A Study of MR001 in Patients With Locally Recurrent or Metastatic Advanced Triple-Negative Breast Cancer (TNBC)

This study tests a new drug called MR001 for people with triple-negative breast cancer (TNBC) — a type of breast cancer that lacks common hormone and protein receptors, making it harder to treat. The study is for patients whose cancer has spread or come back after previous treatment. **You may be eligible if...** - You have been diagnosed with triple-negative breast cancer confirmed by lab testing - Your cancer has spread (metastatic) or come back locally after first or later lines of treatment - You have at least one measurable tumor on a scan - You are in good general health (ECOG score 0 or 1) - Your life expectancy is more than 3 months - Your liver, kidneys, and blood counts are within acceptable ranges **You may NOT be eligible if...** - You have a history of severe allergic reactions to similar types of drugs (like monoclonal antibodies) - You are currently on systemic immunosuppressant medications - You have certain active infections or other serious health conditions Talk to your doctor to see if this trial is right for you.