Material event report (merger)

What happened

Material Event Report (Decision on Company Merger) 6.1 DuChemBio Co., Ltd. Material Event Report / Matters Subject to KRX Reporting Obligations To the Financial Services Commission / Korea Exchange July 22, 2026 Company name: DuChemBio Co., Ltd. CEO: Kim Sang-woo Head office address: 6th and 7th floors, 81 Wausan-ro, Mapo-gu, Seoul Phone: 02-332-4868; Website: http://www.duchembio.com Preparer: Position Executive Managing Director, Name Kim Bong-seok, Phone 02-332-4686

Decision on Company Merger 1. Merger method: DuChemBio Co., Ltd. will absorb Radio D&S Labs Co., Ltd. - Surviving company: DuChemBio Co., Ltd. - Dissolved company: Radio D&S Labs Co., Ltd. Name of the surviving company after the merger: DuChemBio Co., Ltd. - Form of merger: Small-scale merger

2. Purpose of the merger: Enhancing corporate value by increasing management efficiency in the radiopharmaceutical business

3. Material effects and impact of the merger (a) Effect on the Company's management: In this merger, the surviving company is DuChemBio Co., Ltd. and the dissolved company is Radio D&S Labs Co., Ltd.; DuChemBio Co., Ltd. will absorb Radio D&S Labs Co., Ltd., which will be dissolved. The merger ratio is 1:0 (DuChemBio Co., Ltd. : Radio D&S Labs Co., Ltd.), and as this merger does not involve issuance of new shares, the merging company will not issue any new shares as a result of this merger. There will be no change in DuChemBio Co., Ltd.'s largest shareholder after completion of this merger. (b) Effect on the Company's finances and operations: Since the dissolved company is a wholly owned subsidiary 100%-owned by the surviving company, the impact on the consolidated financial position and operations upon completion of this merger is expected to be limited; however, synergies from organizational integration and improved management efficiency are expected.

4. Merger ratio: DuChemBio Co., Ltd. : Radio D&S Labs Co., Ltd. = 1.0000000 : 0.0000000 - In the case of a dissolution merger of a special purpose acquisition company, the multiple of the reference price on the listing date of the merger's new shares relative to the closing price on the last trading day of the special purpose acquisition company: Not applicable

5. Basis for calculating the merger ratio: The merging company, DuChemBio Co., Ltd., owns 100% of the shares of the merged company, Radio D&S Labs Co., Ltd., and since the merging company will not issue new shares for the shares of the merged company in the merger, the merger ratio is calculated as 1.0000000 : 0.0000000. - Corporate value: Surviving company -; Dissolved company -

6. Matters Concerning External Valuation Whether an external valuation was conducted: Not applicable Basis and reason: Pursuant to the proviso of Article 176-5, Paragraph 8, Item 2, Sub-item (b) of the Enforcement Decree of the Financial Investment Services and Capital Markets Act (which excludes the requirement for external valuation institution assessment of the appropriateness of the merger value when a company owning the total issued shares of another company merges with that company without issuing new shares), this merger falls under that exception, and accordingly no external valuation institution assessment was conducted pursuant to the above provision. Name of the external valuation institution: -; External valuation period: -; External valuation opinion: -

7. Type and number of new merger shares (shares): Common shares: -; Class shares: -

8. Merger counterparty Company name: Radio D&S Labs Co., Ltd. Main business: Radiopharmaceutical research and development Relationship with the Company: Subsidiary Financial details for the most recent fiscal year (KRW): Total assets: 83,140,638; Capital stock: 30,000,000; Total liabilities: 1,860,040; Revenue: 55,000,000; Total equity: 81,280,598; Net income: 22,544,032 - Whether externally audited: Institution name: -; Audit opinion: - - In the case of a dissolution merger of a special purpose acquisition company: CEO: -; Date of establishment: -; Head office address: -; Expected date of filing of the securities registration statement: -

9. Newly established merger company Company name: -; Financial details at establishment (KRW): Total assets: -; Total liabilities: -; Total equity: -; Capital stock: - - Revenue for the most recent fiscal year of the newly established business division as of the present (KRW): -; Main business: -; Whether re-listing will be applied for: Not applicable

