibly future taxable years. In addition, the extent to which our goodwill and other intangible assets should be characterized as a non-passive asset is not entirely clear. We have not obtained any valuation of our assets (including our goodwill and other intangible assets). U.S. Holders of our ADSs or ordinary shares should consult their tax advisors regarding the value and characterization of our assets for purposes of the PFIC rules, which are subject to some uncertainties. In addition, we can give no assurance that we will not be a PFIC under the income test for any taxable year particularly prior to the commercialization of our drug candidates (since certain items of active income that we may earn for any taxable year prior to the commercialization of any drug candidate may be non-recurring or conditional).

If we are a PFIC for any taxable year and any of our subsidiaries is also a PFIC (any such entity, a “Lower-tier PFIC”), U.S. Holders will be deemed to own a proportionate amount (by value) of the shares of each Lower-tier PFIC and will be subject to U.S. federal income tax according to the rules described in the subsequent paragraph on (i) certain distributions by a Lower-tier PFIC and (ii) dispositions of shares of Lower-tier PFICs, in each case as if the U.S. Holders held such shares directly, even though the U.S. Holders will not receive the proceeds of those distributions or dispositions.

In general, if we are a PFIC for any taxable year during which a U.S. Holder holds our ADSs or ordinary shares, gain recognized by such U.S. Holder on a sale or other disposition (including certain pledges) of its ADSs or ordinary shares will be allocated ratably over that U.S. Holder’s holding period. The amounts allocated to the taxable year of the sale or disposition and to any year before we became a PFIC will be taxed as ordinary income. The amount allocated to each other taxable year will be subject to tax at the highest rate in effect for individuals or corporations, as appropriate, for that taxable year, and an interest charge will be imposed on the resulting tax liability for each such year. Furthermore, to the extent that distributions received by a U.S. Holder in any taxable year on its ADSs or ordinary shares exceed 125% of the average of the annual distributions on the ADSs or ordinary shares received during the preceding three taxable years or the U.S. Holder’s holding period, whichever is shorter, the excess distributions will be subject to taxation in the same manner.

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Under a rule commonly referred to as the “once a PFIC, always a PFIC” rule, if we are a PFIC for any taxable year during which a U.S. Holder owns our ADSs or ordinary shares, we will generally continue to be treated as a PFIC with respect to the U.S. Holder for all succeeding taxable years during which the U.S. Holder owns the ADSs or ordinary shares, even if we cease to meet the threshold requirements for PFIC status. If we are a PFIC for any taxable year but cease to be PFIC for subsequent years, U.S. Holders should consult their tax advisors regarding the advisability of making a “deemed sale” election that will allow them to eliminate the continuing PFIC status under certain circumstances, but may require them to recognize gain taxed under the general PFIC rules described in the preceding paragraph.

Alternatively, if we are a PFIC and if the ADSs are “regularly traded” on a “qualified exchange” within the meaning of the Code, a U.S. Holder of ADSs may make a mark-to-market election that will result in tax treatment different from the general tax treatment for PFICs described above. The ADSs will be treated as “regularly traded” for any calendar year in which more than a de minimis quantity of the ADSs are traded on a qualified exchange on at least 15 days during each calendar quarter. The Nasdaq Global Market, where the ADSs are listed, is a qualified exchange for this purpose, but there is no assurance that our ADSs will be treated as regularly traded for any relevant period. If a U.S. Holder makes the mark-to-market election, the U.S. Holder generally will recognize as ordinary income any excess of the fair market value of the ADSs at the end of each taxable year over their adjusted tax basis, and will recognize an ordinary loss in respect of any excess of the adjusted tax basis of the ADSs over their fair market value at the end of the taxable year (but only to the extent of the net amount of income previously included as a result of the mark-to-market election). If a U.S. Holder makes the election, the U.S. Holder’s tax basis in the ADSs will be adjusted to reflect the income or loss amounts recognized. Any gain recognized on the sale or other disposition of ADSs in a taxable year in which we are a PFIC will be treated as ordinary income, and any loss will be treated as an ordinary loss (but only to the extent of the net amount of income previously included as a result of the mark-to-market election, with any excess treated as capital loss). If a U.S. Holder makes the mark-to-market election, distributions paid on ADSs will be treated as discussed under “— Taxation of Distributions” below (but subject to the discussion in the immediately subsequent paragraph). U.S. Holders should consult their tax advisors regarding the availability and advisability of making a mark-to-market election in their particular circumstances. In particular, U.S. Holders should consider carefully the impact of a mark-to-market election with respect to their ADSs because we may have Lower-tier PFICs for which a mark-to-market election likely cannot be made.

The favorable tax rates for dividends paid to certain non-corporate U.S. Holders of ADSs, which are discussed below, do not apply to dividends from a corporation that is a PFIC (or is treated as a PFIC with respect to a U.S. Holder) in the year the dividend is paid or the preceding year. We do not intend to provide information necessary for U.S. Holders to make a “qualified electing fund election,” which, if available, would result in tax treatment different from the tax treatment for PFICs described above.

