Sorafenib Plus Chemotherapy Significantly Prolongs Progression-Free Survival in Advanced Breast Cancer

Bayer HealthCare Pharmaceuticals and Onyx Pharmaceuticals, Inc, announced the full results from their first collaborative group-sponsored randomized, double-blind, placebo-controlled phase II trial showing that sorafenib (Nexavar) tablets in combination with the oral chemotherapeutic agent, capecitabine (Xeloda), significantly extended progression-free survival in patients with advanced breast cancer. The data were presented at the joint 15th European CanCer Organisation (ECCO) and 34th European Society for Medical Oncology (ESMO) Multidisciplinary Congress in Berlin.

74% Improvement
Jose Baselga, MD, chairman and professor of medicine at Vall d’Hebron Institute of Oncology in Barcelona, scientific chairman of the Spanish Breast Cancer Cooperative Group SOLTI and the principal investigator of this study, reported that patients receiving sorafenib plus capecitabine had a 74% improvement in the time they lived without their disease progressing compared to those who received the chemotherapy alone. The difference in median progression-free survival with sorafenib plus capecitabine vs capecitabine plus placebo was statistically significant, 6.4 vs 4.1 months (hazard ratio = 0.576, P = .0006).

“Onyx and Bayer have built a strong foundation with Nexavar in treating unresectable liver cancer and advanced kidney cancer-both disease areas with a previously unmet treatment need,” said Todd Yancey, md, vice president of clinical development at Onyx. “These new results signify another step in understanding the potential role of Nexavar in breast cancer.”

Breast Cancer Trial Design
The randomized, double-blind, placebo-controlled phase II study evaluated sorafenib in combination with capecitabine in 229 patients with locally advanced or metastatic HER2-negative breast cancer. These patients had received no more than one prior chemotherapy in this setting. The primary endpoint of the study was progression-free survival. Secondary endpoints included overall survival, time to progression, and safety. Patients were randomized to receive 400 mg of oral sorafenib or matching placebo twice daily, in addition to 1,000 mg/m² of capecitabine twice daily for 14 days followed by a 7-day rest from capecitabine.

Overall, treatment with sorafenib plus capecitabine was tolerable and resulted in no new side effects. Common grade 3 or 4 treatment-related adverse events included hand-foot skin reaction, diarrhea, dyspnea, neutropenia and mucositis.