[Amended] Material event report (merger)

What happened

AMENDMENT (August 26, 2026) 1. Disclosure document subject to amendment: Material event report (merger decision) 2. Original submission date of the disclosure document subject to amendment: May 18, 2026 3. Amended item Item: 18. Other important matters relevant to investment decisions Reason for amendment: Withdrawal of all related matters following withdrawal of the merger decision Before amendment: "For further details on this merger, please refer to the Company's securities registration statement to be disclosed later." After amendment: "This amendment to the material event report reflects a schedule change; however, as of the amendment date of this material event report (2026.08.04), the revised schedule has not been determined (as stated in the filing). Once a revised schedule is confirmed, it will be re-disclosed through a board resolution and a further amendment to this material event report." ※ Regarding withdrawal of the merger decision The Company decided, by board resolution on May 18, 2026, to merge with Huons Lab Co., Ltd., and disclosed the related material event report. The merger was pursued mainly to secure a biologics/new-drug pipeline to drive future growth and create synergy through integration of R&D capabilities. After deciding on and disclosing the merger, in light of opposition raised by shareholders of parent company Huons Global Co., Ltd. and the intent of newly established duplicate-listing guidelines, the Company pre-emptively postponed the merger schedule to sufficiently communicate with and gather input from shareholders and prepare shareholder-protection measures. The Company also gathered input from various stakeholders, including minority shareholders, while continuing to review the merger's effect on existing shareholders' rights and value. Due to these regulatory changes and conflicts of interest between parent- and subsidiary-company shareholders, the merger schedule was delayed considerably compared to the original plan. In the meantime, Korea's stock market showed sharp volatility, and amid a broader decline in investment sentiment toward the pharmaceutical/bio sector and other changes the Company could not predict or control, the Company's share price declined, widening the gap between the merger value and appraisal-right exercise price calculated at the time of the merger decision and the current market price. As circumstances both internal and external have changed considerably compared to when the merger agreement was executed, the Company determined that proceeding with the merger as originally planned carries a high risk of impairing existing shareholder value; while the need for business synergy and medium- to long-term growth drivers through the merger remains valid, the Company decided to halt the merger, giving top priority to protecting existing shareholder value. Accordingly, the Company resolved, by board resolution on August 26, 2026, to terminate the merger agreement and withdraw the merger decision. All procedures related to the merger, including the extraordinary general shareholders' meeting, are therefore cancelled, and investors are asked to take note of this. The Company will continue its efforts to enhance corporate and shareholder value going forward.

Material event report / Exchange reporting obligation matter To the Financial Services Commission / Korea Exchange May 18, 2026 Company name: Huons Co., Ltd. CEO: Song Su-young Head office address: 8th floor, Huons Global Building, 17 Changbeop-ro, A-dong, Sujeong-gu, Seongnam-si, Gyeonggi-do Phone: 02-854-4700 Website: www.huons.com Preparer: Kim Jeong-hoon, Head of Corporate Disclosure, Phone 02-854-4700

Company merger decision

※ Regarding withdrawal of the merger decision [Same withdrawal explanation as set out above, restated verbatim within the original report.]

1. Merger method a. Huons Co., Ltd. will absorb Huons Lab Co., Ltd. - Surviving company (merging company): Huons Co., Ltd. (KOSDAQ-listed) - Dissolving company (company to be merged): Huons Lab Co., Ltd. (unlisted) b. The surviving company's trade name after the merger is Huons Co., Ltd. - Merger type: Not applicable

2. Purpose of merger To resolve the structural limitation of a shortage of new-drug pipelines to drive future growth and intensifying downward pressure on revenue and profitability from the government's drug-pricing system reform, and to leap forward as a global pharma/bio company by building a full biologics value chain and strengthening R&D capability.

