ALPHAMAB-B (09966.HK) JSKN021 bispecific ADC cleared by FDA for Phase I

NewTimeSpace News: On 2 November 2026, ALPHAMAB ONCOLOGY (ALPHAMAB-B, 09966.HK) disclosed that the US Food and Drug Administration (FDA) has cleared the investigational new drug application (IND) for JSKN021, its self-developed drug, to proceed with a Phase I clinical study, marking the official launch of the drug's overseas clinical development.

JSKN021 is a "2-in-1" bispecific antibody dual-payload ADC targeting EGFR/HER3, using site-specific glycan conjugation to attach two different cytotoxic payloads precisely to the antibody Fc glycans, producing a highly stable, low-hydrophobicity conjugate. By combining the topoisomerase I inhibitor T01 at DAR 4 with monomethyl auristatin E (MMAE) at DAR 2, it aims to overcome the non-response and resistance seen with single-payload strategies, with preclinical studies showing markedly superior tumour inhibition to single-payload ADCs.

The approved JSKN021-101 is an open, multi-centre Phase I study enrolling patients with locally advanced or metastatic solid tumours who have relapsed or are refractory after standard therapy, or who have no approved therapy. The study was previously approved in China, with the first patient dosed in June 2026 and preliminary efficacy observed during dose escalation. The company cautioned there is no guarantee it will ultimately develop and commercialise JSKN021.