10. Merger schedule Merger agreement date: July 23, 2026 Record date for confirming shareholders: August 6, 2026 Shareholder register closure period: Start date -; End date - Period for receiving notices of objection to the merger: Start date August 6, 2026; End date August 20, 2026 Expected date of general shareholders' meeting: - Appraisal rights exercise period: Start date -; End date - Old share certificate submission period: Start date -; End date - Expected trading suspension period: Start date -; End date - Creditor objection period: Start date September 1, 2026; End date October 1, 2026 Merger date: October 2, 2026 Merger completion report meeting date: October 2, 2026 Expected merger registration date: October 2, 2026 Expected date of delivery of new share certificates: -; Expected listing date of new shares: -

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

13. Matters Concerning Appraisal Rights Exercise requirements: As this proceeds under the small-scale merger procedure of Article 527-3 of the Commercial Act, appraisal rights are not granted to shareholders of DuChemBio Co., Ltd. Expected purchase price: -; Exercise procedures, method, period, location: -; Expected timing and method of payment: -; Matters concerning restrictions on appraisal rights: -; Effect on the contract: -

14. Board resolution date (decision date): July 22, 2026 - Attendance of outside directors: Present 1; Absent - - Attendance of the auditor (audit committee member who is not an outside director): Present

15. Whether a put option or similar contract was signed: No; Contract details: -

16. Whether subject to filing of a securities registration statement: No - Reason if exempted from filing: As this merger proceeds without issuing new merger shares (no-new-share merger method), there is no offering or sale of securities requiring filing of a securities registration statement.

17. Future plans for corporate restructuring: As of the date of this report, there are no confirmed matters regarding corporate restructuring that DuChemBio Co., Ltd. is pursuing or planning after completion of this merger.

18. Other material matters for investment decisions (1) As this merger is a small-scale merger under Article 527-3 of the Commercial Act, appraisal rights are not recognized, and approval of the merger is replaced by board approval. (2) Although this merger proceeds as a small-scale merger, pursuant to Article 527-3, Paragraph 4 of the Commercial Act, if shareholders holding 20% or more of the total issued shares of the merging company, DuChemBio Co., Ltd., give written notice of objection to the merger within two weeks from the date of the small-scale merger public notice, this merger cannot proceed as a small-scale merger. (3) The financial details for the most recent fiscal year of the "8. Merger counterparty" above are based on the financial statements as of the end of 2025. (4) The "merger completion report meeting" in "10. Merger schedule" above is planned to be replaced by a public notice procedure following a board resolution, pursuant to Article 526, Paragraph 3 of the Commercial Act. (5) "10. Merger schedule" above is the expected schedule as of the filing date of this disclosure, and may change according to approvals and permits under relevant laws and regulations and consultation with relevant authorities. Related disclosures: Not applicable.

[Detailed Statement of Material Matters Concerning the Merger] 1. Overview of the Merger (a) Basic matters concerning the merger (1) Merger counterparty Surviving company after merger: Name: DuChemBio Co., Ltd.; Location: 6th and 7th floors, 81 Wausan-ro, Mapo-gu, Seoul; CEO: Kim Sang-woo; Listing status: Company listed on the KOSDAQ market Dissolved company after merger: Name: Radio D&S Labs Co., Ltd.; Location: 5F, Room 501, 24 Yangpyeong-ro, Yeongdeungpo-gu, Seoul; CEO: Oh Seung-jun; Listing status: Unlisted company

