AstraZeneca's Sone-Ve cuts risk of death by 42% in Phase III gastric cancer trial

AstraZeneca reported on Oct 25 that sonesitatug vedotin (Sone-Ve), its experimental antibody-drug conjugate targeting Claudin 18.2, cut the risk of death by 42% versus investigator's choice of therapy in the CLARITY-Gastric01 Phase III trial in advanced gastric cancers, presented at the European Society for Medical Oncology Congress in Madrid [1].

• Among all 532 second-line-or-later patients, median overall survival was 10.6 months versus 6.4 months, a hazard ratio of 0.58 [1][2].
• In the third-line-and-later group, a primary endpoint, median survival doubled to 10.0 from 5.0 months, a 53% lower risk of death [1].
• Progression-free survival by blinded central review, the other primary endpoint, missed statistical significance at 4.2 versus 3.8 months [1][3].
• Severe treatment-related side effects hit 36.4% of Sone-Ve patients versus 44.8% on the comparator [1].
• The trial enrolled patients with Claudin 18.2 on at least 25% of tumor cells; the approved drug for this target requires 75% [2].

AstraZeneca expects $3 billion to $5 billion in peak sales; analysts' estimates are closer to $1 billion, Reuters reported [2]. Takeda's rival Claudin 18.2 drug, arcotatug tavatecan, met its progression-free survival goal in a Phase III trial in China and Japan [3]. A month earlier, AstraZeneca agreed to invest $2 billion in Summit Therapeutics and test Sone-Ve with Summit's ivonescimab [2].

Oncology research head Susan Galbraith said AstraZeneca is discussing the data with regulators [3]. AstraZeneca reports third-quarter and nine-month results at 07:00 GMT on Oct 30 [4].