Posted: Monday, June 6, 2022
In the phase III TROPiCS-02 trial, heavily pretreated patients with endocrine-resistant, hormone receptor–positive, HER2-negative, unresectable locally advanced or metastatic breast cancer derived a progression-free survival benefit from treatment with sacituzumab govitecan-hziy versus single-agent chemotherapy. The primary results, which were presented by Hope S. Rugo, MD, FASCO, of the University of California San Francisco, and colleagues during the 2022 American Society of Clinical Oncology (ASCO) Annual Meeting (Abstract LBA1001), also showed a “numeric but nonsignificant difference in overall survival” with this anti–Trop-2 antibody-drug conjugate.
“This trial shows that sacituzumab govitecan, which is already approved for the treatment of metastatic triple-negative breast cancer, may represent an important new option for patients with endocrine-resistant, hormone receptor–positive/HER2-negative metastatic breast cancer,” stated ASCO breast cancer expert Jane Lowe Meisel, MD, of Emory University School of Medicine, Atlanta.
Patients were randomly assigned to receive sacituzumab govitecan (n = 272) or single-agent chemotherapy with capecitabine, eribulin, vinorelbine, or gemcitabine (n = 271). The median duration of progression-free survival was longer with sacituzumab govitecan than with chemotherapy (5.5 vs. 4.0 months; hazard ratio = 0.66; P = .0003); the rates of progression-free survival at 6 and 12 months were 46% versus 30% and 21% versus 7%, respectively. Overall survival was numerically but not significantly different between the arms (13.9 vs. 12.3 months; hazard ratio = 0.84; P = .143). The objective response rate (21% vs. 14%) and clinical benefit rate (34% vs. 22%) were higher with sacituzumab govitecan than with chemotherapy; the median durations of response were 7.4 and 5.6 months, respectively.
Treatment-emergent adverse events of grade 3 or higher were reported in 74% of the sacituzumab govitecan arm and 60% of the chemotherapy arm; neutropenia (51% vs. 39%) and diarrhea (10% vs. 1%) occurred most frequently. According to the investigators, the incidences of adverse events leading to the discontinuation of treatment were low with both sacituzumab govitecan and chemotherapy (6% vs. 4%). One treatment-related death occurred with sacituzumab govitecan; none were reported with chemotherapy.
Disclosure: For full disclosures of the study authors, visit coi.asco.org.