(2) Background of the merger: Through this merger, the surviving company, DuChemBio Co., Ltd., seeks to improve management efficiency and strengthen business competitiveness by absorbing the dissolved company, Radio D&S Labs Co., Ltd. By absorbing Radio D&S Labs Co., Ltd., DuChemBio Co., Ltd. expects to be able to further accelerate its radiopharmaceutical CDMO business, a mid-to-long-term growth driver, and the development of new therapeutic radiopharmaceuticals. (3) Whether this constitutes a backdoor listing: Not applicable. (4) Material effects and impact on the Company's management, finances, and operations, etc.: Since the dissolved company, Radio D&S Labs Co., Ltd., is a wholly owned subsidiary 100%-owned by the surviving company, DuChemBio Co., Ltd., the impact on the consolidated financial position and operations upon completion of this merger is expected to be limited; however, synergies from organizational integration and improved management efficiency are expected. (5) Future plans for corporate restructuring: As of the date of this report, there are no confirmed matters regarding corporate restructuring that DuChemBio Co., Ltd. is pursuing or planning after the merger. Overview of the counterparty company: please refer to "2. Matters Concerning the Merger Counterparty Company" below. (as stated in the filing: both of these points are numbered "(5)" in the source) (6) Form of the merger: This is an absorption-type merger, and the surviving company after completion of the merger is DuChemBio Co., Ltd. As this falls under a small-scale merger under Article 527-3 of the Commercial Act, appraisal rights are not recognized, and since the merger ratio is 1:0 (a no-new-share absorption merger), no new shares will be issued as a result of this merger. If shareholders holding 20% or more of DuChemBio Co., Ltd.'s total issued shares give notice of objection to the merger, the merger cannot proceed. (7) Key schedule Classification / Date / Remarks: Merger decision board resolution date: July 22, 2026 / - Material event report filing date: July 22, 2026 / - Public notice of record date for confirming shareholders: July 22, 2026 / Posted on company website Merger agreement date: July 23, 2026 / - Record date for confirming shareholders (*1): August 6, 2026 / - Small-scale merger public notice: August 6, 2026 / Posted on company website Period for receiving notices of objection to the merger: Start date August 6, 2026 / -; End date August 20, 2026 / - Board resolution date approving the merger (*2): August 31, 2026 / In lieu of general shareholders' meeting Public notice for creditors to raise objections: September 1, 2026 / Posted on company website Creditor objection period: Start date September 1, 2026 / -; End date October 1, 2026 / - Merger date: October 2, 2026 / - Board resolution date on merger completion report (*3): October 2, 2026 / In lieu of report meeting Merger completion report public notice: October 2, 2026 / Posted on company website Expected merger registration date: October 2, 2026 / - (*1) This is the record date for determining shareholders with rights to express objection to the small-scale merger. (*2) DuChemBio Co., Ltd., the merging company, falls under a small-scale merger, so the shareholders' meeting for merger approval is replaced by a board resolution. (*3) The merger completion report meeting is planned to be replaced by a public notice procedure following a board resolution, pursuant to Article 526, Paragraph 3 of the Commercial Act. The above key merger schedule is the expected schedule as of the filing date of this report, and may change according to agreement between the merging companies, approvals and permits under relevant laws and regulations, and consultation with relevant authorities. (8) Whether a securities registration statement will be filed: Whether subject to filing: Not applicable; Reason if exempted from filing: No-new-share merger (9) Conditions for the merger to be completed: Please refer to "(c) Investment risk factors related to the merger - (1) Risk factors that could make completion of the merger difficult" below.

(b) Merger ratio and basis for calculation (1) Merger ratio and basis for calculation: Since the surviving company, DuChemBio Co., Ltd., owns 100% of the issued shares of the dissolved company, Radio D&S Labs Co., Ltd., this merger proceeds as a no-new-share merger with a merger ratio of 1:0, without issuing merger-related new shares. (2) Whether an external valuation was conducted: The proviso of Article 176-5, Paragraph 8, Item 2, Sub-item (b) of the Enforcement Decree of the Financial Investment Services and Capital Markets Act provides that an external valuation institution's assessment of the appropriateness of the merger value is not required when a company owning the total issued shares of another company merges with that company without issuing new shares; this merger falls under that provision, and accordingly no external valuation institution assessment was conducted pursuant to the above provision.