3. Material effects of the merger 1) Effect on management: Through this merger, merging company Huons Co., Ltd. will absorb Huons Lab Co., Ltd., and the merging company will remain a listed corporation. Other than the change in ownership ratio from delivering 3,825,373 new merger shares (24.20%) to Huons Lab Co., Ltd.'s shareholders as of the record date, there is no change in control or governance such as the largest shareholder. 2) Effect on finances: As the merging company absorbs Huons Lab Co., Ltd., R&D expense will increase in the short term, but the Company plans to ultimately improve its financial structure and profitability by strengthening the clinical pipeline and maximizing management efficiency, including reduced duplicate investment costs and internalized outsourced costs from leveraging Huons Co., Ltd.'s clinical personnel, know-how and production facilities. 3) Effect on operations: The merger will integrate both companies' technology, expertise and experience to strengthen the new-drug development pipeline through synthetic and biologic new-drug R&D. Huons Lab Co., Ltd. has completed a domestic product license application for a finished drug product based on human-derived hyaluronidase, and once its drug-diffusion platform technology is commercialized, sales growth and cost reduction are expected from synergy leveraging Huons Co., Ltd.'s infrastructure and sales organization. 4) Effect on shareholder value: The management efficiency and synergy from this merger will increase shareholder value over the long term. After the merger, Huons Co., Ltd. will add Huons Lab Co., Ltd.'s new-drug/biosimilar pipeline to its existing generic-drug-centered business structure and secure excellent R&D personnel and original patents, strengthening the Company's competitiveness and corporate value.

4. Merger ratio Huons Co., Ltd. : Huons Lab Co., Ltd. = 1 : 0.4256943

5. Basis for calculating the merger ratio 1) Huons Co., Ltd. common-share merger value: For a listed corporation, the merger value in principle applies the market reference price, but under Article 176-5, Paragraph 1, Item 2(a) of the Capital Markets Act Enforcement Decree, if the market reference price is lower than the asset value, the asset value may be used instead. The market reference price of KOSDAQ-listed Huons Co., Ltd.'s common shares was calculated as of the day before (May 15, 2026) the earlier of the initial board resolution date (May 18, 2026) and the initial merger agreement date (May 18, 2026), as the arithmetic average of the volume-weighted arithmetic average closing price over the most recent 1 month, the volume-weighted arithmetic average closing price over the most recent 1 week, and the most recent closing price, with no premium or discount applied. a. Most recent 1-month weighted arithmetic average closing price (A): KRW 32,292 b. Most recent 1-week weighted arithmetic average closing price (B): KRW 35,095 c. Most recent closing price (C): KRW 34,800 d. Arithmetic average value (D=(A+B+C)/3): KRW 34,062 e. Merger value: KRW 34,062 2) Huons Lab Co., Ltd. common-share merger value: Under Article 176-5 of the Capital Markets Act Enforcement Decree, Article 5-13 of the Regulation on Issuance and Disclosure of Securities and Article 4 of its Enforcement Rules, the merger value of an unlisted company is calculated as the weighted arithmetic average of asset value and earnings value in a 1:1.5 ratio (the "intrinsic value"); relative value was analyzed for reference but not calculated, as fewer than 3 listed companies exist in the same detailed KRX industry sub-classification as the company to be merged. a. Intrinsic value [(Ax1+Bx1.5)/2.5]: KRW 14,500 - A. Asset value: KRW 808 - B. Earnings value: KRW 23,628 b. Relative value: Not applicable c. Merger value: KRW 14,500 For details, please refer to the external appraisal institution's opinion letter attached. As above, the merger ratio of Huons Co., Ltd.'s common shares to Huons Lab Co., Ltd.'s common shares was determined as 1:0.4256943. Note: company to be merged Huons Lab currently has 817,617 redeemable convertible preferred shares outstanding, all of which will be converted to common shares before the merger date; under the contractual refixing terms, the total number of common shares to be converted is 905,420. - Corporate value: surviving company 408,051,349,230; dissolving company 129,026,872,500

