664PPhase I/II study of single agent MCLA-128, a full length IgG1 bispecific antibody targeting the HER3 pathway: Overall safety at the recommended phase II dose (R2PD) and preliminary activity in HER2+ metastatic gastric/gastroesophageal junction cancer (GC/GEJ). (23rd October 2018) - Alsina, M; Varga, A; Amatu, A; Schellens, J H M; Witteveen, P O; Boni, V; Moreno, V; Bol, K; Lourbakos, A; Magin Ferrer, M; Wasserman, E