If we are a PFIC for any taxable year during which a U.S. Holder owns any ADSs or ordinary shares, the U.S. Holder will generally be required to file annual reports with the Internal Revenue Service (the “IRS”). U.S. Holders should consult their tax advisors regarding the PFIC rules and their application.

Taxation of Distributions

The following is subject to the discussion under “— Passive Foreign Investment Company Rules” above.

Distributions paid on ADSs or ordinary shares, other than certain pro rata distributions of ordinary shares, will generally be treated as dividends to the extent paid out of our current or accumulated earnings and profits (as determined under U.S. federal income tax principles). Because we do not maintain calculations of our earnings and profits under U.S. federal income tax principles, we expect that any distributions will be reported to you as dividends. Dividends from us will not be eligible for the dividends-received deduction generally available to U.S. corporations under the Code. Subject to applicable limitations, dividends paid by “qualified foreign corporations” to certain non-corporate U.S. owners of stock that is readily tradable on an “established securities market” in the United States may be taxed at a preferential rate. However, the preferential rate does not apply if we are (or are treated with respect to a U.S. Holder as) a PFIC for the taxable year in which the dividend is paid or the preceding taxable year. Non-corporate U.S. Holders should consult their tax advisors to determine whether the favorable rate will apply to dividends they receive

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(taking into account our PFIC status for any taxable year) and whether they are subject to any special rules that limit their ability to be taxed at this favorable rate in case it is otherwise available.

Dividends will be treated as foreign-source income for foreign tax credit purposes. As described in “— Material PRC Income Tax Considerations,” dividends paid by us may be subject to PRC withholding tax. For U.S. federal income tax purposes, the amount of the dividend income will include any amounts withheld in respect of PRC withholding tax. Subject to applicable limitations, which vary depending upon your circumstances, PRC taxes withheld from dividend payments (at a rate not exceeding any applicable rate provided by the Treaty) generally will be creditable against your U.S. federal income tax liability. The rules governing foreign tax credits are complex. For example, certain Treasury regulations (the “Foreign Tax Credit Regulations”) provide that, in the absence of an election to apply the benefits of an applicable income tax treaty, in order for non-U.S. income taxes to be creditable, the relevant non-U.S. income tax rules must be consistent with certain U.S. federal income tax principles, and we have not determined whether the PRC income tax system meets this requirement. The IRS has released notices that provide relief from certain of the provisions of the Treasury regulations described above for taxable years ending before the date that a notice or other guidance withdrawing or modifying the temporary relief is issued (or any later date specified of in such notice or other guidance). In lieu of claiming a credit, you may elect to deduct creditable PRC taxes in computing your taxable income, subject to applicable limitations. An election to deduct foreign taxes instead of claiming foreign tax credits applies to all otherwise creditable foreign taxes paid or accrued in the taxable year. You should consult your tax advisors regarding the creditability or deductibility of foreign taxes in your particular circumstances.

Sale or Other Disposition of ADSs or Ordinary Shares

The following is subject to the discussion under “— Passive Foreign Investment Company Rules” above.

The amount of the gain or loss recognized on a sale or other taxable exchange of ADSs or ordinary shares will equal the difference between your tax basis in the ADSs or ordinary shares disposed of and the amount realized on the disposition, in each case as determined in U.S. dollars. This gain or loss will generally be U.S.-source gain or loss for foreign tax credit purposes. The deductibility of capital losses is subject to limitations.

As described in “— Material PRC Income Tax Considerations” above, gains on the sale of ADSs or ordinary shares may be subject to PRC taxes. Under the Code, capital gains of U.S. persons are generally treated as U.S.-source income. However, you may be able to elect to treat the gain as foreign-source income under the Treaty and claim foreign tax credit in respect of any PRC tax on dispositions. The Foreign Tax Credit Regulations generally preclude you from claiming a foreign tax credit with respect to PRC income taxes on gains from dispositions of ADSs or ordinary shares if you do not elect to apply the benefits of the Treaty. The IRS has released notices that provide relief from certain of the provisions of the Foreign Tax Credit Regulations for taxable years ending before the date that a notice or other guidance withdrawing or modifying the temporary relief is issued (or any later date specified in such notice or other guidance). However, even if the Foreign Tax Credit Regulations do not prohibit you from claiming a foreign tax credit with respect to PRC taxes on disposition gains, other limitations under the foreign tax credit rules may preclude you from claiming (or limit your ability to claim) a foreign tax credit. In lieu of claiming a credit, it is possible that any PRC taxes on disposition gains may either be deductible or reduce the amount realized on the disposition. The rules governing foreign tax credits and deductibility of foreign taxes are complex. You should consult your tax advisor regarding the consequences of the imposition of any PRC tax on disposition gains, including the Treaty’s resourcing rule, any reporting requirements with respect to a Treaty-based return position and the creditability or deductibility of the PRC tax on disposition gains in your particular circumstances (including any applicable limitations).

