Sacituzumab govitecan (SG) is a new antibody-drug conjugate directed against the cell-surface antigen Trop-2. Characteristics of the linker connecting the payload SN-38 to the antibody allows SG to kill tumor cells expressing Trop-2 and also the adjacent tumor cells (bystander effect). SG showed efficacy and safety in several epithelial tumors. The phase III ASCENT trial led to the approval of SG (10 mg/kg, d1,8 q3w) in patients with advanced or metastatic triple-negative breast cancer (TNBC) who have received ≥2 prior systemic therapies, including ≥1 for metastatic disease. The phase III TROPiCS-02 trial in heavily pretreated advanced hormone receptor (HR)-positive breast cancer has recently shown an improvement in progression-free survival for patients treated with SG compared to single-agent chemotherapy. The phase III post-neoadjuvant SASCIA study in early high-risk TNBC and HR-positive breast cancer is currently recruiting patients.
Keywords: antibody–drug conjugate; early breast cancer; metastatic breast cancer; sacituzumab govitecan.
Sacituzumab govitecan is a new treatment for metastatic triple-negative breast cancer. Triple-negative means that the three most commonly identified proteins are not found on the surface of cancer cells (estrogen or progesterone receptor and high level of the protein HER2). Metastatic breast cancer indicates that the breast cancer has spread to other parts of the body. Sacituzumab govitecan is a monoclonal antibody, a therapeutic antibody or protein that can attach a specific target on the surface of cancer cells known as Trop-2. The antibody carries a medication known as SN-38, which is released within and around the cancer cells, causing the destruction of cancer cells. The ASCENT trial compared 3 acituzumab govitecan with chemotherapy, which is a treatment that kills cancer cells or stops them from dividing. The trial showed that patients with advanced triple-negative breast cancer who took sacituzumab govitecan lived longer than those who took a different chemotherapy regimen while on the study. The TROPiCS-02 trial showed that also patients with a metastatic cancer expressing estrogen or progesterone receptor, known as hormone-receptor positive breast cancer, derived benefit from sacituzumab govitecan. The SASCIA trial will define if patients with early breast cancer receiving sacituzumab govitecan after surgery might live longer without the recurrence of cancer. Early-stage breast cancer means that the cancer has not spread to other parts of the body and can be completely removed with surgery.