Hope S Rugo1, Aditya Bardia2, Frederik Marmé3, Javier Cortes4,5, Peter Schmid6, Delphine Loirat7, Olivier Trédan8, Eva Ciruelos9, Florence Dalenc10, Patricia Gómez Pardo11, Komal L Jhaveri12, Rosemary Delaney13, Olivia Fu14, Lanjia Lin15, Wendy Verret13, Sara M Tolaney16. 1. Department of Medicine, University of California San Francisco Helen Diller Family Comprehensive Cancer Center, San Francisco, CA. 2. Medical Oncology, Massachusetts General Hospital Cancer Center, Harvard Medical School, Boston, MA. 3. Medical Faculty Mannheim, Heidelberg University, University Hospital Mannheim, Heidelberg, Germany. 4. Medical Oncology Department, International Breast Cancer Center, Pangaea Oncology, Quironsalud Group, Madrid and Barcelona, Spain. 5. Faculty of Biomedical and Health Sciences, Department of Medicine, Universidad Europea de Madrid, Madrid, Spain. 6. Barts Cancer Institute, Queen Mary University of London, London, United Kingdom. 7. Medical Oncology Department and D3i, Institut Curie, Paris, France. 8. Medical Oncology Department, Centre Léon Bérard, Lyon, France. 9. Medical Oncology, Hospital Universitario 12 de Octubre, Madrid, Spain. 10. Institut Claudius Regaud, IUCT-Oncopole, Toulouse, France. 11. Hospital Universitari Vall D'Hebron, Barcelona, Spain. 12. Memorial Sloan-Kettering Cancer Center, New York, NY. 13. Department of Clinical Development, Gilead Sciences Inc, Foster City, CA. 14. Department of Global Patient Safety, Gilead Sciences Inc, Foster City, CA. 15. Department of Biostatistics, Gilead Sciences Inc, Foster City, CA. 16. Department of Medical Oncology, Dana-Farber Cancer Institute, Boston, MA.
Abstract
PURPOSE: Hormone receptor-positive (HR+) human epidermal growth factor receptor 2-negative (HER2-) endocrine-resistant metastatic breast cancer is treated with sequential single-agent chemotherapy with poor outcomes. Sacituzumab govitecan (SG) is a first-in-class antibody-drug conjugate with an SN-38 payload targeting trophoblast cell-surface antigen 2, an epithelial antigen expressed in breast cancer. METHODS: In this global, randomized, phase III study, SG was compared with physician's choice chemotherapy (eribulin, vinorelbine, capecitabine, or gemcitabine) in endocrine-resistant, chemotherapy-treated HR+/HER2- locally recurrent inoperable or metastatic breast cancer. The primary end point was progression-free survival (PFS) by blinded independent central review. RESULTS: Patients were randomly assigned to receive SG (n = 272) or chemotherapy (n = 271). The median age was 56 years, 95% had visceral metastases, and 99% had a prior cyclin-dependent kinase 4/6 inhibitor, with three median lines of chemotherapy for advanced disease. Primary end point was met with a 34% reduction in risk of progression or death (hazard ratio, 0.66 [95% CI, 0.53 to 0.83; P = .0003]). The median PFS was 5.5 months (95% CI, 4.2 to 7.0) with SG and 4.0 months (95% CI, 3.1 to 4.4) with chemotherapy; the PFS at 6 and 12 months was 46% (95% CI, 39 to 53) v 30% (95% CI, 24 to 37) and 21% (95% CI, 15 to 28) v 7% (95% CI, 3 to 14), respectively. Median overall survival (first planned interim analysis) was not yet mature (hazard ratio, 0.84; P = .14). Key grade ≥ 3 treatment-related adverse events (SG v chemotherapy) were neutropenia (51% v 38%) and diarrhea (9% v 1%). CONCLUSION: SG demonstrated statistically significant PFS benefit over chemotherapy, with a manageable safety profile in patients with heavily pretreated, endocrine-resistant HR+/HER2- advanced breast cancer and limited treatment options.
PURPOSE: Hormone receptor-positive (HR+) human epidermal growth factor receptor 2-negative (HER2-) endocrine-resistant metastatic breast cancer is treated with sequential single-agent chemotherapy with poor outcomes. Sacituzumab govitecan (SG) is a first-in-class antibody-drug conjugate with an SN-38 payload targeting trophoblast cell-surface antigen 2, an epithelial antigen expressed in breast cancer. METHODS: In this global, randomized, phase III study, SG was compared with physician's choice chemotherapy (eribulin, vinorelbine, capecitabine, or gemcitabine) in endocrine-resistant, chemotherapy-treated HR+/HER2- locally recurrent inoperable or metastatic breast cancer. The primary end point was progression-free survival (PFS) by blinded independent central review. RESULTS: Patients were randomly assigned to receive SG (n = 272) or chemotherapy (n = 271). The median age was 56 years, 95% had visceral metastases, and 99% had a prior cyclin-dependent kinase 4/6 inhibitor, with three median lines of chemotherapy for advanced disease. Primary end point was met with a 34% reduction in risk of progression or death (hazard ratio, 0.66 [95% CI, 0.53 to 0.83; P = .0003]). The median PFS was 5.5 months (95% CI, 4.2 to 7.0) with SG and 4.0 months (95% CI, 3.1 to 4.4) with chemotherapy; the PFS at 6 and 12 months was 46% (95% CI, 39 to 53) v 30% (95% CI, 24 to 37) and 21% (95% CI, 15 to 28) v 7% (95% CI, 3 to 14), respectively. Median overall survival (first planned interim analysis) was not yet mature (hazard ratio, 0.84; P = .14). Key grade ≥ 3 treatment-related adverse events (SG v chemotherapy) were neutropenia (51% v 38%) and diarrhea (9% v 1%). CONCLUSION: SG demonstrated statistically significant PFS benefit over chemotherapy, with a manageable safety profile in patients with heavily pretreated, endocrine-resistant HR+/HER2- advanced breast cancer and limited treatment options.