AstraZeneca's stomach cancer drug clears bar for extending overall survival in late-stage study

In a 532-patient late-stage study, patients who had received at least two prior treatments lived a median of 10 months on sone-ve, compared with 5 months on their doctor's choice of chemotherapy. The results represented a 53% reduction in the risk of death. AstraZeneca oncology executive Susan Galbraith called the five-month improvement clinically significant in a difficult-to-treat population.

The study enrolled patients whose tumours had at least 25% claudin 18.2, while the approved treatment for the target requires a 75% cutoff. Galbraith said the lower threshold could double the number of eligible patients and support testing the drug earlier in treatment; a study of more than 2,000 patients is already evaluating it in an earlier setting. Progression-free survival, a co-primary goal, did not reach statistical significance: median results were 4.2 months with sone-ve and 3.8 months with chemotherapy. Serious side effects occurred in 36.4% of patients on sone-ve versus 44.8% on chemotherapy, while stomach-related side effects were more frequent with the drug.