6. External appraisal Applicable. Basis and reason: Under Article 176-5, Paragraph 7, Item 2(a) of the Capital Markets Act Enforcement Decree, where a listed corporation merges with an unlisted corporation and the listed corporation's merger value is calculated under Paragraph 1, Item 2(b) of the same Enforcement Decree, an external appraisal institution's evaluation of the appropriateness of the merger value was obtained. Name of appraisal institution: Yichon Accounting Corporation Appraisal period: April 29, 2026 - May 15, 2026 Appraisal opinion: Yichon Accounting Corporation (the "Appraiser") reviewed the appropriateness of the merger ratio between KOSDAQ-listed Huons Co., Ltd. (the "merging company") and unlisted Huons Lab Co., Ltd. (the "company to be merged"). This opinion letter was prepared for use as an attachment to the merging companies' filing under the Capital Markets Act, and the Appraiser's evaluation may not be used for any other purpose or by any other party. The Appraiser reviewed the merging company's audited separate financial statements and share price data prepared under K-IFRS for the fiscal year ended December 31, 2025, the company to be merged's audited financial statements prepared under K-IFRS for the fiscal year ended December 31, 2025, a 16-year business plan from January 2026 to December 2041, and the business reports of comparable listed companies in the same detailed KRX industry sub-classification. The Appraiser complied with the Financial Supervisory Service's "External Appraisal Work Guidelines (June 2009)" and the Korean Institute of Certified Public Accountants' "Standards for Performing External Appraisal Work under the Capital Markets Act (November 2024)," and relevant ethical requirements. The Appraiser's evaluation found the per-share value underlying the merger ratio to be KRW 34,062 (par value KRW 500) for the merging company and in the range of KRW 12,671 to KRW 14,672 (par value KRW 500) for the company to be merged, implying a merger-ratio range of 1:0.3719819 to 1:0.4307447. As the agreed ratio of 1:0.4256943 falls within this range, the Appraiser judged it to be appropriate, finding no material departure from the merger-value calculation methods prescribed in Article 176-5 of the Capital Markets Act Enforcement Decree, Article 5-13 of the Regulation on Issuance and Disclosure of Securities, and Articles 4 through 8 of its Enforcement Rules.

7. Type and number of new merger shares (shares) Common shares: 3,825,373; preferred shares: -

8. Merger counterparty Company name: Huons Lab Co., Ltd. Main business: Biopharmaceutical R&D Relationship with the Company: Affiliate Most recent fiscal year financial details (KRW): Total assets: 8,261,890,851 Capital: 4,040,394,000 Total liabilities: 10,062,942,137 Revenue: 83,816,403 Total equity: -1,801,051,286 Net income: -10,189,367,413 External audit: Samil PwC, opinion unqualified; representative, date of incorporation, head office, expected securities registration filing date for SPAC-dissolution merger: not applicable, -

9. Newly incorporated merger company: all items -; relisting application: Not applicable

10. Merger schedule Merger contract date: May 18, 2026 Record date for determining shareholders: July 30, 2026 Shareholder register closure period: - Period for receiving notices of opposition to merger: - Expected general shareholders' meeting date: - Appraisal rights exercise period: - Old share certificate submission period: - Expected trading suspension period: - Creditor objection period: - Merger date: - Closing report general meeting date: - Expected merger registration date: - Expected date of delivery of new share certificates: - Expected listing date of new shares: -

