New Drug Can Shrink Cancer Tumors Better

Each year 45,000 women die from breast cancer. Doctors say that the reason many of these women die is from metastatic cancer.

Metastatic breast cancer is when the cancer returns in other organs of the body.

Many advances have been made over the last few years including better methods of detection, better surgical procedures to manage patients with newly diagnosed cancer, and new treatments to prevent breast cancer recurrence.

Yet doctors say about 25 percent to 30 percent of patients eventually have their cancer return. Patients with metastatic breast cancer survive, on average, just three years.

This is why researchers say it's critical they find new drugs and treatments for these women.

Eight medical institutions around the world are studying a new investigational treatment for metastatic breast cancer.

The Phase II clinical trial of an epothilone analog, BMS-247550, is designed to test the effectiveness of administering the drug as a one-hour intravenous infusion every three weeks.

Doctors called the drug epothilone B for short.

"This is an example of a new treatment approach to breast cancer," said Dr. Edith Perez from Mayo Clinic.

"It's developed as a result of improved understanding of the molecular basis of this disease. We hope that the novel mechanism action of this agent will translate into improved outcomes for women with breast cancer," she added.

Currently, one of the most effective treatments for metastatic breast cancer is a class of drugs called taxanes, which include paclitaxel and docetaxel. However, doctors say many patients eventually develop a resistance to the taxane drugs. This allows the regrowth of the cancer.

The new drug, epothilone B, interferes with the process of cell division, as do taxanes, yet in early trials, the drug demonstrated effectiveness against cancer cells insensitive or resistant to paclitaxel.

While doctors are enthusiastic about these results, they caution that the trials are still in their early stages. The drug is not FDA approved and is only available to women who take part in a clinical trial.

The drug is given to the patient intravenously.

Doctors said that they are still working on the dosing levels of this drug because of reports of some severe side effects.

The main side effect is peripheral neuropathy. Peripheral neuropathy is numbness and tingling in the patient's fingers and toes.

Doctors said at the beginning the patients seem to do well, but as they are on the drug for longer periods of time the peripheral neuropathy starts to develop.

Patients also may experience hair loss.

"Over the last few months, we've changed the dose of this medication and we think this change will allow for better tolerability," Perez said.

More information on the clinical trials on epothilone B is expected later this year.

For more information, contact:
Erik Kaldor
Mayo Clinic
4500 San Pablo
Jacksonville, FL 32224
(904) 953-2299