(c) Investment risk factors related to the merger (1) Risk factors that could make completion of the merger difficult Conditions for termination of the contract under the merger agreement, Article 17 (Amendment or Termination of the Agreement): (1) This Agreement may be terminated if any of the following occurs before the merger date: (a) Where both parties agree in writing to terminate this Agreement after its execution and before the merger date; (b) Where a small-scale merger becomes impossible because shareholders holding 20% or more of the total issued shares object; (c) Where one party breaches the terms of this Agreement and, despite being requested in writing by the other party to perform or cure the breach, fails to do so within 30 days, allowing the other party to terminate the Agreement. (2) If, between the execution date of this Agreement and the merger date, matters related to the terms of this Agreement violate relevant laws and regulations or accounting standards, or if a material change occurs in the property or management condition of either party due to force majeure, transfer of all or a material part of a business division, or other reasons, or if it is determined that the purpose of the merger has become difficult to achieve for other reasons, Party A and Party B may amend or terminate this Agreement by written agreement. (3) Party A and Party B may enter into separate agreements on matters requiring additional agreement for the merger, and such separate agreements shall be deemed part of this Agreement. (2) Matters concerning future listing plans or possibility of delisting of merger new shares: As DuChemBio Co., Ltd. owns 100% of the issued shares of Radio D&S Labs Co., Ltd., and this is a no-new-share merger method that does not issue merger new shares, this is not applicable. As this merger does not constitute a backdoor listing, there is no possibility of delisting as a result of this merger. (3) Risk factors to consider when investing in the relevant securities if the merger is completed: The merged company, Radio D&S Labs Co., Ltd., was already a consolidated subsidiary before the merger, and this merger will not have a significant effect on DuChemBio Co., Ltd.'s consolidated revenue and profit or loss; accordingly, it is determined there are no risk factors to consider when investing in the securities. (4) Matters concerning option or similar contracts with the merger counterparty or a third party: Not applicable.

(d) Matters Concerning Appraisal Rights: As the merger procedure for DuChemBio Co., Ltd. proceeds under the small-scale merger method pursuant to Article 527-3 of the Commercial Act, appraisal rights are not granted to shareholders of the merging company, DuChemBio Co., Ltd. In addition, since the merged company, Radio D&S Labs Co., Ltd., is a 100%-owned subsidiary of the merging company, DuChemBio Co., Ltd., no appraisal rights arise, and shareholders' meeting approval of the merger is replaced by board approval.

(e) Relationship Between the Merging Companies (1) Relationship between the merging companies: As of the date of this report, DuChemBio Co., Ltd. owns 100% of the shares of Radio D&S Labs Co., Ltd. Company name / Account item / Number of shares / Equity ratio: DuChemBio Co., Ltd. / Subsidiary / 6,000 shares / 100.00% (2) Interlocking directorates among executives: Not applicable. (3) Where the largest shareholder of one party is a related party of the other party: As of the date of this report, the merging company, DuChemBio Co., Ltd., owns 100% of the shares of the merged company, Radio D&S Labs Co., Ltd., as its largest shareholder, so the largest shareholder and related parties of one party constitute related parties of the other party. (4) Sales, purchases, and operating receivables/payables between the merging companies: Not applicable. (5) Debt guarantees and provision of collateral: Not applicable.

(f) Transactions with the Largest Shareholder of the Merging Companies: Not applicable.

(g) Other Matters Necessary for Investor Protection (1) Status of the largest shareholder's equity, etc.: As this merger is a no-new-share merger that does not issue merger new shares, there is no change in the largest shareholder's equity before and after the merger. (2) Changes in the Company's capital after the merger: As this merger is a no-new-share merger that does not issue merger new shares, there is no change in DuChemBio Co., Ltd.'s total issued shares or capital stock after the merger. (3) Management policy and executive composition after the merger: As of the date of this report, there are no plans regarding changes to the surviving company's future material management policy or method of executive composition after completion of this merger. (4) Business plans, etc.: The Company expects that this merger will enable it to further accelerate its radiopharmaceutical CDMO business, a mid-to-long-term growth driver, and the development of new therapeutic radiopharmaceuticals.

