Study of Trastuzumab Deruxtecan for Adults With Advanced HER2-Positive Gastric or Gastroesophageal Junction Adenocarcinoma Who Have Had Prior Trastuzumab Treatment, Including a Registry of Patients on Conventional Therapies in Europe

What this Trial Is About

Researchers are evaluating trastuzumab deruxtecan T-DXd as a treatment for adult patients with advanced HER2-positive gastric or gastroesophageal junction GEJ adenocarcinoma who have previously received a trastuzumab-based regimen. This study aims to assess the real-world effectiveness of T-DXd, patient characteristics, treatment patterns, and safety in this population. It also includes data collection on patients receiving conventional therapies for exploratory comparison. This is a non-interventional observational study where patients receive T-DXd or conventional therapies as part of routine clinical care according to approved guidelines SmPC. No investigational drugs are given. The study tracks patients starting T-DXd as a second-line or later treatment and collects data on other therapies such as chemotherapy and immunotherapy used in clinical practice. Participants will be followed for up to approximately 2 years from baseline to monitor outcomes including time to next treatment, changes in treatment, physician-reported safety events, use of prophylactic treatments, and quality of life using validated questionnaires. Data on physician visits, treatment discontinuation, and safety events will also be collected to understand treatment tolerability and patient experience in a real-world setting.

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)