Study of AZD5863 in Adult Participants With Advanced or Metastatic Solid Tumors

This study is testing a new drug called AZD5863 in adults with advanced or metastatic solid tumors — specifically cancers of the stomach, esophagus, or pancreas that have a protein called CLDN18.2 on their surface. **You may be eligible if:** - You are 18 or older - You have confirmed advanced stomach, gastroesophageal junction, esophageal, or pancreatic cancer - Your tumor tests positive for a protein called CLDN18.2 - You have received at least one prior treatment for advanced/metastatic disease - You are in reasonably good health and your organs are functioning adequately **You may NOT be eligible if:** - You have active autoimmune disease - You have brain metastases within the past 3 months - You have an active infection including HIV, hepatitis B or C - You had a blood clot (DVT or pulmonary embolism) in the past 3 months - You need ongoing immune-suppressing medications - You had a severe reaction to prior T-cell therapy Talk to your doctor to see if this trial is right for you.