medwireNews: Among people with endocrine-resistant, hormone receptor-positive, HER2-negative (HR+, HER2–) advanced breast cancer, sacituzumab govitecan is associated with significantly improved overall survival (OS) relative to standard of care, show data from TROPiCS-02.
The phase 3 trial previously showed a significant progression-free survival (PFS) benefit and a trend toward improvement of OS with the use of the first-in-class anti-Trop-2 antibody–drug conjugate in this population of heavily pretreated patients, said investigator Hope Rugo (University of California San Francisco, USA) at the ESMO Congress 2022 in Paris, France.
Hope Rugo outlines the latest results from the TROPiCS-02 trial of sacituzumab govitecan in hormone receptor-positive, HER2-negative advanced breast cancer and discusses where the antibody–drug conjugate fits into the treatment paradigm (4:42).
The current presentation focused on the second interim analysis for OS, which was conducted at a median follow-up of 12.5 months and demonstrated that OS was significantly prolonged for the 272 participants who were randomly allocated to receive sacituzumab govitecan 10 mg/kg on days 1 and 8 of every 21-day cycle compared with the 271 patients who instead received physician’s choice of capecitabine, vinorelbine, gemcitabine, or eribulin.
The median OS durations were 14.4 and 11.2 months for sacituzumab govitecan and chemotherapy, respectively, and equated to a 21% reduction in the risk for death with the use of the antibody–drug conjugate.
The 543 trial participants had received prior treatment with two to four chemotherapy regimens (median, three) in the unresectable locally advanced or metastatic disease setting, and at least one endocrine therapy, taxane, and CDK4/6 inhibitor in any setting.
Given the significant OS findings, the hierarchical statistical testing plan of the trial allowed for the assessment of objective response rate, which was significantly higher in the sacituzumab govitecan than chemotherapy group, at 21% versus 14% (odds ratio=1.63). The median durations of response were 8.1 and 5.6 months, respectively.
Sacituzumab govitecan treatment was also associated with significant improvements in certain patient-reported quality of life measures. For instance, the median time to deterioration of the EORTC QLQ-C30D global health and fatigue scores was significantly longer with sacituzumab govitecan than chemotherapy, at 4.3 versus 3.0 months and 2.2 versus 1.4 months, respectively.
By contrast, the time to deterioration of pain scores was comparable between treatments, at respective medians of 3.8 and 3.5 months for sacituzumab govitecan and chemotherapy.
Rugo added that “overall, the safety profile of sacituzumab was consistent with that observed in previous studies and no new safety signals have emerged with longer follow-up.”
And she concluded: “The statistically significant and clinically meaningful benefit of sacituzumab over [treatment of physician’s choice] in the TROPiCS-02 study supports the use sacituzumab as a novel therapy for patients with pretreated, endocrine-resistant, [HR+, HER2–] metastatic breast cancer.”
Discussant Meritxell Bellet Ezquerra (Vall d'Hebron Institute of Oncology, Barcelona, Spain) said that TROPiCS-02 is the “largest late-line trial” in this specific population and “addresses a real unmet medical need.”
She added that the findings are “clinically meaningful and should lead to regulatory approval.”
Noting the “practice-changing results” of the DESTINY-Breast04 trial of trastuzumab deruxtecan in previously treated patients with HER2-low disease, the majority of whom were HR+, the discussant wondered about the optimal sequencing of the agents.
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