Rochester Mayo Clinic approved for cancer vaccine trial

The Mayo Clinic in Rochester has received approval to administer ovarian and breast cancer vaccines as a clinical trial.

Approval from Food and Drug Administration clears the way for Phase I clinical trials with women who are being treated for ovarian or breast cancer, said Mayo Clinic immunologist Keith Knutson.

The vaccines are among the first aimed at preventing cancer recurrence. They work by mobilizing the body's defense mechanisms to destroy malignant cells. Pre-clinical studies show the immune system can be stimulated to prevent and eliminate cancers from the body, Knutson said. The group is optimistic about the trial's potential.

"We think it's a major step forward in terms of being able to test and hopefully move to approval of vaccines that we can give to patients," Knutson said.

One of the vaccines targets a protein that exists in abundance in breast and ovarian cancer cells. It teaches the body's immune system to detect and eliminate diseased cells.

The second vaccine is designed to be administered after breast cancer patients receive conventional chemotherapy. It targets a highly aggressive molecule that promotes the growth of cancer cells.

Trials will include up to 25 women for each vaccine and are expected to begin by the end of the year. Vaccines will be administered monthly into the skin over a six-month period.