The study was presented in poster form on December 9^th by Tiffany Traina, MD, fellow in oncology, department of medicine, Memorial Sloan-Kettering Cancer Center, New York.

A total of 28 patients, mean age 49 years, received letrozole 2.5 mg/day and bevacizumab 15 mg/kg bodyweight by IV injection every 3 weeks. All were postmenopausal and all were estrogen receptor-positive. Half had received prior tamoxifen therapy. Four of 5 were progesterone receptor-positive. More than half had lung or liver metastases, and 39% had metastasis to the bones.

Five patients were withdrawn from the study, 3 because of adverse events, and 2 who withdrew their consent.

Hyperglycemia was the most common adverse event, occurring in 25% of patients. Hypertension, fatigue, and joint pain each occurred in 14% of patients.

Of the 23 patients who were still available for efficacy evaluation, 5 were not on therapy for a long enough duration of time for their results to be recorded.

Of the 18 who were evaluated for efficacy, 57% had stable disease, meaning there was no progression for at least 24 weeks. The median duration of progression-free survival from the time the patients received their first dose of bevacizumab was 6 months. A partial response was seen in 9% of patients and there were no complete responses recorded. Progressive disease occurred in 13% of patients.

An important finding from the study was that circulating epithelial cells (CEC) -- a marker for angiogeneic activity -- could be used to predict progression-free survival. After as little as 12 weeks of therapy, an increase in CEC could be correlated with a worse prognosis, while a decrease in CEC was predictive of a longer progression-free survival time.

Dr. Traina concluded in her poster that these preliminary efficacy results were "encouraging" and that further study using this regimen is warranted. Furthermore, CECs may be an important predictive marker and these too should be evaluated further in future studies, she said.

The combination f bevacizumab and letrozole was well tolerated, with adverse effects that were anticipated and were not severe in most cases, she concluded.


[Presentation title: A Phase II Trial of Letrozole in Combination With Bevacizumab, an Anti-VEGF Antibody, in Patients With Hormone Receptor-Positive Metastatic Breast Cancer. Abstract 2030]

Copyright © 2009 P\S\L Consulting Group Inc. All rights reserved. Republication or redistribution of P\S\L content is expressly prohibited without the prior written consent of P\S\L. P\S\L shall not be liable for any errors, omissions or delays in this content or any other content on its sites, newsletters or other publications, nor for any decisions or actions taken in reliance on such content.