Cabozantinib for metastatic breast carcinoma: results of a phase II placebo-controlled randomized discontinuation

Sara M Tolaney1,2, Hovav Nechushtan3, Ilan-Gil Ron4

  • 1Department of Medical Oncology, Breast Oncology Center, Dana-Farber Cancer Institute, 450 Brookline Avenue, Boston, MA, 02215, USA. stolaney@partners.org.

Abstract

Insights

Cabozantinib showed clinical activity in heavily pretreated metastatic breast cancer (MBC) patients, demonstrating objective response and disease control. Further investigation into cabozantinib monotherapy for MBC is warranted.

Area of Science:

  • Oncology
  • Pharmacology

Background:

  • Metastatic breast cancer (MBC) remains a significant clinical challenge, necessitating novel therapeutic strategies.
  • Cabozantinib is an oral multi-targeted tyrosine kinase inhibitor (TKI) with demonstrated activity against key oncogenic pathways, including MET, VEGFR2, and AXL.

Purpose of the Study:

  • To evaluate the efficacy and safety of cabozantinib in patients with metastatic breast cancer (MBC).
  • To assess objective response rate (ORR) and progression-free survival (PFS) in a phase II randomized discontinuation trial (RDT).

Main Methods:

  • A phase II RDT was conducted involving heavily pretreated MBC patients.
  • Patients received a 12-week lead-in of 100 mg daily cabozantinib.
  • Patients with stable disease were randomized to continue cabozantinib or receive placebo; however, randomization was suspended.

Main Results:

  • The ORR during the lead-in stage was 13.6%, with a disease control rate of 46.7% at 12 weeks.
  • Median PFS for all MBC patients was 4.3 months, and median overall survival (OS) was 11.4 months.
  • Common grade 3/4 adverse events included palmar-plantar erythrodysesthesia and fatigue; one drug-related death occurred.

Conclusions:

  • Cabozantinib monotherapy demonstrated clinical activity in heavily pretreated MBC patients.
  • The study supports the potential of cabozantinib as a treatment option for MBC.
  • Further research is warranted to optimize its use in this patient population.