Sacituzumab govitecan — a new therapy for patients with triple-negative breast cancer

Treatment outcomes in patients with metastatic triple-negative breast cancer (TNBC) have not improved significantly for many years. Modern treatments, including immune therapy and poly ADP-ribose polymerase (PARP) inhibitors, are available for a select group of TNBC patients. In many cases, classic chemotherapy remains the treatment of choice, which produces unsatisfactory response rates. The poor prognosis of patients with metastatic TNBC justifies intensive research on new drugs for this group of patients, including attempts to use conjugates. This article discusses the reports on sacituzumab govitecan (SG), which is composed of a monoclonal antibody targeting trophoblast-cell surface antigen 2 (Trop-2) expressed on many TNBC cells and linked to a payload (SN-38), the active metabolite of irinotecan. The structure and mechanism of action of this conjugate are presented. The available results of clinical trials with SG in breast cancer patients are summarized, including the results of the ASCENT registration study, which showed a significant improvement in the median progression-free survival, as well as overall survival, compared to classic chemotherapy in patients previously treated with advanced TNBC. The most common side effects of the drug are discussed, indicating principles of primary and secondary prophylaxis that allow for effective management of possible complications. Directions for further research in breast cancer patients on this very promising conjugate were also indicated.