D9802C00001 (CLARITY GC01): A Phase III Multi-center, Open-label, Sponsor-blinded, Randomized Study of AZD0901 Monotherapy Compared with Investigator’s Choice of Therapy in Second- or Later-Line Adult Participants with Advanced/Metastatic Gastric or Gastroesophageal Junction Adenocarcinoma Expressing Claudin18.2

We are doing this study to learn more about: the effectiveness and safety of the investigational study drug AZD0901 compared to a standard therapy that will be selected by your study doctor per your disease status (from a choice of ramucirumab + paclitaxel, paclitaxel, docetaxel, irinotecan, or TAS-102; thereafter referred as to Investigator’s Choice of Therapy) and also to better understand the studied disease and associated health problems. AZD0901 is a type of drug known as an Antibody Drug Conjugate (abbreviated to ADC). ADCs are a type of targeted therapy that deliver anti-cancer drugs directly to cancer cells. AZD0901 recognizes cancer cells by specific protein called Claudin 18.2 (CLDN 18.2). CLDN 18.2 is one of the proteins that is expressed on the surface of gastric cancer cells. AZD0901 binds to CLDN18.2 on the cancer cell surface and is taken into the cell where it releases the anti-cancer drug to stop the cell from reproducing and to cause the cancer cell to die. All parts of this study are experimental. AZD0901 is currently not approved by any health authority, such as the Food and Drug Administration (FDA). AZD0901 is also being tested in other ongoing studies.