[Amended] Material event report (merger) (subsidiary)

What happened

Amendment Report, dated August 4, 2026.

1. Disclosure document being amended: Material Event Report (Merger Decision) 2. Original filing date of the document being amended: May 18, 2026 3. Amended items:

Item 10 (Merger schedule), Reason: schedule postponed for the parent company's compliance procedures under the dual-listing guideline. Before amendment: Merger agreement date May 18, 2026; shareholder-confirmation record date July 30, 2026; register-of-shareholders closure period: not applicable; notice period for dissenting shareholders (appraisal rights): August 6, 2026, August 20, 2026; expected shareholders' meeting date: August 21, 2026; appraisal-rights exercise period: August 21, 2026, September 11, 2026; old share-certificate submission period: not applicable; expected trading-halt period: not applicable; creditor-objection period: August 21, 2026, September 22, 2026; merger effective date: September 23, 2026; completion-report meeting date: September 23, 2026; expected merger registration date: September 23, 2026; new share-certificate delivery date: not applicable; expected new-share listing date: October 12, 2026. After amendment: merger agreement date (May 18, 2026) and record date (July 30, 2026) unchanged; all remaining schedule items (closure period, dissent-notice period, shareholders' meeting date, appraisal-rights period, certificate submission, trading halt, creditor-objection period, merger date, completion meeting, registration date, certificate delivery, new-share listing date) become not yet determined.

Item 13 (Appraisal rights, exercise procedure, method, period, place), Reason: same schedule postponement. Before amendment, the filing set out the appraisal-rights procedure under Commercial Act Article 522-3 and Capital Markets Act Article 165-5, with dissent notices due by August 18, 2026 (3 business days before the shareholders' meeting), brokerage consolidation to the Korea Securities Depository (KSD) by August 19, 2026, and KSD notice to the companies by August 20, 2026; the dissent-notice period ran August 6, August 20, 2026, the meeting was set for August 21, 2026, and the appraisal-rights exercise period was August 21, September 11, 2026 (brokerage requests due by September 9, 2026, 2 business days before the period ended). Reception places were: for Huons Co., Ltd. (surviving company), shareholders of record at the Huons Global Building, Building A, 8th Floor, 17 Changeop-ro, Sujeong-gu, Seongnam-si, Gyeonggi-do (beneficial shareholders through their own securities firm); for Huons Lab Co., Ltd. (dissolved company), shareholders of record at the same building's 7th floor (beneficial shareholders through their own securities firm). After amendment: all specific dates above become not yet determined; the procedure description and reception places are otherwise unchanged. A note cautions that the purchase price and the exercise of appraisal rights may still change as the process proceeds.

Item 13 (Appraisal rights, expected payment timing and method), Reason: same schedule postponement. Before amendment: expected payment date for both Huons Co., Ltd. and Huons Lab Co., Ltd. was September 18, 2026 (subject to change due to the companies' circumstances). After amendment: both payment dates become not yet determined; still subject to change.

Item 18 (Other matters material to investment judgment), added note: this amendment reflects a schedule change; however, as of the amendment date (August 4, 2026), the revised schedule itself has not yet been fixed. Once the new schedule is determined, the companies will hold a further board resolution and re-file an additional amendment to this material event report.

----- Original Material Event Report (as first filed May 18, 2026) ----- Material Event Report / Korea Exchange Mandatory Disclosure, Material Management Matter of Subsidiary Huons Co., Ltd., submitted to the Financial Services Commission / Korea Exchange, dated May 18, 2026. Company: Huons Co., Ltd. CEO: Song Su-young. Head office: Huons Global Building, Building A, 8th Floor, 17 Changeop-ro, Sujeong-gu, Seongnam-si, Gyeonggi-do. Tel: 02-854-4700. Website: www.huons.com. Preparer: Disclosure Officer Kim Jeong-hoon, Tel: 02-854-4700.