Information Reporting and Backup Withholding

Payments of dividends and sales proceeds from the sale or exchange of our ADSs or ordinary shares that are made within the United States or through certain U.S.-related financial intermediaries generally are subject to information reporting, and may be subject to backup withholding, unless (i) you are a corporation or other exempt recipient (and if required, establish your exempt status) or (ii) in the case of backup

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withholding, you provide a correct taxpayer identification number and certify that you are not subject to backup withholding. Backup withholding is not an additional tax. The amount of any backup withholding from a payment to you will be allowed as a credit against your U.S. federal income tax liability and may entitle you to a refund, provided that the required information is timely furnished to the IRS.

Certain U.S. Holders who are individuals (and certain specified entities) may be required to report information relating to their ownership of ordinary shares, or non-U.S. accounts through which ADSs or ordinary shares are held. You should consult your tax advisor regarding your reporting obligations with respect to the ADSs and ordinary shares.

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UNDERWRITING

Leerink Partners LLC and LifeSci Capital LLC are acting as representatives of each of the underwriters named below and as joint bookrunning managers for this offering. Subject to the terms and conditions set forth in the underwriting agreement among us and the underwriters, we have agreed to sell to the underwriters, and each of the underwriters has agreed, severally and not jointly, to purchase from us, the number of the ADSs set forth opposite its name below.

Underwriter	Number of ADSs
Leerink Partners LLC		13,066,200
LifeSci Capital LLC		4,666,500
Lucid Capital Markets, LLC		933,300
Total		18,666,000

Subject to the terms and conditions set forth in the underwriting agreement, the underwriters have agreed, severally and not jointly, to purchase all of the ADSs sold under the underwriting agreement if any of the ADSs are purchased. If an underwriter defaults, the underwriting agreement provides that the purchase commitments of the non-defaulting underwriters may be increased or the underwriting agreement may be terminated.

We have agreed to indemnify the underwriters against certain liabilities, including liabilities under the Securities Act, or to contribute to payments the underwriters may be required to make in respect of those liabilities.

The underwriters are offering the ADSs, subject to prior sale, when, as and if issued to and accepted by them, subject to approval of legal matters by their counsel, including the validity of the ADSs, and subject to other conditions contained in the underwriting agreement, such as the receipt by the underwriters of officers’ certificates and legal opinions. The underwriters reserve the right to withdraw, cancel or modify offers to the public and to reject orders in whole or in part.

Discounts and Commissions

The representatives have advised us that the underwriters propose to offer the ADSs at the public offering price set forth on the cover page of this prospectus supplement and to dealers at that price less a concession not in excess of $0.135 per ADS. After the initial offering of the ADSs, the public offering price, concession or any other term of this offering may be changed by the representatives.

The following table shows the initial public offering price, underwriting discounts and commissions and proceeds, before expenses, to us.

	Per ADS	Total
Initial public offering price	$3.75	$69,997,500
Underwriting discounts and commissions	$0.225	$4,199,850
Proceeds, before expenses, to us	$3.525	$65,797,650

We estimate expenses payable by us in connection with this offering, other than the underwriting discounts and commissions referred to above, will be approximately $500,000. We also have agreed to reimburse the underwriters for up to $25,000 for their FINRA counsel fee. In accordance with FINRA Rule 5110, this reimbursed fee is deemed underwriting compensation for this offering.

No Sales of Similar Securities

We and our executive officers and directors have agreed not to sell or transfer any ADSs, Ordinary Shares or securities convertible into or exchangeable or exercisable for ADSs or Ordinary Shares, for 60 days after the date of this prospectus supplement without first obtaining the written consent of Leerink

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Partners LLC on behalf of the underwriters. Specifically, we and these other persons have agreed, with certain limited exceptions, not to directly or indirectly:

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offer, pledge, sell or contract to sell any ADSs or Ordinary Shares;

•

sell any option or contract to purchase any ADSs or Ordinary Shares;

•

purchase any option or contract to sell any ADSs or Ordinary Shares;

•

grant any option, right or warrant for the sale of any ADSs or Ordinary Shares;

•

otherwise dispose of or transfer any ADSs or Ordinary Shares;

•

request or demand that we file a registration statement related to the ADSs or Ordinary Shares; or

•

enter into any swap or other agreement or any transaction that transfers, in whole or in part, the economic consequence of ownership of any ADSs or Ordinary Shares, whether any such swap, agreement or transaction is to be settled by delivery of shares or other securities, in cash or otherwise.

The lock-up provisions apply to ADSs and Ordinary Shares and to securities convertible into or exchangeable or exercisable for ADSs or Ordinary Shares. They also apply to ADSs or Ordinary Shares owned now or acquired later by the person executing the lock-up agreement or for which the person executing the lock-up agreement later acquires the power of disposition.

Nasdaq Global Market Listing

Our ADSs are listed on the Nasdaq Global Market under the symbol “ADAG.”

