The antibody-drug conjugate sacituzumab govitecan-hziy continued to demonstrate superior benefit for patients with hormone receptor–positive, HER2-negative metastatic breast cancer when compared with standard chemotherapy, according to the final analysis of the phase III TROPiCS-02 study published by Rugo et al in The Lancet.
Background
Sacituzumab govitecan comprises an antibody that targets the cell receptor Trop-2, which is abundant in solid tumors such as breast cancer, and the cancer agent SN-38. It has previously shown encouraging activity in early-phase clinical trials in patients whose metastatic breast cancer had progressed after at least two prior chemotherapies.
Previous data from the phase III TROPiCS-02 clinical trial—presented at the 2022 ASCO Annual Meeting and the European Society for Medical Oncology Congress—led to the U.S. Food and Drug Administration (FDA) approval of sacituzumab govitecan for the treatment of patients with hormone receptor–positive, HER2-negative breast cancer in February 2023.
Study Methods and Results
In the second analysis of the TROPiCS-02 study, investigators examined the data of 543 patients with hormone receptor–positive, HER2-negative metastatic breast cancer—who had been previously treated with endocrine therapy and chemotherapy—who were randomly assigned to receive either sacituzumab govitecan or chemotherapy.
The investigators found that the patients who received sacituzumab govitecan achieved an overall survival of 14.4 months compared with 11.2 months among those who received chemotherapy. The sacituzumab govitecan group also showed superior response rates as well as prolonged median progression-free survival when compared with the chemotherapy group. The investigators highlighted that the patients treated with sacituzumab govitecan had a 34% lower risk of cancer progression or mortality compared with those treated with chemotherapy.
The investigators reported that the most common adverse effects of treatment were neutropenia, diarrhea, nausea, alopecia, fatigue, and anemia—all of which occurred at a higher rate in patients in the sacituzumab govitecan group than in the chemotherapy group.
Conclusions
“These data reinforce that sacituzumab [govitecan] is leading to improvements in both progression-free [survival] and overall survival and that patients saw benefit irrespective of their tumor’s Trop-2 expression,” emphasized senior study author Sara Tolaney, MD, MPH, Chief of the Division of Breast Oncology at the Susan F. Smith Center for Women’s Cancers at the Dana-Farber Cancer Institute. “This updated analysis continues to support sacituzumab [govitecan] as a standard treatment for patients with pretreated, endocrine-resistant [hormone receptor–positive], HER2-[negative] metastatic breast cancer,” she concluded.
Disclosure: The research in this study was funded by Gilead. For full disclosures of the study authors, visit thelancet.com.
