Sinomab Bio-B (Sinomab Bioscience Limited) filed its Monthly Return for the period ended 31 May 2026, confirming no changes in share capital and continued adherence to Hong Kong Main Board public-float rules.

• Share capital stability – Issued ordinary shares (excluding treasury shares) stood at 1.39 billion, unchanged from the end of April 2026. – The company held no treasury shares, leaving total issued shares likewise unchanged at 1.39 billion.

• Public-float sufficiency – Management affirmed compliance with the minimum 25% public-float requirement under Main Board Rule 13.32D(1).

• Equity incentive position – The 2022 Share Option Scheme, approved on 26 October 2022 and amended on 14 June 2024, had 80.58 million outstanding options, identical to the prior month. – No options were exercised in May; consequently, no new shares were issued and no funds were raised. – At month-end, 16.93 million additional shares remained available for future grants, while the scheme’s total potential issuance capacity was 40.95 million shares.

No warrants, convertible securities, share repurchases, or other equity-related transactions were reported during the month.

The filing was authorised by Executive Director, Chairman and Chief Executive Officer Mr Shui On Leung and submitted to Hong Kong Exchanges and Clearing Limited on 4 June 2026.