2. Matters Concerning the Merger Counterparty Company (1) Company overview Company name: Radio D&S Labs Co., Ltd. Representative: Oh Seung-jun Head office address: 5F, Room 501, 24 Yangpyeong-ro, Yeongdeungpo-gu, Seoul Industry: Radiopharmaceutical research and development Fiscal year-end month: December Date of establishment: April 24, 2024 Listing status of shares: Unlisted company

(2) Business description: Radio D&S Labs Co., Ltd. was established in April 2024. As of the date of this report, DuChemBio Co., Ltd. owns 100% of Radio D&S Labs Co., Ltd., and the company's main business is radiopharmaceutical research and development.

(3) Financial matters: As Radio D&S Labs Co., Ltd. was established in 2024, financial information for the most recent two years (2024-2025) is presented. 1) Summary statement of financial position for the most recent 2 years (Unit: KRW million) Item / Period 2 (December 31, 2025) / Period 1 (December 31, 2024): Current assets: 31 / 8 Non-current assets: 52 / 51 Total assets: 83 / 59 Current liabilities: 2 / - Non-current liabilities: - / - Total liabilities: 2 / - Total equity: 81 / 59

2) Summary income statement for the most recent 2 years (Unit: KRW million) Item / Period 2 (December 31, 2025) / Period 1 (December 31, 2024): Revenue: 55 / - Selling, general and administrative expenses: 28 / 6 Operating income: 27 / (6) Non-operating income: - / - Non-operating expenses: - / - Income before income tax: 27 / (6) Income tax, etc.: 4 / - Net income: 23 / (6)

(4) External auditor's audit opinion: Not applicable. (5) Matters concerning the board of directors and other corporate bodies: Radio D&S Labs Co., Ltd., as an unlisted company, has a board consisting of 1 in-house director and 1 auditor. There are no committees within the board. (6) Matters concerning shareholders: As of the date of this report, the shareholding status of Radio D&S Labs Co., Ltd. is as follows: Shareholder name / Number of shares held / Equity ratio: DuChemBio Co., Ltd. / 6,000 shares / 100.00% (7) Matters concerning executives and employees: As of the date of this report, Radio D&S Labs Co., Ltd. has 1 in-house director in office. (8) Matters concerning affiliated companies, etc.: The affiliated companies of both merging companies are the same as of the date of this report. The largest shareholder of the merging company, DuChemBio Co., Ltd., is Geo Young Co., Ltd., and the affiliated companies are as follows: Listing status / Number of companies / Company name (Corporate registration number): Listed / 1 / DuChemBio Co., Ltd. (110111-2647604) Unlisted / 26 / Joseonhye G.Y. Holdings Co., Ltd. (110111-7126017); Geo Young Co., Ltd. (110111-2533910); Carecamp Co., Ltd. (110111-1930068); Geo Young Networks Co., Ltd. (110111-3997686); Yeongnam Geo Young Co., Ltd. (174611-0000965); Gyeongnam Geo Young Co., Ltd. (190111-0020541); Daejeon Geo Young Co., Ltd. (161211-0017278); Gangwon Geo Young Co., Ltd. (140111-0005048); Namsan Pharm Co., Ltd. (110111-3334763); Honam Geo Young Co., Ltd. (210111-0069437); Jeju Geo Young Co., Ltd. (220111-0057232); Cresoti Co., Ltd. (110111-2813370); Geo Young Gyeongdong Co., Ltd. (151111-0001390); Byeondong Market Co., Ltd. (160111-0005888); Pharmpaymall Co., Ltd. (110111-4301274); NS Smart Co., Ltd. (110111-3024471); FC Gate Co., Ltd. (110111-1909807); Curelink Co., Ltd. (110111-6961993); Cyfrus Co., Ltd. (160111-0252265); Cyfrus Gwangju Co., Ltd. (200111-0449144); Cyfrus Cheonan Co., Ltd. (161511-0248637); Geo MD Korea Co., Ltd. (110111-2808602); Radio D&S Labs Co., Ltd. (110111-8930855); RS Solution Co., Ltd. (110111-9116587); Baekje Pharm Co., Ltd. (201111-0000531); Baekje Ethical Pharm Co., Ltd. (110111-0612576)

(9) Other matters necessary for investor protection: As of the date of this report, not applicable.