Price Stabilization, Short Positions and Penalty Bids

Until the distribution of the ADSs is completed, SEC rules may limit underwriters and selling group members from bidding for and purchasing our ADSs. However, the representatives may engage in transactions that stabilize the price of the ADSs, such as bids or purchases to peg, fix or maintain that price.

In connection with this offering, the underwriters may purchase and sell our ADSs in the open market. These transactions may include short sales, purchases on the open market to cover positions created by short sales and stabilizing transactions. Short sales involve the sale by the underwriters of a greater number of ADSs than they are required to purchase in this offering. The underwriters must close out any naked short position by purchasing ADSs in the open market. A naked short position is more likely to be created if the underwriters are concerned that there may be downward pressure on the price of our ADSs in the open market after pricing that could adversely affect investors who purchase in this offering. Stabilizing transactions consist of various bids for or purchases of ADSs made by the underwriters in the open market prior to the closing of this offering.

The underwriters may also impose a penalty bid. This occurs when a particular underwriter repays to the underwriters a portion of the underwriting discount received by it because the representatives have repurchased ADSs sold by or for the account of such underwriter in stabilizing or short covering transactions.

Similar to other purchase transactions, the underwriters’ purchases to cover the syndicate short sales may have the effect of raising or maintaining the market price of our ADSs or preventing or retarding a decline in the market price of our ADSs. As a result, the price of our ADSs may be higher than the price that might otherwise exist in the open market. The underwriters may conduct these transactions on the Nasdaq Global Market, in the over-the-counter market or otherwise.

Neither we nor any of the underwriters make any representation or prediction as to the direction or magnitude of any effect that the transactions described above may have on the price of our ADSs. In addition, neither we nor any of the underwriters make any representation that the representatives will engage in these transactions or that these transactions, once commenced, will not be discontinued without notice.

Electronic Distribution

In connection with this offering, certain of the underwriters or securities dealers may distribute prospectuses by electronic means, such as e-mail.

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Other Relationships

The underwriters and certain of their affiliates are full service financial institutions engaged in various activities, which may include securities trading, commercial and investment banking, financial advisory, investment management, investment research, principal investment, hedging, financing and brokerage activities. Some of the underwriters and certain of their affiliates may in the future engage in investment banking and other commercial dealings in the ordinary course of business with us and our affiliates, for which they may in the future receive customary fees, commissions and expenses.

In addition, in the ordinary course of their business activities, the underwriters and their affiliates may make or hold a broad array of investments and actively trade debt and equity securities (or related derivative securities) and financial instruments (including bank loans) for their own account and for the accounts of their customers. Such investments and securities activities may involve securities and/or instruments of ours or our affiliates. The underwriters and their affiliates may also make investment recommendations and/or publish or express independent research views in respect of such securities or financial instruments and may hold, or recommend to clients that they acquire, long and/or short positions in such securities and instruments.

Selling Restrictions

Notice to Prospective Investors in the European Economic Area

In relation to each Member State of the European Economic Area (each, a “Relevant State”), no securities have been offered or will be offered pursuant to the offering to the public in that Relevant State prior to the publication of a prospectus in relation to the securities which has been approved by the competent authority in that Relevant State or, where appropriate, approved in another Relevant State and notified to the competent authority in that Relevant State, all in accordance with the Prospectus Regulation, except that securities may be offered to the public in that Relevant State at any time:

to any legal entity which is a qualified investor as defined under Article 2 of the Prospectus Regulation;

to fewer than 150 natural or legal persons (other than qualified investors as defined under Article 2 of the Prospectus Regulation), subject to obtaining the prior consent of the representatives for any such offer; or

in any other circumstances falling within Article 1(4) of the Prospectus Regulation,

provided that no such offer of securities shall require us or any of the representatives to publish a prospectus pursuant to Article 3 of the Prospectus Regulation or supplement a prospectus pursuant to Article 23 of the Prospectus Regulation or publish an Annex IX document pursuant to Article 1(4) of the Prospectus Regulation.

For the purposes of this provision, the expression an “offer to the public” in relation to any securities in any Relevant State means the communication in any form and by any means of sufficient information on the terms of the offer and any securities to be offered so as to enable an investor to decide to purchase or subscribe for any securities, and the expression “Prospectus Regulation” means Regulation (EU) 2017/1129.

Notice to Prospective Investors in the United Kingdom

No securities have been offered or will be offered pursuant to the offering to the public in the United Kingdom except that the securities may be offered to the public in the United Kingdom at any time:

(a)

where the offer is conditional on the admission of the securities to trading on the London Stock Exchange plc’s main market (in reliance on the exception in paragraph 6(a) of Schedule 1 of the POATR);

(b)

to any qualified investor as defined under paragraph 15 of Schedule 1 of the POATR;

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(c)

to fewer than 150 persons (other than qualified investors as defined under paragraph 15 of Schedule 1 of the POATR), subject to obtaining the prior consent of representatives for any such offer; or

(d)

in any other circumstances falling within Part 1 of Schedule 1 of the POATR.

