A Study of Trastuzumab DeRuxtecan for Patients With Advanced HER2-pOsitive GaStric or GastroesoPhageal Junction AdEnocarcinoma Who Have Received a PrIor Trastuzumab-based Regimen Accompanied by a Disease RegistrY of Patients Treated With Conventional Therapies (PROSPERITY)

This non-interventional study will investigate the effectiveness of T-DXd, the patients demographic and clinical characteristics, treatment patterns including prophylactic medications and interventions for reduction of serious adverse events (SAEs), serious adverse drug reactions (ADRs) and safety event of interest (SEIs), tolerability, and patient survey of T-DXd, in cases with advanced HER2-positive gastric or GEJ adenocarcinoma receiving T-DXd as second line of treatment and beyond treatment option. Patients will be treated according to the proposed indication statement in the Summary of Product Characteristics (SmPC). No investigational drug will be administered in this study.

Data on conventional therapy (including platinum-fluoropyrimidine doublet chemotherapy, nivolumab, ramucirumab-paclitaxel, ramucirumab monotherapy, taxane or irinotecan, and pembrolizumab monotherapy) will also be collected in a disease registry part of the study.