Merger Decision

1. Method of merger: (a) Huons Co., Ltd. will absorb Huons Lab Co., Ltd. by merger. Surviving company (absorbing company): Huons Co., Ltd. (KOSDAQ-listed). Dissolved company (absorbed company): Huons Lab Co., Ltd. (unlisted). (b) The surviving company after the merger will remain named Huons Co., Ltd. Merger form: not applicable. 2. Purpose of the merger: to resolve the structural constraints of a thin new-drug pipeline to drive future growth and intensifying downward pressure on revenue and profitability from government drug-pricing reform, and to build a full biopharmaceutical value chain and strengthen R&D capability, positioning the combined company as a global pharma/bio company. 3. Material effects of the merger: (1) Management: Huons Co., Ltd. will remain listed after absorbing Huons Lab Co., Ltd. Other than the shareholding change from issuing 3,825,373 merger new shares (24.20%) to Huons Lab shareholders as of the merger record date, there is no change to the controlling shareholder or governance structure. (2) Finances: R&D expense will rise in the short term, but strengthening the clinical pipeline and maximizing management efficiency are expected to ultimately improve the financial structure and profitability; combining the two companies' technical expertise is expected to increase R&D capability and reduce duplicate investment and externally sourced costs by leveraging Huons's clinical personnel, know-how and production facilities. (3) Business: combining both companies' technology, expertise and experience is intended to strengthen the new-drug pipeline (synthetic and biologic new drugs) and raise corporate value. Huons Lab has completed a domestic marketing-authorization application for a finished drug product based on human-derived hyaluronidase; once its drug-diffusion platform technology is commercialized, synergy from Huons's infrastructure and sales organization is expected to increase revenue and reduce costs. (4) Shareholder value: management efficiency and synergy from the merger are expected to raise shareholder value over the long term. After the merger, Huons's existing generic-drug-centered business will be combined with Huons Lab's new-drug/biosimilar pipeline, securing strong R&D talent and original patents and strengthening long-term technology competitiveness and corporate value. 4. Merger ratio: Huons Co., Ltd. : Huons Lab Co., Ltd. = 1 : 0.4256943. (SPAC dissolution-merger multiple of the SPAC's last-trading-day closing price versus the merger new shares' listing-day base price: not applicable.) 5. Basis for the merger ratio: (1) Huons Co., Ltd. common-share merger value: for a listed company the merger value is in principle the market-price value, but under Capital Markets Act Enforcement Decree Article 176-5(1)(2)(a), if market value is lower than asset value, asset value may be used instead. Huons's market value was calculated under Article 176-5, using May 15, 2026 (the day before the earlier of the first board-resolution date and the first merger-agreement date, both May 18, 2026) as the base date, as the arithmetic mean of: (a) most recent 1-month volume-weighted average closing price: KRW 32,292; (b) most recent 1-week volume-weighted average closing price: KRW 35,095; (c) latest closing price: KRW 34,800; (d) arithmetic mean (a+b+c)/3 = KRW 34,062. No premium or discount was applied. Merger value: KRW 34,062. (2) Huons Lab Co., Ltd. common-share merger value: under Capital Markets Act Enforcement Decree Article 176-5 and Regulation on Issuance and Disclosure of Securities Article 5-13 and its Enforcement Rule Article 4, the merger value of an unlisted company is the weighted average of asset value and income value weighted 1 and 1.5 respectively ("intrinsic value"); relative value was reviewed for reference only but not computed, because fewer than three listed companies share Huons Lab's detailed KRX industry sub-classification. (a) Intrinsic value [(A×1+B×1.5)/2.5]: KRW 14,500, asset value (A): KRW 808; income value (B): KRW 23,628. (b) Relative value: not applicable. (c) Merger value: KRW 14,500. (See the attached external appraiser's opinion for further detail on the merger value.) As above, the merger ratio of Huons common stock to Huons Lab common stock was set at 1 : 0.4256943. For reference, Huons Lab currently has 817,617 redeemable convertible preferred shares outstanding, all to be converted into common stock before the merger date; under the contractual refixing terms, the total common shares to be issued on conversion is 905,420 shares. Enterprise value: surviving company KRW 408,051,349,230; dissolved company KRW 129,026,872,500. 