For the purposes of this provision, the expression an “offer to the public” in relation to the securities in the United Kingdom means the communication to any person which presents sufficient information on: (a) the securities to be offered; and (b) the terms on which they are to be offered, to enable an investor to decide to buy or subscribe for the securities and the expressions “POATR” means the Public Offers and Admissions to Trading Regulations 2024.

Notice to Prospective Investors in Canada

The securities may be sold only to purchasers purchasing, or deemed to be purchasing, as principal that are accredited investors, as defined in National Instrument 45-106 Prospectus Exemptions or subsection 73.3(1) of the Securities Act (Ontario), and are permitted clients, as defined in National Instrument 31-103 Registration Requirements, Exemptions and Ongoing Registrant Obligations. Any resale of the securities must be made in accordance with an exemption from, or in a transaction not subject to, the prospectus requirements of applicable securities laws.

Securities legislation in certain provinces or territories of Canada may provide a purchaser with remedies for rescission or damages if this prospectus supplement (including any amendment thereto) contains a misrepresentation, provided that the remedies for rescission or damages are exercised by the purchaser within the time limit prescribed by the securities legislation of the purchaser’s province or territory. The purchaser should refer to any applicable provisions of the securities legislation of the purchaser’s province or territory for particulars of these rights or consult with a legal advisor.

Pursuant to section 3A.3 of National Instrument 33-105 Underwriting Conflicts (NI 33-105), the underwriters are not required to comply with the disclosure requirements of NI 33-105 regarding underwriter conflicts of interest in connection with this offering.

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LEGAL MATTERS

We are being represented by Davis Polk & Wardwell LLP with respect to certain legal matters of U.S. federal securities and New York state law. Certain legal matters with respect to U.S. federal and New York State law in connection with this offering will be passed upon for the underwriters by Latham & Watkins LLP. The validity of the Ordinary Shares represented by the ADSs offered in this offering and other certain legal matters as to Cayman Islands law will be passed upon for us by Walkers (Hong Kong). Legal matters as to PRC law will be passed upon for us by Jingtian & Gongcheng and for the underwriters by Zhong Lun Law Firm. Davis Polk & Wardwell LLP may rely upon Walkers (Hong Kong) with respect to matters governed by Cayman Islands law and Jingtian & Gongcheng with respect to matters governed by PRC law. Latham & Watkins LLP may rely upon Zhong Lun Law Firm with respect to matters governed by PRC law.

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EXPERTS

The financial statements incorporated in this prospectus supplement by reference to the Annual Report on Form 20-F for the year ended December 31, 2025 have been so incorporated in reliance on the report of PricewaterhouseCoopers Zhong Tian LLP, an independent registered public accounting firm, given on the authority of said firm as experts in auditing and accounting.

The office of PricewaterhouseCoopers Zhong Tian LLP is located at 42/F New Bund Center, 588 Dongyu Road, Pudong New Area, Shanghai 200126, the People’s Republic of China.

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WHERE YOU CAN FIND MORE INFORMATION

We have filed with the U.S. Securities and Exchange Commission a registration statement (including amendments and exhibits to the registration statement) on Form F-3 under the Securities Act. Our SEC filings are available to the public over the Internet at the SEC’s website at http://www.sec.gov. Copies of certain information filed by us with the SEC are also available on our website at www.adagene.com. Our website is not a part of this prospectus supplement and is not incorporated by reference in this prospectus supplement. We furnish reports and other information to the SEC. You may also read and copy any document we file at the SEC’s public reference facilities and the website of the SEC referred to above. Our file number with the SEC is 001-39997.

This prospectus supplement is part of a registration statement we filed with the SEC. This prospectus supplement omits some information contained in the registration statement in accordance with SEC rules and regulations. You should review the information and exhibits in the registration statement for further information on us and our consolidated subsidiaries and the securities we are offering. Statements in this prospectus supplement concerning any document we filed as an exhibit to the registration statement or that we otherwise filed with the SEC are not intended to be comprehensive and are qualified by reference to these filings. You should review the complete document to evaluate these statements.

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INCORPORATION BY REFERENCE

The SEC allows us to incorporate by reference information into this document. This means that we can disclose important information to you by referring you to another document filed separately with the SEC. The information incorporated by reference is considered to be a part of this document, except for any information superseded by information that is included directly in this prospectus supplement incorporated by reference subsequent to the date of this prospectus supplement.

We incorporate by reference the following documents or information that we have filed with the SEC:

•

our annual report on Form 20-F for the fiscal year ended December 31, 2025, filed with the SEC on April 1, 2026; and

•

the description of our Ordinary Shares contained in the registration statement on Form 8-A filed with the SEC on February 3, 2021, and any other amendment or report filed for the purpose of updating such description.

