It was hardly rocket science that Jupiter moon-named Ganymed Pharmaceuticals AG's claudin 18.2-targeting antibody – the one that created so much buzz at this year's American Society of Clinical Oncology (ASCO) meeting – would draw big pharma's top cancer players to the table. And Tokyo-based winner Astellas Pharma Inc.'s potential $1.4 billion takeover, with €422 million (US$461.3 million) up front plus another €860 million if progress milestones are met, gets not only the IMAB362 antibody but also Claudetect 18.2, an in vitro diagnostic for the biomarkers in patients most likely to be helped.