[Amended] Material event report (decision to sell own convertible bonds)

What happened

Material Event Report (Decision to Sell Own Convertible Bonds) 6.0

Adbiotech Co., Ltd.

Amendment Report September 3, 2026

1. Disclosure document being amended: Material Event Report (Decision to Sell Own Convertible Bonds) 2. Date of original submission of the disclosure document being amended: March 27, 2026 3. Amended items:

Item: 9. Date of receipt (scheduled) of sale proceeds; Reason for amendment: addition of an interim payment and change of final payment schedule; Before: 2026.09.03; After: 2026.09.08

Item: 13. Other matters for reference in investment decisions; Before: "2) '9. Date of receipt (scheduled) of sale proceeds' above is the final payment date, with details as follows: - Down payment 2026.03.27 KRW 165,000,000 / Final payment 2026.09.03 KRW 3,135,000,000"; After: "2) '9. Date of receipt (scheduled) of sale proceeds' above is the final payment date, with details as follows: - Down payment 2026.03.27 KRW 165,000,000 / Interim payment 2026.09.03 KRW 1,135,000,000 / Final payment 2026.09.08 KRW 2,000,000,000 - Bond transfer schedule: 2026.09.03: face value KRW 1,000,000,000; 2026.09.08: face value KRW 2,000,000,000"

Material Event Report / Korea Exchange Reporting Obligation To the Financial Services Commission / Korea Exchange March 27, 2026

Company name: Adbiotech Co., Ltd. Representative Directors: Kim Do-hyeong, Hwang Man-hoe Head office address: 39 Geodu-danji 1-gil, Dongnae-myeon, Chuncheon-si, Gangwon State (Phone) 070-4193-4006 (Website) http://www.adbiotech.com Person responsible for preparation: (Title) Managing Director (Name) Choi Kyung-min (Phone) 070-4193-4006

Decision to Sell Own Convertible Bonds

1. Type of bonds: series 7; type: unregistered unsecured private-placement convertible bonds 2. Bond issue date: 2025.07.03 3. Bond issuance method: private placement 4. Bond maturity date: 2030.07.03 5. Total face (electronically registered) amount of the bonds (KRW): 8,000,000,000 6. Acquisition details of the bonds subject to sale, acquired before maturity: face (electronically registered) amount of bonds subject to sale (KRW) 3,000,000,000; acquisition amount (KRW) 3,115,397,260; acquisition background: separate agreement with the bondholder 7. Sale decision date: 2026.03.27 8. Sale amount: amount (KRW) 3,300,000,000; basis for determination: determined through mutual consultation with the buyer, comprehensively considering the bond's interest rate and stock price conditions, etc. 9. Date of receipt (scheduled) of sale proceeds: 2026.09.08 10. Purpose of sale: securing operating funds and improving financial structure

11. Conversion matters Conversion ratio (%): 100 Conversion price as of the report date (KRW/share): 1,797 Type of shares to be issued upon conversion: Adbiotech Co., Ltd. registered common shares Number of shares: 1,669,449 Ratio to total shares outstanding (%): 7.82 Conversion request period: start date 2026.07.03; end date 2030.06.03

12. Whether subject to Fair Trade Commission filing: not applicable

13. Other matters for reference in investment decisions 1) "7. Sale decision date" above is the date of the board resolution. 2) "9. Date of receipt (scheduled) of sale proceeds" above is the final payment date, with details as follows: - Down payment 2026.03.27 KRW 165,000,000 / Interim payment 2026.09.03 KRW 1,135,000,000 / Final payment 2026.09.08 KRW 2,000,000,000 - Bond transfer schedule: 2026.09.03: face value KRW 1,000,000,000; 2026.09.08: face value KRW 2,000,000,000 3) "11. Conversion matters - Conversion price as of the report date (KRW/share)" above is the amount adjusted from the original conversion price following rights offerings paid in on November 19, 2025 and January 13, 2026. 4) "11. Conversion matters - Shares to be issued upon conversion - Ratio to total shares outstanding (%)" above is calculated as [number of voting shares to be issued / (total voting shares outstanding as of the acquisition date + number of voting shares to be issued)]. 5) Regarding the early-redemption put option: Bondholders of these bonds may request early redemption of all or part of the electronically registered amount of these bonds before maturity, on the date that is 1 year from the issue date of these bonds, namely July 3, 2026 (the "early redemption payment date"), and on each date falling every 3 months thereafter; provided that if an early redemption payment date is not a business day, the following business day shall be the early redemption payment date, and no interest shall accrue for the period after the original early redemption payment date.

