Zoledronic Acid Disappoints for Overall Breast Cancer Survival
Zoledronic acid, a bone drug used to prevent skeletal complications during cancer treatment, has not been shown to improve survival time for younger pre-menopausal women with breast cancer. The drug, marketed as Zometa did show significant survival benefit in a subset of post-menopausal women.
Zometa Improves Breast Cancer Survival for Menopausal Women
Though the Phase III AZURE trial for zoledronic acid was disappointing, the drug findings were different for older menopausal women. Women five years past menopause had a 27 percent reduced risk of breast cancer recurrence compared to a control group receiving standard therapy. Deaths from cancer were reduced 29 percent.
Robert E. Coleman, MD, of the academic unit of clinical oncology at Weston Park Hospital in Sheffield, UK, Sharon said in a press statement, "To see a survival advantage like this is quite remarkable, and the difference in outcome between this group and the younger population is unlikely to be a chance finding. We will clearly want to investigate further in this population.”
Hervé Hoppenot, President, Novartis Oncology says, "These trial results do not impact the current usage of Zometa, which continues to be a critical treatment for many patients with a broad range of metastatic cancers and multiple myeloma. Although we did not see an overall disease free survival advantage for early breast cancer patients receiving Zometa in the adjuvant setting, we're encouraged that a subset of postmenopausal patients in the trial experienced an improvement."
The current trial focused on women with stage II and stage III breast cancer. The AZURE trial shows zoledronic acid is not useful for young women with functioning ovaries and without cancer bone metastasis.
In the 2008 Austrian Breast and Colorectal Cancer Study Group Trial 12 (ABCSG-12), zoledronic acid lowered the risk for early breast cancer recurrence 36 percent compared to women not taking the drug. Zometa is used for treatment of osteoporosis and preventing bone and spinal compression fractures in patient with cancer bone metastasis. The drug was recently shown to extend life for patients with multiple myeloma.
Novartis plans to withdraw marketing applications for treating pre-menopausal women with early stages of breast cancer with Zometa. The company says the study results have no impact on use of zoledronic acid for treating bone complications associated with cancer treatment.
The overall findings from the AZURE trial that included 3,360 women who were given chemotherapy and or hormone therapy failed to find benefit for breast cancer survival after 5 years of treatment. The study included 403 women receiving standard treatment and 404 women given chemo plus zoledronic acid.
Novartis will review findings from the AZURE trial and revamp based on the new findings that the drug has benefit for breast cancer survival among postmenopausal women.
Though the findings for extending breast cancer survival were disappointing, the subset of postmenopausal women who benefited from the drug, “could signal a new direction in research”, according to commentary from Rowan Chlebowski, MD, PhD, of the medical oncology/hematology department at the University of California at Los Angeles.