A Study of BL-B16D1 in Patients With Unresectable Locally Advanced or Metastatic Breast Cancer and Other Solid Tumors

This trial is testing a new drug called BL-B16D1 in people with advanced breast cancer or other solid tumors that cannot be surgically removed and have stopped responding to standard treatments. **You may be eligible if...** - You are 18–75 years old (or 18+ in later study phases) - You have advanced breast cancer or another solid tumor confirmed by biopsy - Your cancer cannot be removed by surgery and has stopped responding to standard treatment - You have at least one measurable tumor lesion - Your expected survival is at least 3 months - You can provide tumor tissue for testing **You may NOT be eligible if...** - You have uncontrolled cancer in the brain - You have severe organ dysfunction - You are pregnant or breastfeeding - You have had recent major surgery or other active cancer treatments Talk to your doctor to see if this trial is right for you.