A Prospective, Open-label, Single-arm, Exploratory Clinical Trial to Evaluate the Safety and Tolerability of 225Ac-TR2205 Injection in Patients With Triple-negative Breast Cancer.

This early-phase study is testing the safety of a new radioactive drug called 225Ac-TR2205 in women with metastatic triple-negative breast cancer — an aggressive form of breast cancer that lacks the three most common treatment targets. This type of therapy uses a radioactive particle attached to a molecule that seeks out tumour cells. **You may be eligible if...** - You are a woman aged 18 or older - You have been diagnosed with triple-negative breast cancer that has spread (metastatic) - You have already received at least 2 systemic treatments (at least one for metastatic disease) - Your cancer can be measured on a scan - You are in reasonably good physical condition (ECOG 0–1) - You are not pregnant and agree to use effective contraception **You may NOT be eligible if...** - You have significant unresolved side effects from previous treatments - Your general health does not meet the minimum requirements - You are breastfeeding or pregnant Talk to your doctor to see if this trial is right for you.