ALPHAMAB-B (09966) presented the latest research progress on JSKN003 at the 2026 ESMO Congress.

ALPHAMAB-B (09966) announced that the latest research progress on JSKN003 was presented during the poster presentation at the 2026 ESMO Congress. The JSKN003 combination therapy demonstrated outstanding antitumor activity in first-line treatment of HER2+ GC/GEJ, with the Cohort B regimen standing out in particular: achieving a 100% ORR, with all patients achieving PR, while also offering a better safety profile. This is the first clinical evidence of an ADC combined with its parent antibody achieving enhanced efficacy. These data support continued patient enrollment and longer follow-up in this study. Extended follow-up data confirmed that JSKN003 can deliver robust and durable antitumor benefits in heavily pretreated PROC; regardless of HER2 expression level, patients achieved durable responses, with significant improvements in PFS and OS, an advantage closely associated with the excellent tolerability of JSKN003. A Phase III clinical study of JSKN003 in the all-comer PROC population is currently ongoing, and it is expected to become a novel treatment option capable of prolonging survival for these difficult-to-treat patients. It is reported that JSKN003-003 is a multicenter, open-label, multi-cohort Phase II clinical study designed to evaluate the safety and efficacy of JSKN003 combination therapy in first-line treatment of HER2+ unresectable locally advanced or metastatic GC/GEJ, or in perioperative treatment of resectable GC/GEJ.