(1) Early redemption payment dates and amounts requestable: July 3, 2026: 103.00% of the electronically registered amount October 3, 2026: 103.77% of the electronically registered amount January 3, 2027: 104.55% of the electronically registered amount April 3, 2027: 105.31% of the electronically registered amount July 3, 2027: 106.09% of the electronically registered amount October 3, 2027: 106.88% of the electronically registered amount January 3, 2028: 107.68% of the electronically registered amount April 3, 2028: 108.47% of the electronically registered amount July 3, 2028: 109.27% of the electronically registered amount October 3, 2028: 110.09% of the electronically registered amount January 3, 2029: 110.91% of the electronically registered amount April 3, 2029: 111.72% of the electronically registered amount July 3, 2029: 112.55% of the electronically registered amount October 3, 2029: 113.39% of the electronically registered amount January 3, 2030: 114.24% of the electronically registered amount April 3, 2030: 115.08% of the electronically registered amount

(2) Early redemption rate and request period: Bondholders must submit an early redemption request to the issuer from 60 days to 30 days before the early redemption payment date (the "early redemption request period"); if the end date of the request period is not a business day, it extends to the following business day.

Round 1: request period 2026-05-04 to 2026-06-03; payment date 2026-07-03; rate 103.00% Round 2: request period 2026-08-04 to 2026-09-03; payment date 2026-10-03; rate 103.77% Round 3: request period 2026-11-04 to 2026-12-04; payment date 2027-01-03; rate 104.55% Round 4: request period 2027-02-02 to 2027-03-04; payment date 2027-04-03; rate 105.31% Round 5: request period 2027-05-04 to 2027-06-03; payment date 2027-07-03; rate 106.09% Round 6: request period 2027-08-04 to 2027-09-03; payment date 2027-10-03; rate 106.88% Round 7: request period 2027-11-04 to 2027-12-04; payment date 2028-01-03; rate 107.68% Round 8: request period 2028-02-03 to 2028-03-04; payment date 2028-04-03; rate 108.47% Round 9: request period 2028-05-04 to 2028-06-03; payment date 2028-07-03; rate 109.27% Round 10: request period 2028-08-04 to 2028-09-03; payment date 2028-10-03; rate 110.09% Round 11: request period 2028-11-04 to 2028-12-04; payment date 2029-01-03; rate 110.91% Round 12: request period 2029-02-02 to 2029-03-04; payment date 2029-04-03; rate 111.72% Round 13: request period 2029-05-04 to 2029-06-03; payment date 2029-07-03; rate 112.55% Round 14: request period 2029-08-04 to 2029-09-03; payment date 2029-10-03; rate 113.39% Round 15: request period 2029-11-04 to 2029-12-04; payment date 2030-01-03; rate 114.24% Round 16: request period 2030-02-02 to 2030-03-04; payment date 2030-04-03; rate 115.08%

(3) Early redemption request location: the issuer's head office (4) Early redemption payment location: Industrial Bank of Korea, Chuncheon Branch (5) Early redemption request procedure: A bondholder wishing to exercise the early-redemption put option, if the bonds are electronically registered in a customer account, requests early redemption to the Korea Securities Depository through the account management institution with which the bondholder deals; if electronically registered in the bondholder's own account, the bondholder requests early redemption directly to the Korea Securities Depository, which then aggregates such requests and submits the early redemption request to the request location.

[Matters concerning the buyer] Buyer name: K Polaris Investment Partnership; Relationship to the company or largest shareholder: -; Selection process: selected considering the investor's payment capacity and timing in order to raise funds needed for the company's business operations; Transactions and plans within 6 months before and after the sale decision: -; Face amount of bonds purchased (KRW): 3,000,000,000; Note: -

[Where the buyer includes a corporation or an organization] (1) Basic information of the corporation or organization Name: K Polaris Investment Partnership; Number of investors: 4; Representative director (representative partner): Seong Jae-ik, 25%; Managing partner: Seong Jae-ik, 25%; Largest shareholder (largest contributor): -

(2) Key financial matters of the corporation or organization for its most recent fiscal year (unit: KRW million) Fiscal year: 2025, settlement month December Total assets: -; Revenue: -; Total liabilities: -; Net income/loss: -; Total equity: -; External auditor: -; Capital stock: -; Audit opinion: -