ROCHESTER, Minn. – Z-endoxifen, a potent derivative of the drug tamoxifen, could itself be a new treatment for the most common form of breast cancer in women with metastatic disease. This finding was reported from a clinical trial conducted by researchers at Mayo Clinic and the National Cancer Institute, and published in the Journal of Clinical Oncology.
The final results of a first-in-human phase I study of Z-endoxifen in women with estrogen receptor positive metastatic breast cancer showed that the treatment was safe and resulted in tumor shrinkage in women whose tumors had progressed on standard anti-estrogen therapies, including tamoxifen.
Journalists: Broadcast-quality video of Dr. Goetz’s comments is available in the downloads. Read a transcript.
“Tamoxifen, is converted into endoxifen in the liver by an enzyme called CYP2D6. Our previous research found that tamoxifen may be less effective in women with poor CYP2D6 metabolism,” says Matthew Goetz, M.D., the study’s lead author and an oncologist at Mayo Clinic.
Based on laboratory studies showing that endoxifen better inhibits tumor growth compared to tamoxifen, Dr. Goetz and his colleagues partnered with researchers at the National Cancer Institute to develop Z-endoxifen, an…