Astellas gives the Claudin18.2 pipeline a boost

Astellas’s zolbetuximab is the lead project against a popular target, Claudin18.2, so its apparent late-stage success today should bring cheer to the Japanese company and beyond. There is a host of other groups attempting to hit Claudin18.2, which is thought to be overexpressed on gastric and pancreatic cancers in particular. However, most players are at an early stage, and there has so far not been much big pharma involvement. The question now is whether this might change after the success of Astellas’s phase 3 Spotlight trial, which compared zolbetuximab plus mFolfox6 chemo against placebo plus mFolfox6 in first-line Claudin18.2-positive gastric cancers. All Astellas is saying is that the study hit both its primary endpoint of progression-free survival and a key secondary, overall survival. As always, the devil will be in the detail, and it is notable that in phase 2 zolbetuximab’s benefit was driven by patients with the highest Claudin18.2 levels, defined as expression of 70% or more. Zolbetuximab is Astellas’s most valuable R&D asset, with forecast 2028 sales of $522m, according to Evaluate Pharma sellside consensus. Data are also expected by year end from a second pivotal gastric cancer study, using a different chemo backbone.