LM-108 in Combination With PD-1 Based Treatment for Patients With Recurrent or Metastatic Triple - Negative Breast Cancer

This study tests LM-108 (an experimental antibody-drug treatment) combined with a PD-1 immune checkpoint drug for people with advanced or metastatic triple-negative breast cancer (TNBC) — a type of breast cancer that does not respond to hormone therapies and is harder to treat. **You may be eligible if...** - You are between 18 and 75 years old - You have confirmed advanced or metastatic triple-negative breast cancer - Cohort 1: you have had at least one prior treatment for metastatic disease - Cohort 2: you have had no prior treatment for metastatic disease and your tumor is PD-L1 positive - You have at least one measurable tumor on scans - Your organs and blood counts are within acceptable ranges **You may NOT be eligible if...** - You have active brain metastases - You have a serious autoimmune disease or are on long-term steroids - You have had a major heart event in the past 6 months - You are pregnant or breastfeeding Talk to your doctor to see if this trial is right for you.