Erschienen in:
20.09.2019 | Clinical trial
A phase II study of cabozantinib alone or in combination with trastuzumab in breast cancer patients with brain metastases
verfasst von:
José Pablo Leone, Dan G. Duda, Jiani Hu, William T. Barry, Lorenzo Trippa, Elizabeth R. Gerstner, Rakesh K. Jain, Sally Tan, Elizabeth Lawler, Eric P. Winer, Nancy U. Lin, Sara M. Tolaney
Erschienen in:
Breast Cancer Research and Treatment
|
Ausgabe 1/2020
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Abstract
Purpose
To analyze the efficacy and tolerability of cabozantinib—a small molecule inhibitor of MET and VEGFR2—alone or with trastuzumab in patients with breast cancer brain metastases (BCBM).
Methods
This single-arm phase II study enrolled patients with new or progressive measurable BCBM into 3 cohorts: Cohort 1 (HER2-positive), Cohort 2 (hormone receptor-positive/HER2-negative), and Cohort 3 (triple-negative). Patients received cabozantinib 60-mg daily on a 21-day cycle. Cohort 1 added trastuzumab every 3 weeks and had a primary objective of central nervous system (CNS) objective response rate (ORR) by RECIST 1.1. Secondary objectives for all cohorts were progression-free survival, overall survival, toxicity, and changes in vascular parameters and circulating biomarkers. Cohorts 2 and 3 also had CNS ORR as a secondary objective.
Results
Thirty-six BCBM patients enrolled (cohort 1, n = 21; cohort 2, n = 7; cohort 3, n = 8), with a median age of 50. Patients had a median of 3 prior lines for metastatic disease (range 1–9). Treatments prior to enrollment included craniotomy (n = 4), whole brain radiation (n = 24) and stereotactic radiosurgery (n = 11). CNS ORR was 5% in cohort 1, 14% in cohort 2, and 0% in cohort 3. Most common grade 3/4 adverse events included elevations in lipase (11%), AST (8%), ALT (6%), hyponatremia (8%), and hypertension (6%). Cabozantinib increased plasma concentrations of CA-IX, soluble (s)MET, PlGF, sTIE-2, VEGF, and VEGF-D, and decreased sVEGFR2 and TNF-α and total tumor blood volume.
Conclusions
Cabozantinib had insufficient activity in heavily pretreated BCBM patients. Biomarker analysis showed that cabozantinib had antiangiogenic activity and increased tissue hypoxia.
Trial registration
Clinicaltrial.gov registration: NCT02260531.