Hong Kong-listed Alphamab Oncology (stock code: 09966, “ALPHAMAB-B”) announced that the Center for Drug Evaluation (CDE) of China’s National Medical Products Administration has formally accepted the Investigational New Drug (IND) application for JSKN021, a first-in-class dual-payload bispecific antibody-drug conjugate (ADC) targeting EGFR and HER3.

JSKN021 Profile • Structure: EGFR/HER3 bispecific antibody conjugated with two cytotoxic payloads—topoisomerase I inhibitor T01 (DAR 4) and monomethyl auristatin E (DAR 2). • Design Rationale: Tuned binding avidity aims to address tumor heterogeneity, enhance stability, improve homogeneity, and reduce on-target, off-tumor toxicity. • Preclinical Highlights: Data presented at the 2025 AACR annual meeting showed JSKN021 inhibited tumor growth in cell lines expressing EGFR, HER3, or both, and demonstrated stronger antitumor efficacy than mono-payload ADCs across multiple CDX models.

Clinical Development Plan The company intends to launch a Phase I study in patients with advanced malignant solid tumors. Key objectives include evaluating safety, tolerability, pharmacokinetics, antitumor activity, and determining the maximum tolerated dose or recommended Phase II dose.

Corporate Context Alphamab Oncology operates a fully integrated platform focused on ADCs, bispecific antibodies and multifunc­tional protein engineering. Its pipeline includes one NMPA-approved product and multiple late-stage assets.

Regulatory Note Acceptance of the IND does not guarantee eventual approval or commercialization. Investors are urged to exercise due caution when dealing in the company’s shares.