Turn on cookies to sign in
Signing in saves your progress to your Curie account. We can only do that with cookies on — turn them on to continue.
Two antibody-drug conjugates (ADCs) targeting Claudin 18.2 (CLDN18.2) delivered significant survival improvements in previously treated gastroesophageal cancer at the 2026 ESMO Congress. Sonesitatug vedotin doubled median overall survival in third-line or later patients, while arcotatug tavatecan met both its PFS and OS primary endpoints. Both agents could reshape the treatment landscape for this hard-to-treat cancer.
Two CLDN18.2-targeted antibody-drug conjugates (ADCs) delivered impressive survival results in previously treated gastroesophageal cancer at the 2026 ESMO Congress in Madrid — offering new hope in a setting where options are scarce.
In the phase 3 CLARITY-Gastric01 trial, sonesitatug vedotin more than doubled median overall survival (OS) vs. standard-of-care therapy in third-line or later patients (10.0 vs. 5.0 months), cutting the risk of death by 53%. In the broader ITT population (second-line and beyond), median OS was 10.6 vs. 6.4 months. However, the co-primary endpoint of PFS by independent review narrowly missed statistical significance, and experts noted that second-line data complicated interpretation. Meanwhile, the phase 3 G-HOPE-001 trial showed arcotatug tavatecan met both primary endpoints — median PFS of 5.5 vs. 2.9 months and median OS of 10.2 vs. 6.9 months — in third-line CLDN18.2-positive, HER2-negative gastric/GEJ adenocarcinoma.
By the Numbers
Why it matters: With median OS under 6 months in the third-line gastroesophageal cancer setting, both ADCs represent potentially practice-changing advances for a patient population with very few effective options. Regulatory filings are already underway for arcotatug tavatecan in Japan and China.
