AZD6738 Plus Durvalumab in Biliary Tract Cancer

This study is testing two drugs — AZD6738 (a drug that blocks a DNA repair enzyme) and durvalumab (an immunotherapy drug) — together to treat bile duct and gallbladder cancers that have stopped responding to other treatments. **You may be eligible if...** - You are over 20 years old - You have a confirmed diagnosis of biliary tract cancer (including bile duct cancer, gallbladder cancer, or related cancers) - Your cancer cannot be surgically removed or has come back - Your cancer has already been treated with immunotherapy (and possibly chemotherapy) - You have at least one measurable tumor on imaging - You are generally active and in reasonably good health (ECOG 0 or 1) - Your life expectancy is more than 16 weeks **You may NOT be eligible if...** - Your cancer has not previously received immunotherapy treatment - You have serious heart, kidney, or liver problems - You have active autoimmune disease or are on immune-suppressing medications - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.