6. External appraisal: Conducted: Yes. Basis/reason: because Huons, a listed company, applied the merger value calculated under Enforcement Decree Article 176-5(1)(2)(b) in merging with an unlisted company, an external appraiser reviewed the fairness of the merger value under Article 176-5(7)(2)(a). External appraiser: Ichon Accounting Corporation. Appraisal period: April 29, 2026~May 15, 2026. Appraiser's opinion (summary): Ichon Accounting Corporation reviewed the fairness of the merger ratio between KOSDAQ-listed Huons Co., Ltd. (surviving company) and unlisted Huons Lab Co., Ltd. (dissolved company), using each company's K-IFRS audited separate financial statements for FY2025 (ended December 31, 2025), stock-price data, Huons Lab's 16-year business plan (January 2026, December 2041), and the business reports of listed companies in the same KRX industry sub-classification as Huons Lab. The appraiser followed the FSS "External Appraisal Guidelines (June 2009)" and KICPA's "External Appraisal Performance Standards under the Capital Markets Act (November 2024)," and complied with relevant ethical requirements including the fairness provisions of the CPA code of ethics. The appraiser found the per-share value underlying the merger ratio to be KRW 34,062 for Huons (par value KRW 500) and in the range of KRW 12,671~14,672 for Huons Lab (par value KRW 500), implying a merger-ratio range of 1:0.3719819 to 1:0.4307447. The agreed ratio of 1:0.4256943 falls within this range and was judged appropriate; the review found no departure, in any material respect, from the merger-value calculation methods prescribed by Capital Markets Act Enforcement Decree Article 176-5 and Regulation on Issuance and Disclosure of Securities Article 5-13 and its Enforcement Rule Articles 4~8. 7. Type and number of merger new shares: common shares 3,825,373; special-class shares: none. 8. Merger counterparty: Company: Huons Lab Co., Ltd. Main business: biopharmaceutical R&D. Relationship to the company: affiliate. Most recent fiscal year financials (KRW): total assets 8,261,890,851; capital stock 4,040,394,000; total liabilities 10,062,942,137; revenue 83,816,403; total equity -1,801,051,286; net loss -10,189,367,413. External auditor: Samil PricewaterhouseCoopers; audit opinion: unqualified. (SPAC dissolution-merger fields, CEO, incorporation date, head office, securities-registration-statement filing date: not applicable.) 9. Newly incorporated merger company: not applicable (no new company formed). 10. Merger schedule (as originally filed, now superseded by the August 4, 2026 amendment above): merger agreement date May 18, 2026; shareholder-confirmation record date July 30, 2026; all remaining schedule items not yet determined at original filing. 11. Backdoor listing: not applicable. 12. Whether the other party meets backdoor-listing requirements: not applicable. 13. Appraisal rights: Exercise requirements: Under Commercial Act Article 522-3 and Capital Markets Act Article 165-5, a shareholder of record as of the shareholder-confirmation record date who notifies the company in writing of its dissent to the board's merger resolution by the day before the shareholders' meeting may request, within 20 days of the meeting's resolution date, that the company purchase all or part of its shares in writing stating the class and number of shares, provided the shares were acquired before the merger resolution was publicly disclosed, or the shareholder can otherwise prove a purchase contract, loan-termination, or other acquisition act occurred by the next business day after disclosure, and the shares are held continuously through the exercise date; shares sold and reacquired during that period lose the right, and once exercised the right cannot be withdrawn. A shareholder who approves the merger at the meeting after having given prior written notice of dissent loses the right. As a KOSDAQ-listed company, Huons must purchase the tendered shares within one month after the appraisal-rights exercise period ends. Expected purchase price: KRW 32,886. Exercise procedure/method/period/place: procedure under Commercial Act Article 522-3 and Capital Markets Act Article 165-5 as described in the amendment above; dissent notice through the shareholder's brokerage (if applicable) by 3 business days before the meeting, consolidated to KSD by 2 business days before, KSD notice to the company 1 business day before; request period August 6~20, 2026; meeting August 21, 2026; appraisal-rights exercise period August 21, September 11, 2026 (brokerage requests due 2 business days before period end); reception places as listed in the amendment above for each company. Expected payment timing/method: by transfer to the shareholder's registered bank account (shareholders of record) or to the shareholder's brokerage account (beneficial owners); expected payment date for both companies was September 18, 2026, subject to change. Restrictions on the right: as described under Commercial Act Article 522-3 above, no withdrawal once exercised; lost if the shareholder later votes for the merger. Effect on the contract: after each company's shareholders approve the merger, if the aggregate appraisal-rights purchase price exceeds KRW 30 billion for Huons or KRW 4 billion for Huons Lab (measured at the end of the exercise period), the relevant company's board may decide whether to proceed with the merger. 