China Healthcare: Positive Ph3 data validate CLDN18.2 ADCs; Sone-Ve differentiates in patient breadth, IBI343 leads on efficacy depth

At ESMO 2026, Keymed/AstraZeneca and Innovent/Takeda presented positive Ph3 data for Sone-Ve and IBI343, respectively, in previously treated CLDN18.2+ gastric/GEJ cancer. Sone-Ve showed a strong 3L+ OS benefit (10.0 vs. 5.0 months; HR 0.47), although the co-primary BICR-PFS endpoint in the broader 2L+ population narrowly missed the prespecified statistical threshold (4.2 vs. 3.8 months; HR 0.77; p=0.053). IBI343 delivered a more consistent efficacy profile in a more biomarker-enriched 3L+ population, with PFS of 7.1 vs. 3.1 months (HR 0.45), OS of 10.2 vs. 6.9 months (HR 0.57) and cORR of 37.4% vs. 7.7%, meeting both primary endpoints. We see IBI343 as stronger on efficacy depth, particularly response/PFS, while Sone-Ve demonstrated meaningful survival benefit across a broader numerical CLDN18.2 expression range. Cross-trial comparison remains limited by differences in assays, biomarker definitions and treatment-line mix.