Alphamab Oncology (Alphamab) announced that Chief Executive Officer and Executive Director Dr. Xu Ting, together with members of senior management, acquired a total of 676,000 company shares on 4 June 2026 through on-market transactions.

• Transaction details ‑ Dr. Xu bought 554,000 shares. ‑ Management purchased an additional 122,000 shares across recent weeks, including 4 June. ‑ Aggregate consideration for the combined purchases reached HK$4.99 million, implying an average price of HK$7.375 per share.

• Resulting ownership ‑ Dr. Xu now directly and indirectly controls 314.29 million shares, representing approximately 32.4% of Alphamab’s issued share capital (excluding treasury shares). ‑ The company confirmed that its public float remains above the 25% threshold required under Hong Kong Listing Rule 8.08.

• Corporate actions and rationale ‑ Alphamab stated the insider buying reflects management’s confidence in the company’s long-term prospects. ‑ On the same day, the company repurchased 156,000 shares, underscoring its positive view of future business performance.

• Operational progress highlighted by management ‑ KN026 received Chinese marketing approval in May 2026 for second- and later-line HER2-positive gastric/ gastroesophageal junction cancer. ‑ Phase III data on KN026 as neoadjuvant therapy for HER2-positive breast cancer were presented at the 2026 ASCO Annual Meeting. ‑ Multiple registrational trials are advancing, including programs for KN026 (first-line HER2-positive breast cancer; neoadjuvant and adjuvant breast cancer; first-line HER2-positive gastric/GEJ cancer), JSKN003 (second-line HER2-positive breast cancer, HER2-low breast cancer, platinum-resistant ovarian cancer, and HER2-positive colorectal cancer), and JSKN016 (later-line triple-negative breast cancer). ‑ Early-stage antibody-drug conjugates JSKN022, JSKN027 and JSKN021 have enrolled more than 30 patients collectively, with preliminary safety and efficacy signals reported for JSKN022.

All insider transactions complied with Hong Kong’s Listing Rules and the Model Code for Securities Transactions by Directors of Listed Issuers. The company indicated that further share purchases by management could occur subject to regulatory requirements.