All reports and other documents we subsequently file pursuant to Section 13(a), 13(c) or 15(d) of the Exchange Act prior to the termination of this offering, including, but excluding any information furnished to, rather than filed with, the SEC, will also be incorporated by reference into this prospectus supplement and the accompanying prospectus and deemed to be part of this prospectus supplement and the accompanying prospectus from the date of the filing of such reports and documents.

Potential investors, including any beneficial owner, may obtain a copy of any of the documents summarized herein (subject to certain restrictions because of the confidential nature of the subject matter) or any of our SEC filings incorporated by reference herein without charge by written request directed to 4F, Building C14, No. 218, Xinghu Street, Suzhou Industrial Park Suzhou, Jiangsu Province, 215123, People’s Republic of China.

You should rely only on the information incorporated by reference or provided herein. We have not authorized anyone else to provide you with different information. We are not making an offer of these securities in any state where the offer is not permitted. You should not assume that the information in this prospectus supplement is accurate as of any date other than the date on the front of those documents.

Any statement contained in a document incorporated by reference herein shall be deemed to be modified or superseded for purposes of this prospectus supplement to the extent that a statement contained herein, or in a subsequently filed document incorporated by reference herein, modifies or supersedes that statement. Any statement so modified or superseded shall not be deemed, except as so modified or superseded, to constitute part of this prospectus supplement.

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PROSPECTUS

US$200,000,000

Adagene Inc.

Ordinary Shares
Warrants
Units

Adagene Inc. (“Adagene” or “the Company”) may offer from time to time up to a total amount of US$200,000,000, consisting of (i) ordinary shares of the Company, par value US$0.0001 per share (“Ordinary Shares”), including ordinary shares represented by American depositary shares, or ADSs, (ii) warrants to purchase ordinary shares or other securities of the Company (“Warrants”), (iii) units (“Units” and, collectively with the Ordinary Shares and Warrants, the “Securities”), or any combination thereof, in one or more offerings under this prospectus. Each ADS represents one and one quarter (1.25) ordinary shares. When we decide to sell Securities, we will provide specific terms of the offered Securities in a prospectus supplement.

This prospectus describes some of the general terms that may apply to these Securities and the general manner in which they may be offered. The specific terms of any Securities to be offered, and the specific manner in which they may be offered, will be described in one or more supplements to this prospectus. A prospectus supplement may also add, update or change information contained in this prospectus.

The Securities covered by this prospectus may be offered and sold from time to time in the same offering or in separate offerings; to or through underwriters, dealers, and agents; or directly to purchasers. The names of any underwriters, dealers, or agents, if any, involved in the sale of our Securities, their compensation and any over-allotment options held by them will be described in the applicable prospectus supplement. For a more complete description of the plan of distribution of these Securities, see the section entitled “Plan of Distribution” beginning on page 74 of this prospectus.

The ADSs are traded on the Nasdaq Global Market, or the Nasdaq, under the symbol “ADAG.” As of May 29, 2025, the last reported sale price for the ADSs was US$1.955 per ADS. Pursuant to General Instruction I.B.5 of Form F-3, in no event will we sell the Securities covered hereby in a public primary offering with a value exceeding more than one-third of the aggregate market value of our voting and non-voting common equity held by non-affiliates in any 12-month period so long as the aggregate market value of our outstanding voting and non-voting common equity held by non-affiliates remains below US$75,000,000. During the 12 calendar months prior to and including the date of this prospectus, we have not offered or sold any securities pursuant to General Instruction I.B.5 of Form F-3.

Investors in the ADSs are purchasing securities of a Cayman Islands holding company rather than securities of our subsidiaries that have substantive business operations in the United States or China. Adagene Inc. is a Cayman Islands holding company that conducts its operations and operate 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 Adagene Suzhou. Such structure involves unique legal and operational risks to investors in the ADSs and Ordinary Shares. In particular, the PRC government has significant authority to exert influence on the ability of a company with substantive operations in China, such as us, to conduct its business, accept foreign investments or list on a U.S. or other foreign exchanges. For example, we face risks associated with regulatory approvals of offshore offerings, anti-monopoly regulatory actions, oversight on cybersecurity and data privacy. Such risks could result in a material change in our operations and/or the value of the ADSs representing our Ordinary Shares or could significantly limit or completely hinder our ability to offer or continue to offer our Ordinary Shares represented by ADSs to investors and cause the value of such securities to significantly decline or become worthless. As we are a holding company with substantive business operations in China, you should pay special attention to disclosures included in our most recent annual report on Form 20-F incorporated by reference in this prospectus and risk factors included herein.

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China and Hong Kong is subject to uncertainty and depends on a number of factors out of our, and our auditor’s, control, including positions taken by authorities of the PRC. The PCAOB is expected to continue to demand complete access to inspections and investigations against accounting firms headquartered in mainland China and Hong Kong in the future. The PCAOB is required under the HFCAA to make its determination on an annual basis with regards to its ability to inspect and investigate completely accounting firms based in the mainland China and Hong Kong. The possibility of being a “Commission-Identified Issuer” and risk of delisting could continue to adversely affect the trading price of our securities. If the PCAOB determines in the future that it no longer has full access to inspect and investigate accounting firms headquartered in mainland China and Hong Kong and we continue to use such accounting firm to conduct audit work, we would be identified as a “Commission-Identified Issuer” under the HFCAA following the filing of the annual report for the relevant fiscal year, and if we were so identified for two consecutive years, trading in our securities on U.S. markets would be prohibited under the HFCAA.

