Experimental Drug Shows Promise for Certain Breast Cancers

An experimental drug designed to treat patients with a specific kind of breast cancer known as HER2-positive appeared to boost survival compared to the standard treatment, a new study shows.

The drug, known as trastuzumab emtansine (T-DM1), is in the final stage of research necessary before the U.S. Food and Drug Administration can approve its sale. For now, it is only available in clinical trials.

"The drug worked. It was significantly better than a very effective approved therapy for HER2-overexpressing metastatic breast cancer," study author Dr. Kimberly Blackwell, a professor of medicine and an assistant professor of radiation oncology at Duke Cancer Institute in Durham, N.C., said in a news release from the American Society of Clinical Oncology.

"Also, as a clinician who takes care of a lot of breast cancer patients, I'm pleased that this drug has very little dose-limiting toxicity," she added. "Patients don't lose their hair from this drug. For patients facing metastatic breast cancer, this is a breakthrough."

Patients with HER2-positive breast cancer have a protein called human epidermal growth factor receptor 2 that promotes cancer cell growth.

Promise for Certain Breast Cancers Moving a basic scientific finding from a lab to the clinical setting is the Holy Grail for medical researchers the world over. Suzanne Conzen, MD, professor of hematology/oncology at the University of Chicago, is expediting that process with a rare investigator-initiated Phase I clinical trial for a novel approach to breast cancer therapy that she discovered.

The therapy targets a subtype of breast cancer that currently has no specific therapy regimen and is characterized by early relapses: so-called "estrogen receptor-negative" breast cancer, which involves a tumor that is not fueled by estrogen. That includes about 25 to 30 percent of the 230,000 women diagnosed with breast cancer every year.

Conzen is able to expedite the bench-to-bedside process because the therapy she is testing uses a pharmaceutical agent that is already approved for clinical indications in humans.

"Due to her industry ties as well as her excellent reputation as a researcher and clinician, Dr. Conzen was able to secure the drug and placebo at no cost from the manufacturer," says Heather Walsh, project manager at UChicagoTech, the University of Chicago’s Office of Technology and Intellectual Property.

Conzen and Rita Nanda, MD, an assistant professor of hematology/oncology at the University, wrote a clinical trial protocol that has been approved by the Food and Drug Administration and the University’s Institutional Review Board. Support for research nursing during the trial is being provided by the University of Chicago’s Comprehensive Cancer Center using National Institutes of Health (NIH) funds. An NIH-funded Clinical and Translational Science Award is providing additional support for Conzen and Nanda to analyze enrolled patient samples to address key scientific questions during the trial.