Mayo Clinic Receives FDA Approval on Breast Cancer Drug Trials

Mayo Clinic has received approval from the Food and Drug Administration to test two vaccines against cancer.The drugs are designed to prevent recurrence of ovarian and breast cancer and "mobilize the body's defense mechanisms to destroy malignant cells," according to Mayo.The vaccines are among the first aimed at preventing cancer recurrence and mean Mayo researchers will be allowed to undertake Phase I clinical trials in women who have already been treated for cancer. This early-phase study will check to see if the vaccines can be given to patients safely after cancer treatment, said researcher Keith Knutson, who developed the vaccine at Mayo with a team of colleagues.

According to Mayo's announcement, one vaccine targets a protein abundant in both breast and ovarian cancer cells.The vaccine teaches the body's immune system to detect and eliminate diseased cells, Mayo Clinic says. Because the protein is typical of nearly all breast and ovarian tumors, the vaccine is the first that might be applicable to most patients instead of only sub-populations with distinct types of cancer, researchers believe.The second vaccine will be given to study participants after the patients get standard chemotherapy.Knutson cautions that the development of any drug is a multi-stage process. FDA "investigational" approval means the clinic had sufficient evidence to show the vaccine merits human testing, he said in an interview.About 25 women will be included in the first group of study participants, Knutson said. Researchers will watch for side effects of the vaccine and also want to make sure that the patients exhibit an immune response, necessary for an effective vaccine.

If Phase 1 is successful, researchers will move to a Phase 2, double-blind study, to determine whether the vaccine prevents cancer recurrence.Knutson said animal models at Mayo have been successful. Researchers need to show the same in humans, though, because the effect on mice is not necessarily transferable to humans.Phase 1 results are likely to be published in 2014, Knutson said. Researchers will be alerted before then if side effects appear. Knutson expects the first 25 patients to be immunized between the end of 2011 and the end of 2013.