Sonesitatug vedotin, a claudin 18.2-targeting antibody-drug conjugate, delivered a statistically meaningful overall survival benefit in previously treated advanced or metastatic CLDN18.2-positive gastroesophageal carcinoma, results from the phase 3 CLARITY-Gastric01 trial showed at ESMO Congress 2026. In patients treated in the third-line or later setting, median OS doubled to 10.0 months versus 5.0 months with investigator’s choice of therapy. The ADC did not significantly improve progression-free survival in the intention-to-treat population, where the hazard ratio was 0.77. Presenters emphasized the subgroup signal and positioned the data as support for a potential new standard in later lines, while noting the continued unmet need for CLDN18.2-directed options beyond first-line treatment.