11. Backdoor listing: Not applicable 12. Whether another company's backdoor listing requirements are met: Not applicable

13. Appraisal rights Exercise requirements: Under Article 522-3 of the Commercial Act and Article 165-5 of the Capital Markets Act, a shareholder of record as of the record date who notifies the Company in writing of opposition to the merger board resolution before the shareholders' meeting resolution date may, within 20 days of that resolution date, request in writing (stating type and number of shares) that the Company purchase some or all of the shares owned. However, under Article 165-5, Paragraph 1 of the Capital Markets Act and Article 176-7, Paragraph 2 of its Enforcement Decree, appraisal rights are granted only for shares shown to have been acquired before the merging companies' board resolution was disclosed, or shown by the following business day to be subject to (i) a purchase contract, (ii) termination of a securities lending agreement, or (iii) another legal act of acquisition, and continuously held through the date of exercising appraisal rights; shares sold and reacquired within that period lose appraisal rights, and once exercised, appraisal rights cannot be withdrawn. A shareholder who gave prior written notice of opposition but then votes in favor at the shareholders' meeting may not exercise appraisal rights. As Huons Co., Ltd. is KOSDAQ-listed, it must purchase the shares within one month of the end of the appraisal-rights exercise period under Article 165-5, Paragraph 2 of the Capital Markets Act. Expected purchase price: KRW 32,886 Exercise procedure, method, period, location: a. Method of expressing opposition: A shareholder of record as of the record date (July 30, 2026) meeting the acquisition-timing requirements above and continuously holding the shares through exercise must notify the Company in writing of opposition to the merger board resolution before the shareholders' meeting; a beneficial shareholder whose shares are held in custody by a securities company must notify that company. Opposition must be given by 3 business days before the shareholders' meeting (-); securities companies must report collected opposition notices to Korea Securities Depository by 2 business days before the meeting (-); Korea Securities Depository must notify the Company on beneficial shareholders' behalf by 1 business day before the meeting (-). Reception deadlines may differ by securities company. b. Method of requesting purchase: A shareholder who gave timely written notice of opposition may, within 20 days of the shareholders' meeting resolution date, request the Company in writing (stating type and number of shares) to purchase some or all of the shares owned; a beneficial shareholder may request purchase via the custodying securities company, which Korea Securities Depository will file on the shareholder's behalf if requested by 2 business days before the end of the exercise period (-). Once exercised, the request cannot be cancelled or withdrawn without the Company's consent. c. Reception location: (1) Huons Co., Ltd. (merging company) - registered shareholders: 8th floor, Huons Global Building, 17 Changbeop-ro, A-dong, Sujeong-gu, Seongnam-si, Gyeonggi-do; beneficial shareholders: the relevant securities company. (2) Huons Lab Co., Ltd. (company to be merged) - registered shareholders: 7th floor, Huons Global Building, same address; beneficial shareholders: the relevant securities company. d. Request period: period for receiving notices of opposition -; expected shareholders' meeting date -; appraisal-rights exercise period -. The purchase price and procedures may change as the process proceeds. Expected payment timing and method: a. Payment to registered shareholders will be transferred to the shareholder's registered bank account; payment to beneficial shareholders will be transferred to the shareholder's account at the custodying securities company. b. Expected payment timing: Huons Co., Ltd. -; Huons Lab Co., Ltd. -; may change due to the merging companies' circumstances. Restrictions on appraisal rights: As described above under exercise requirements; shares sold and reacquired within the period lose appraisal rights, exercised rights cannot be withdrawn, and a shareholder who later votes in favor at the shareholders' meeting may not exercise appraisal rights. Effect on the contract: After each merging company's shareholders' meeting approves the merger, if the aggregate purchase price for shares subject to appraisal-rights exercise exceeds, as of the expiration of the exercise period, KRW 30 billion for Huons Co., Ltd. or KRW 4 billion for Huons Lab Co., Ltd., the merging companies may by board resolution decide whether to proceed with the merger.

14. Board resolution date (decision date): May 18, 2026 - Independent (outside) directors present: 3, absent: 0 - Attendance of auditor (audit committee member who is not an independent (outside) director): -

15. Put option or similar contracts: No; contract details: -

16. Subject to securities registration statement: Yes; reason for exemption, if applicable: -

17. Future plans for corporate restructuring Nothing specifically determined regarding corporate restructuring currently being pursued or planned after completion of the merger; the Company will disclose per relevant disclosure regulations if any specific resolution is made in future.

