Duality Biotherapeutics, Inc. (“DualityBio”) disclosed that on 3 June 2026 it executed a share repurchase and a simultaneous option-related share issuance, resulting in a net reduction of 28,300 ordinary shares in public circulation.

DualityBio bought back 37,100 shares on the Hong Kong Stock Exchange at prices ranging from HKD 199.60 to HKD 205.40, for a volume-weighted average cost of HKD 201.82 per share and a total cash outlay of HKD 7.49 million. All repurchased shares are being held as treasury stock, taking the treasury share balance to 221,400.

On the same day, 8,800 new shares were issued at HKD 201.71 per share following an option exercise under the company’s Pre-IPO Equity Incentive Plan (adopted 28 February 2021 and amended 25 June 2023).

After these transactions: • Issued shares (excluding treasury) decreased 0.03% to 90,400,514. • Total issued shares (including treasury) rose to 90,621,914.

The buyback was conducted under the repurchase mandate approved on 20 June 2025, which authorises up to 8.80 million shares. Cumulative repurchases under this mandate now total 221,400 shares, representing 0.25% of the share base at the time the mandate was granted. A 30-day moratorium on further share issues or treasury-share sales applies until 3 July 2026, in line with Hong Kong listing rules.