As used in this prospectus supplement, “Adagene” refers to Adagene Inc., a Cayman Islands exempted company with limited liability, “Adagene Incorporated” refers to Adagene Incorporated, our U.S. subsidiary, “Adagene Suzhou” refers to Adagene (Suzhou) Limited, a PRC incorporated company with limited liability, “Adagene Hong Kong” refers to Adagene (Hong Kong) Limited, our Hong Kong intermediary holding company, , and “we,” “us,” “our company,” or “our” refers to Adagene Inc. and its subsidiaries.

With a holding company structure, we currently rely principally on equity financing for our cash requirements, including the funds necessary to pay cash considerations for services we may incur. In the future, if we become profitable and generate cash flows from operating activities, we may rely principally on dividends and other distributions on equity from our U.S., PRC and other subsidiaries for our cash requirements, including the funds necessary to pay dividends and other cash distributions to our shareholders or for services of any debt we may incur. If any of our subsidiaries or any newly formed subsidiaries incur debt on their own behalf in the future, the instruments governing their debt may restrict their ability to pay dividends or make other distributions to us. In 2022, 2023 and 2024, Adagene Inc. made payments of US$24.5 million, US$20.5 million and US$16.3 million, respectively, in cash to Adagene Suzhou as consideration for providing services associated with research and development activities related to those intellectual properties owned by Adagene Inc. There were no intercompany loans provided by Adagene Inc. to Adagene Suzhou during the years ended and as of December 31, 2022, 2023 and 2024. As advised by our PRC legal counsel, Jingtian & Gongcheng, Adagene Suzhou is able to mark up and charge to Adagene Inc., its ultimate parent, for providing services associated with research and development activities related to those intellectual properties owned by Adagene Inc. and Adagene Inc. is able to make cash payments to Adagene Suzhou for considerations of such services. In the future, cash proceeds raised from overseas financing activities, including this offering, may be transferred by Adagene Inc., the Cayman Islands holding company, (i) to Adagene Incorporated, our U.S. subsidiary, (ii) through Adagene (Hong Kong) Limited, our Hong Kong subsidiary, to Adagene Suzhou, our PRC subsidiary and (iii) to other subsidiaries, via capital contribution, shareholder loans or consideration for the services rendered, as the case may be. Other than the above disclosed transfer of funds, we did not transfer any type of assets between Adagene Suzhou and other Adagene subsidiaries in 2022, 2023 or 2024. For risks associated with this structure, see “Item 3. Key Information — 3.D. Risk Factors — Risks Related to Doing Business in China — We may rely on dividends and other distributions on equity paid by our PRC subsidiary to fund any cash and financing requirements that we may have, and any limitation on the ability of our PRC subsidiary to make payments to us could have material and adverse effect on our ability to conduct our business” and “— PRC regulation of loans to and direct investment in PRC entities by offshore holding companies and governmental control of currency conversion may delay or prevent us from using the proceeds of our public offering to make loans or additional capital contributions to our PRC subsidiary, which could materially and adversely affect our liquidity and our ability to fund and expand our business” in our most recent annual report on Form 20-F incorporated by reference in this prospectus.

Investing in these Securities involves certain risks. Please carefully consider the “Risk Factors” in Item 3.D of our most recent annual report on Form 20-F incorporated by reference in this prospectus, the “Risk Factors” beginning on page 14 of this prospectus, and in any applicable prospectus supplement, for a discussion of the factors you should consider carefully before deciding to purchase these Securities.

This prospectus may not be used to offer or sell any Securities unless accompanied by a prospectus supplement.

Neither the Securities and Exchange Commission nor any state or other securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The date of this prospectus is May 30, 2025.

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PROSPECTUS

	Page
About This Prospectus		1
Our Company		3
Risk Factors		14
Cautionary Note Regarding Forward-Looking Statements		33
Use of Proceeds		35
Capitalization and Indebtedness		36
Description of Share Capital and Memorandum and Articles of Association		37
Description of Warrants		46
Description of Units		47
Forms of Securities		48
Description of American Depositary Shares		50
Enforceability of Civil Liabilities		65
Taxation		67
Plan of Distribution		68
Expenses		72
Incorporation of Certain Documents by Reference		73
Legal Matters		74
Experts		75
Where You Can Find More Information		76

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ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement that we filed with the U.S. Securities and Exchange Commission, or the SEC, using a “shelf” registration process. Under this shelf registration process, we may, from time to time, sell up to US$200,000,000 of any combination of the Securities described in this prospectus. This prospectus provides you with a general description of the Securities we may offer. Each time we use this prospectus to offer Securities, we will provide one or more prospectus supplements that will contain specific information about the offering and the terms of those Securities. We may also add, update or change other information contained in this prospectus by means of a prospectus supplement or by incorporating by reference information we file with the SEC. The registration statement on file with the SEC includes exhibits that provide more detail on the matters discussed in this prospectus. If there is any inconsistency between the information in this prospectus and any related prospectus supplement, you should rely on the information in the applicable prospectus supplement.