14. Board resolution date: May 18, 2026. Independent/outside directors present: 3; absent: 0. Audit committee member attendance: not stated. 15. Put-option or similar agreement: No. 16. Securities registration statement required: Yes (no exemption). 17. Future restructuring plans: none specifically decided as of this report; any future decision will be disclosed under the relevant rules. 18. Other matters material to investment judgment: (a) Under Commercial Act Articles 522 and 434, approval of the merger at the shareholders' meeting is a special resolution requiring at least two-thirds of the voting rights present and at least one-third of total issued shares; if this threshold is not met, the merger may fail. (b) Other than cash paid for fractional shares arising from the new-share allotment, no other consideration will be paid to shareholders of the merging companies. (c) Item 7 (type and number of merger new shares) may change depending on Huons Lab shareholders' exercise of appraisal rights and the treatment of fractional shares. (d) Huons Lab's financial figures under Item 8 are as of fiscal year-end 2025. (e) The schedule under Item 10 may change through consultation with/approval by relevant authorities and between the contracting parties. (f) The "completion-report meeting" in Item 10 is replaced, per Commercial Act Article 526(3), by a board-resolution public notice procedure. (g) Detail on the expected purchase price in Item 13: under Capital Markets Act Article 165-5(3), the purchase price is set by agreement between the shareholder and the company; absent agreement, the price is the market trading price calculated under Enforcement Decree Article 176-7(3). For Huons: price offered by the company for negotiation: KRW 32,886, based on the formula in Capital Markets Act Article 165-5 and Enforcement Decree Article 176-7; if no agreement is reached, the price is based on exchange trading prices under the same provisions, and a dissenting shareholder may apply to the court to determine the price. Calculation (base date May 15, 2026): (1) most recent 2-month volume-weighted average price KRW 31,271 (March 16~May 15, 2026); (2) most recent 1-month volume-weighted average price KRW 32,292 (April 16~May 15, 2026); (3) most recent 1-week volume-weighted average price KRW 35,095 (May 11~15, 2026); base purchase price [(1)+(2)+(3)]/3 = KRW 32,886. Daily closing price, volume and closing price × volume (unit: KRW, shares), source Korea Exchange Data System (data.krx.co.kr): 2026-05-15: close 34,800; volume 108,454; close×volume 3,774,199,200. 2026-05-14: close 34,850; volume 91,761; close×volume 3,197,870,850. 2026-05-13: close 36,050; volume 265,024; close×volume 9,554,115,200. 2026-05-12: close 35,250; volume 336,137; close×volume 11,848,829,250. 2026-05-11: close 34,250; volume 296,555; close×volume 10,157,008,750. 2026-05-08: close 30,250; volume 130,449; close×volume 3,946,082,250. 2026-05-07: close 28,850; volume 144,021; close×volume 4,155,005,850. 2026-05-06: close 27,450; volume 56,853; close×volume 1,560,614,850. 2026-05-04: close 26,450; volume 72,635; close×volume 1,921,195,750. 2026-04-30: close 26,400; volume 20,942; close×volume 552,868,800. 2026-04-29: close 26,700; volume 25,527; close×volume 681,570,900. 2026-04-28: close 26,700; volume 23,555; close×volume 628,918,500. 2026-04-27: close 26,800; volume 38,759; close×volume 1,038,741,200. 2026-04-24: close 26,850; volume 31,638; close×volume 849,480,300. 2026-04-23: close 26,600; volume 36,231; close×volume 963,744,600. 2026-04-22: close 26,700; volume 7,617; close×volume 203,373,900. 2026-04-21: close 26,500; volume 30,353; close×volume 804,354,500. 2026-04-20: close 27,000; volume 14,131; close×volume 381,537,000. 2026-04-17: close 27,350; volume 48,362; close×volume 1,322,700,700. 2026-04-16: close 27,300; volume 18,928; close×volume 516,734,400. 2026-04-15: close 26,800; volume 20,675; close×volume 554,090,000. 2026-04-14: close 26,300; volume 12,980; close×volume 341,374,000. 2026-04-13: close 26,050; volume 18,916; close×volume 492,761,800. 2026-04-10: close 25,850; volume 16,933; close×volume 437,718,050. 2026-04-09: close 25,350; volume 8,384; close×volume 212,534,400. 2026-04-08: close 25,250; volume 16,337; close×volume 412,509,250. 2026-04-07: close 24,750; volume 18,104; close×volume 448,074,000. 2026-04-06: close 25,000; volume 9,150; close×volume 228,750,000. 2026-04-03: close 25,300; volume 6,372; close×volume 161,211,600. 2026-04-02: close 25,450; volume 29,837; close×volume 759,351,650. 2026-04-01: close 26,300; volume 9,542; close×volume 250,954,600. 2026-03-31: close 25,350; volume 15,431; close×volume 391,175,850. 2026-03-30: close 25,750; volume 13,136; close×volume 338,252,000. 2026-03-27: close 26,250; volume 12,448; close×volume 326,760,000. 2026-03-26: close 26,250; volume 19,371; close×volume 508,488,750. 2026-03-25: close 26,400; volume 20,487; close×volume 540,856,800. 2026-03-24: close 25,950; volume 14,833; close×volume 384,916,350. 2026-03-23: close 25,450; volume 15,526; close×volume 395,136,700. 