CStone Pharmaceuticals (CSTONE PHARMA-B) filed a Next Day Disclosure Return on 18 June 2026 detailing the latest tranche of its share-repurchase programme.

On-market action • 18 June 2026: 500,000 ordinary shares bought back on the Hong Kong Stock Exchange at prices between HK$4.54 and HK$4.63, for a total consideration of HK$2.31 million. • These shares are designated for cancellation.

Cumulative June activity pending cancellation • 15 June: 6,000 shares at HK$4.66 (VWAP) • 16 June: 1.33 million shares at HK$4.6826 (VWAP) • 17 June: 1.00 million shares at HK$4.6212 (VWAP) • 18 June: 0.50 million shares at HK$4.6287 (VWAP)

Total shares awaiting cancellation: 2.84 million, representing approximately 0.18 % of the company’s 1.60 billion issued shares. Aggregate cash outlay for the four-day repurchase sequence amounts to HK$13.19 million.

Capital structure Issued share capital stood unchanged at 1,600,749,183 shares before and after the 18 June transaction; the reduction will be reflected once the repurchased shares are formally cancelled.

Repurchase mandate utilisation • Shareholders authorised the board on 25 June 2025 to buy back up to 136.45 million shares. • To date, 2.84 million shares have been repurchased under this mandate, equating to 0.21 % of the authorised limit. • In line with Hong Kong listing rules, the company is restricted from issuing new shares or disposing of treasury shares until 18 July 2026.

All repurchases were executed in accordance with Main Board Rule 10.06(4)(a), and the company confirms no material changes to the previously filed explanatory statement dated 3 June 2025.