Trop-2 Expression and Sacituzumab Govitecan in Triple-Negative Breast Cancer
Posted: Monday, January 4, 2021
Sara A. Hurvitz, MD, of the Jonsson Comprehensive Cancer Center, Los Angeles, and colleagues conducted a study to gain insights into the relationship between Trop-2 expression and the activity of the antibody-drug conjuate sacituzumab govitecan in patients with metastatic triple-negative breast cancer. They reported that sacituzumab govitecan was more beneficial than the physician’s choice of therapy in this patient population. However, the greatest benefit was observed in those who had medium or high Trop-2 expression. These findings from the phase III ASCENT trial were presented at the 2020 San Antonio Breast Cancer Symposium (SABCS; Abstract GS3-06).
This study is a phase III, open-label, global, multicenter trial that enrolled 529 participants with metastatic triple-negative breast cancer. Patients were either resistant to or had a relapse after two or more chemotherapies and were randomly assigned to receive either 10 mg/kg intravenously of sacituzumab govitecan for days 1 and 8 every 21 days or a single-agent treatment based on the choice of their physician (eg, eribulin, capecitabine, gemcitabine, or vinorelbine).
A total of 468 patients were evaluable by the point of data cutoff in the exploratory biomarker assessment. Of the 151 patients with known Trop-2 expression status who received sacituzumab govitecan, 56% had high expression tumors, 26% had medium expression tumors, and 23% had tumors of low expression. In those with high Trop-2 expression, the median progression-free survival was 6.9 months with sacituzumab govitecan versus 2.5 months without; it was lower in those with medium and low Trop-2 expression (5.6 months vs. 2.2 months and 2.7 months vs. 1.6 months, respectively). Similar findings were noted in overall survival. The median overall survival was 14.2 months with sacituzumab govitecan versus 6.9 months without in the group with high Trop-2 expression; it was lower in those with low Trop-2 expression (9.3 months vs. 7.6 months).
Disclosure: For full disclosures of study authors, visit sabcs.org.