18. Other important matters relevant to investment decisions a. Under Articles 522 and 434 of the Commercial Act, the shareholders' meeting resolution approving the merger is a special resolution matter; this merger may fail if the extraordinary general shareholders' meeting does not obtain approval of at least two-thirds of the voting rights of shareholders present and at least one-third of the total issued shares. b. Other than cash paid for handling odd-lot shares arising from the allotment of new shares, no consideration will be paid to shareholders of the companies participating in this merger. c. The "7. Type and number of new merger shares" above may change depending on the results of Huons Lab Co., Ltd. shareholders' exercise of appraisal rights and the handling of odd-lot shares. d. The "8. Merger counterparty" Huons Lab Co., Ltd.'s financial details above are based on financial statements as of the end of 2025. e. The matters and schedule in "10." may change through consultation with or approval of relevant authorities and between the contracting parties. f. The closing report meeting in "10. Merger schedule" above will be replaced by board resolution and announcement under Article 526, Paragraph 3 of the Commercial Act. g. Details regarding "13. Appraisal rights - expected purchase price": under Article 165-5, Paragraph 3 of the Capital Markets Act, the share purchase price is determined by agreement between the shareholder and the Company; if agreement is not reached, the price is calculated under Article 176-7, Paragraph 3 of the Capital Markets Act Enforcement Decree based on market trading prices before the board resolution date, and a disagreeing shareholder may petition the court to determine the price. [Huons Co., Ltd. expected purchase-price calculation method] (Capital Markets Act Enforcement Decree Article 176-7, Paragraph 3) Price proposed by the Company for negotiation: KRW 32,886 Basis: the amount calculated under the purchase-price method of Capital Markets Act Article 165-5 and its Enforcement Decree Article 176-7 Method if agreement is not reached: the amount calculated based on securities-market trading prices under Capital Markets Act Article 165-5 and Enforcement Decree Article 176-7; a disagreeing shareholder may petition the court to determine the purchase price. (1) Method of calculating the expected share purchase price (reference date: May 15, 2026) (1) Most recent 2-month volume-weighted average price: KRW 31,271 (period March 16, 2026 - May 15, 2026) (2) Most recent 1-month volume-weighted average price: KRW 32,292 (period April 16, 2026 - May 15, 2026) (3) Most recent 1-week volume-weighted average price: KRW 35,095 (period May 11, 2026 - May 15, 2026) Reference purchase price [(1)+(2)+(3)/3]: KRW 32,886 (2) Calculation detail (KRW, shares) -- date: closing price; volume; closing price x volume: 2026/05/15: 34,800; 108,454; 3,774,199,200 2026/05/14: 34,850; 91,761; 3,197,870,850 2026/05/13: 36,050; 265,024; 9,554,115,200 2026/05/12: 35,250; 336,137; 11,848,829,250 2026/05/11: 34,250; 296,555; 10,157,008,750 2026/05/08: 30,250; 130,449; 3,946,082,250 2026/05/07: 28,850; 144,021; 4,155,005,850 2026/05/06: 27,450; 56,853; 1,560,614,850 2026/05/04: 26,450; 72,635; 1,921,195,750 2026/04/30: 26,400; 20,942; 552,868,800 2026/04/29: 26,700; 25,527; 681,570,900 2026/04/28: 26,700; 23,555; 628,918,500 2026/04/27: 26,800; 38,759; 1,038,741,200 2026/04/24: 26,850; 31,638; 849,480,300 2026/04/23: 26,600; 36,231; 963,744,600 2026/04/22: 26,700; 7,617; 203,373,900 2026/04/21: 26,500; 30,353; 804,354,500 2026/04/20: 27,000; 14,131; 381,537,000 2026/04/17: 27,350; 48,362; 1,322,700,700 2026/04/16: 27,300; 18,928; 516,734,400 2026/04/15: 26,800; 20,675; 554,090,000 2026/04/14: 26,300; 12,980; 341,374,000 2026/04/13: 26,050; 18,916; 492,761,800 2026/04/10: 25,850; 16,933; 437,718,050 2026/04/09: 25,350; 8,384; 212,534,400 2026/04/08: 25,250; 16,337; 412,509,250 2026/04/07: 24,750; 18,104; 448,074,000 2026/04/06: 25,000; 9,150; 228,750,000 2026/04/03: 25,300; 6,372; 161,211,600 2026/04/02: 25,450; 29,837; 759,351,650 2026/04/01: 26,300; 9,542; 250,954,600 2026/03/31: 25,350; 15,431; 391,175,850 2026/03/30: 25,750; 13,136; 338,252,000 2026/03/27: 26,250; 12,448; 326,760,000 2026/03/26: 26,250; 19,371; 508,488,750 2026/03/25: 26,400; 20,487; 540,856,800 2026/03/24: 25,950; 14,833; 384,916,350 2026/03/23: 25,450; 15,526; 395,136,700 2026/03/20: 26,300; 15,507; 407,834,100 2026/03/19: 25,900; 13,057; 338,176,300 2026/03/18: 26,350; 11,119; 292,985,650 2026/03/17: 26,300; 10,254; 269,680,200 2026/03/16: 26,150; 11,541; 301,797,150 (1) Most recent 2-month volume-weighted average price: KRW 31,271 (2) Most recent 1-month volume-weighted average price: KRW 32,292 (3) Most recent 1-week volume-weighted average price: KRW 35,095 Reference purchase price [(1)+(2)+(3)/3]: KRW 32,886 Source: Korea Exchange Information Data System (http://data.krx.co.kr) As company to be merged Huons Lab Co., Ltd. is unlisted, its appraisal-right expected purchase price is the merger value of KRW 14,500. h. Under the relevant law, if the shareholders' meeting rejects approval of the merger, appraisal rights also lapse and the merger agreement does not take effect. i. A shareholder requesting appraisal rights may not cancel the request after the appraisal-rights exercise period ends. j. Business combination reporting is required for this merger and will proceed promptly after completion; as a merger between affiliated companies, it falls under the simplified-review category under the business combination review standards. k. The termination conditions in the merger agreement are summarized as follows. Article 13 (Conditions precedent): each party's obligation to carry out the merger is subject to lawful board/shareholders' meeting approval; completion of necessary measures and government/third-party approvals before the merger date; the other party's representations and warranties being true and accurate in all material respects; the other party having performed its covenants and obligations in all material respects; no material adverse effect on or change to either party's assets or business between the agreement date and the merger date; no law, government order, or court decision prohibiting or materially adversely affecting the merger having been issued; and all of Party B's redeemable convertible preferred shares having been converted to common shares as of the merger date. Article 14 (Termination): the parties may terminate by written agreement at any time before the merger date; either party may terminate by written notice if a material adverse circumstance is found; if a government approval material to the merger is denied or reasonably expected to be denied, or carries materially burdensome conditions; if the conditions precedent in Article 13 are determined incapable of being satisfied; if either party's representations/warranties are inaccurate and cause or are reasonably expected to cause a material adverse effect; or if either party breaches its covenants and fails to cure within 10 business days of a cure request. If, in connection with the merger, the aggregate appraisal-right purchase price for either party's shareholders exceeds a threshold (KRW 30 billion for Party A, KRW 4 billion for Party B) as of the expiration of the exercise period and that party's board resolves to halt the merger, the agreement terminates; termination does not affect either party's claims for damages or other remedies, and certain provisions (including Articles 14, 16 and 17) survive termination. l. No new merger shares will be allotted for treasury shares that Huons Lab Co., Ltd. comes to hold from its shareholders' exercise of appraisal rights, so the expected number of new merger shares above may change by the time the merger is finalized. m. In fulfilling directors' duty of loyalty under Article 382-3 of the Commercial Act and the Ministry of Justice's "Guidelines on Directors' Conduct in Corporate Restructuring," the merging companies operated a special committee composed of outside directors and obtained review from an independent external law firm. Huons Co., Ltd. formed a 3-member body (2 outside directors and 1 independent external attorney) performing the special committee's function, holding two meetings before the board resolution to review the merger's structure, transaction terms, basis for the merger ratio and procedural adequacy, hearing detailed explanations from and holding Q&A with independent external accounting and law firms, and requesting additional materials on the merger-ratio calculation method, key assumptions, post-integration financial-structure improvement potential and minority-shareholder protection measures. The special committee determined that the merger serves the interests of the Company and all shareholders and poses no risk of harming shareholder interests or having an unfair or discriminatory effect on minority shareholders. The board, considering the special committee's and external experts' review, determined that the merger's purpose and expected effects are reasonable, the transaction terms are fair and it conforms to relevant laws, and accordingly approved execution of this merger agreement. For details, please refer to the board minutes and board opinion attached to this report.

※ This disclosure supersedes the re-disclosure of the May 13, 2026 response (unconfirmed) to a request for confirmation of a rumor or media report.