Exploratory analysis of the impact of prior immune checkpoint inhibitor (ICI) on trastuzumab deruxtecan (T-DXd; DS-8201) clinical outcomes and biomarkers (BM) in DESTINY-Gastric01 (DG-01), a randomized, phase 2, multicenter, open-label study in patients (pts) with HER2+advanced gastric or gastroesophageal junction adenocarcinoma