2026-03-20: close 26,300; volume 15,507; close×volume 407,834,100. 2026-03-19: close 25,900; volume 13,057; close×volume 338,176,300. 2026-03-18: close 26,350; volume 11,119; close×volume 292,985,650. 2026-03-17: close 26,300; volume 10,254; close×volume 269,680,200. 2026-03-16: close 26,150; volume 11,541; close×volume 301,797,150. (1) 2-month volume-weighted average closing price: KRW 31,271. (2) 1-month: KRW 32,292. (3) 1-week: KRW 35,095. Base purchase price [(1)+(2)+(3)]/3: KRW 32,886. For Huons Lab (unlisted), the appraisal-rights purchase price is the merger value, KRW 14,500. (h) If the shareholders' meeting rejects the merger, the appraisal right also lapses and the merger agreement does not take effect. (i) A shareholder cannot withdraw an appraisal-rights request after the exercise period ends. (j) Merger-control (antitrust) filing is required and will be made promptly after the merger completes; as a merger between affiliates, it qualifies for simplified review under the merger-control review standards. (k) Termination conditions in the merger agreement (key excerpts): Article 13 (Conditions precedent) makes each party's obligation to complete the merger conditional on, by the merger date (waivable in writing): due board/shareholder approval of the merger by each party; completion of all necessary measures and government/third-party approvals before the merger date; the other party's representations and warranties remaining true and accurate; the other party having performed its covenants; no material adverse change to either party's assets or business since signing; no prohibiting or materially adverse law, government order or court decision having been issued since signing; and all of Huons Lab's redeemable convertible preferred shares having been converted into common stock by the merger date. Article 14 (Termination) allows termination by written agreement at any time before the merger date, or immediate termination by either party on written notice if: a material adverse circumstance arises; a required government approval material to the merger is denied or subject to unworkable conditions; a condition precedent becomes incapable of being satisfied; either party's representations/warranties prove materially inaccurate; or either party breaches a covenant and fails to cure it within 10 business days of written notice (a party responsible for the triggering event may not invoke it to terminate). The agreement also terminates if the aggregate appraisal-rights purchase price for either party's dissenting shareholders exceeds, by the end of the exercise period, KRW 30 billion for Huons or KRW 4 billion for Huons Lab and that party's board resolves to halt the merger. Termination does not affect either party's damages claims or other remedies, and provisions intended to survive termination (including Articles 14, 16 and 17) remain in effect. (l) Because no merger new shares will be allotted for treasury shares Huons Lab acquires through its own shareholders' appraisal-rights exercise, the number of merger new shares to be issued (Item 7) may change by the final merger date. (m) To fulfill directors' duty of loyalty under Commercial Act Article 382-3 and the fairness measures under the Ministry of Justice's "Guidelines on Director Conduct in Corporate Restructuring," the merging companies operated a special committee of outside directors and obtained review by an independent external expert (a law firm) to ensure the fairness and procedural adequacy of the merger. Huons's special committee comprised two outside directors and one independent external expert (an attorney) and held two meetings before the board resolution, closely reviewing the merger structure, deal terms, basis for the merger ratio, and procedural adequacy, including Q&A with the independent accounting firm and law firm and requests for further explanation on the merger-ratio methodology, key assumptions, post-merger financial-structure improvement, and minority-shareholder protection. The special committee concluded that the merger serves the interests of the company and all shareholders and poses no risk of unfairly or discriminatorily affecting minority shareholders; the board, after considering the committee's and external experts' review, concluded the merger's purpose and effects are reasonable, the deal terms are fair, and it complies with applicable law, and approved the merger agreement. See the board minutes and board opinion attached to this report for further detail. ※ Further detail on the merger will be provided in the company's forthcoming securities registration statement. ※ This filing also serves as the re-disclosure called for by the May 13, 2026 response to a rumor/media-inquiry request (undetermined at that time). ※ This amendment reflects a schedule change; as of the amendment date (August 4, 2026) the revised schedule has not yet been fixed. Once fixed, the companies will hold a further board resolution and re-file an additional amendment.

(condensed translation)