Reverse HER2-negative Immune Resistant Breast Cancer

This study is testing treatments to help overcome resistance to immunotherapy in people with metastatic or locally advanced breast cancer — specifically hormone receptor-positive (luminal) or triple-negative breast cancer — whose cancer has stopped responding to immunotherapy. **You may be eligible if...** - You have metastatic or locally advanced breast cancer (either hormone receptor-positive HER2-negative, or triple-negative) - Your cancer progressed or stopped responding to immunotherapy (combined with targeted therapy or chemotherapy) - You are in reasonably good functional health - Your organ function (blood, liver, kidneys) is adequate **You may NOT be eligible if...** - You have HER2-positive breast cancer - You have not received prior immunotherapy - You have serious active infections, autoimmune conditions, or other significant health issues - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.