Alphamab Oncology announced that the U.S. Food and Drug Administration has granted investigational new drug approval for JSKN021, enabling the launch of an open-label, multicenter Phase I study (JSKN021-101) in patients with locally advanced or metastatic solid tumors that are relapsed, refractory, or lack approved therapies.

The trial will assess safety, tolerability, pharmacokinetics and preliminary anti-tumor activity. A corresponding study is already underway in China, where the first patient was dosed in June 2026 and early signs of efficacy have been observed during dose escalation.

JSKN021 is a first-in-class “2-in-1” bispecific antibody–drug conjugate targeting EGFR and HER3. Using glycosite-specific conjugation, the candidate links two distinct cytotoxic payloads—topoisomerase I inhibitor T01 (DAR 4) and Monomethyl auristatin E (DAR 2)—to predefined Fc glycan sites. Pre-clinical data show higher tumor inhibition and favorable tolerability compared with single-payload ADCs.

The U.S. IND marks a key milestone in the company’s international expansion strategy. Alphamab Oncology plans to advance JSKN021’s development concurrently in China and the United States while continuing to broaden its proprietary pipeline of ADCs, monoclonal antibodies and bispecific antibodies.

Founded in the PRC, Alphamab Oncology operates an integrated technology platform for antibody-based oncology therapies. The company has two products approved by China’s National Medical Products Administration and several additional candidates in Phase III or pivotal trials.