Before buying any of the Securities that we are offering, you should carefully read both this prospectus and any prospectus supplement with all of the information incorporated by reference in this prospectus, as well as the additional information described under the heading “Where You Can Find More Information” and “Incorporation of Certain Documents by Reference.” These documents contain important information that you should consider when making your investment decision. We have filed or incorporated by reference exhibits to the registration statement of which this prospectus forms a part. You should read the exhibits carefully for provisions that may be important to you.

The information contained in this prospectus, any applicable prospectus supplement or any document incorporated by reference in this prospectus is accurate only as of their respective dates, regardless of the time of delivery of this prospectus, any applicable prospectus supplement or the documents incorporated by reference in this prospectus or the sale of any Securities. Our business, financial condition, results of operations and prospects may have changed materially since those dates.

Neither we nor any underwriters, dealers or agents have authorized anyone to provide you with information that is different from that contained in this prospectus, any amendment or supplement to this prospectus, or any free writing prospectus we may authorize to be delivered or made available to you. Neither we nor any underwriters, dealers or agents take responsibility for, or provide assurance as to the reliability of, any other information that others may give you. This prospectus does not constitute an offer to sell or the solicitation of an offer to buy any securities other than the Securities described in this prospectus or an offer to sell or the solicitation of an offer to buy such Securities in any circumstances in which such offer or solicitation is unlawful.

Neither we nor any underwriters, dealers or agents have taken any action that would permit the offering or possession or distribution of this prospectus in any jurisdiction where action for that purpose is required, other than in the United States. Persons outside the United States who come into possession of this prospectus must inform themselves about, and observe any restrictions relating to, the offering of the Securities described herein and the distribution of this prospectus outside the United States.

In this prospectus, unless otherwise indicated or unless the context otherwise requires,

•

“Adagene Suzhou” refers to Adagene (Suzhou) Limited, our subsidiary in the PRC;

•

“Adagene Incorporated” refers to Adagene Incorporated, our subsidiary in the U.S.;

•

“ADSs” refers to the American depositary shares, each representing one and one quarter (1.25) of our ordinary shares;

•

“Antibody binding interface” or “antibody binding sites” refers to the antibody binding surface spots in contact with its recognition antigen;

•

“China” or “PRC” refers to the People’s Republic of China;

•

“conformational diversity” or “dynamic diversity” refers to the existence of more than one conformation or structure due to dynamic fluctuation of the structures for a given protein sequence, independent of any conformational changes caused by external binding;

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•

“epitopes” or “epitope of an antigen” refers to the specific binding spots of an antigen in contact with its antibody binding surface;

•

“Exchange Act” refers to the Exchange Act of 1934, as amended;

•

“Greater China”, for the purpose of this prospectus/registration statement, refers to the People’s Republic of China, Hong Kong, Macau and Taiwan;

•

“multi-specificity” refers to a protein exerting a similar function (such as binding) on distinctly different ligands, perhaps while using different active site residues;

•

“NEObody(ies)” refers to antibody(ies) designed with dynamic binding sites that adapt kinetically to unique epitopes through novel MOA(s), using our NEObody technology; NEObody® is a registered trademark in the United States, China, Australia, Japan, Singapore, Switzerland, Korea, United Kingdom and the European Union;

•

“ordinary shares” or “shares” refers to our ordinary shares of par value US$0.0001 per share;

•

“POWERbody(ies)” refers to antibody(ies) that utilize(s) our SAFEbody technology to create new bispecific T-cell engagers, antibody-drug conjugates, or antibody(ies), which is(are) designed to reach beyond the therapeutic potency of traditional monospecific antibody(ies); POWERbody® is a registered trademark in the United States, China, Australia, Japan, Singapore, Switzerland, Korea, United Kingdom and the European Union;

•

“RMB” or “Renminbi” refers to the legal currency of the People’s Republic of China;

•

“SAFEbody(ies)” refers to antibody(ies) engineered with its(their) binding sites masked, which is(are) designed to be selectively activated in the tumor microenvironment (TME), potentially limiting on-target off-tumor toxicity in normal tissues; SAFEbody® is a registered trademark in the United States, China, Australia, Japan, Singapore, and the European Union; SAFEbody® is a registered trademark in the United States, China, Australia, Japan, Singapore, Switzerland, Korea, United Kingdom and the European Union;

•

“Securities Act” refers to the Securities Act of 1933, as amended;

SEC Form 424B5 filed by Adagene Inc.