A phase II trial of cabozantinib in hormone-receptor positive breast cancer with bone metastases.

CONCLUSION: Bone scans improved in 38% of patients with metastatic hormone receptor positive breast cancer and remained stable in an additional 12% for a minimum duration of 12 weeks on cabozantinib. Further investigations should assess the activity of cabozantinib in combination with other hormonal and other breast cancer therapies and determine whether bone scan responses correlate with meaningful antitumor effects. IMPLICATION FOR PRACTICE: Most patients with metastatic hormone receptor positive (HR+) breast cancer have bone involvement, and many have bone-only disease which is difficult to evaluate for response. In this phase II single arm study, we evaluated the clinical activity of the small molecule MET/RET/VEGR2 inhibitor cabozantinib in patients with metastatic HR+ breast cancer with bone metastases. This study met its primary endpoint and cabozantinib treatment resulted in a significant bone scan response rate correlating with improved survival. This is the first study to use bone scan response as a primary endpoint in breast cancer. Our results support further study of cabozantinib in HR+ breast cancer. PMID: 32463152 [PubMed - as supplied by publisher]
Source: The Oncologist - Category: Cancer & Oncology Authors: Tags: Oncologist Source Type: research