Alphamab Oncology (stock code: 09966, “ALPHAMAB-B”) disclosed that the first patient has been dosed in its Phase III clinical study (JSKN016-301) evaluating JSKN016, a bispecific antibody–drug conjugate (ADC) targeting TROP2 and HER3, for the treatment of triple-negative breast cancer (TNBC).

The open-label, randomized, controlled, multicenter trial will span roughly 60 sites across mainland China and enroll patients with unresectable locally advanced, recurrent or metastatic TNBC who have failed at least two prior systemic regimens. Participants will receive either JSKN016 or a treatment of physician’s choice. Progression-free survival (PFS) and overall survival (OS), assessed by a Blinded Independent Review Committee under RECIST v1.1, serve as co-primary endpoints. Key secondary metrics include investigator-assessed PFS, objective response rate (ORR), disease control rate (DCR) and duration of response (DoR).

TNBC represents about 15%–20% of all breast-cancer cases. Current post-chemotherapy options typically yield an ORR near 10%–20% and a median PFS of one to three months, underscoring the need for more effective therapies.

JSKN016 is built on Alphamab’s proprietary glycan-specific conjugation platform. Following binding to TROP2 or HER3, the ADC internalizes and releases a topoisomerase I inhibitor within lysosomes, inducing tumor-cell death and exerting a bystander effect on adjacent antigen-negative cells. Pre-clinical and early-stage clinical studies have shown promising anti-tumor activity and a manageable safety profile across several solid-tumor types.

Alphamab Oncology operates a fully integrated platform covering ADCs, bispecific antibodies and multi-functional protein engineering. Its pipeline comprises one National Medical Products Administration-approved product and multiple assets in Phase III or pivotal studies.

In accordance with Rule 18A.05 of the Hong Kong Listing Rules, Alphamab cautions that successful development and commercialization of JSKN016 are not guaranteed. Shareholders and prospective investors are advised to exercise due care in dealing in the company’s securities.