The Food and Drug Administration (FDA) gave investigational new drug (IND) approval to the Mayo Clinic for two new cancer vaccines aimed at preventing cancer recurrence. The IND program gives the pharmaceutical company approval for Phase 1 clinical trials with women treated for ovarian or breast cancer.
Developed by Mayo Clinic immunologist Keith Knutson, PhD, and colleagues, the vaccines may help people who’ve had cancer and are at high risk for relapse. Knutson’s group focuses on immunizing patients immediately after therapy, when they’re healthy, to protect against a relapse. Previous cancer vaccines have been developed to fight patients’ tumors.
The two new vaccines include a HER-2/neu vaccine and a folate receptor alpha vaccine. “For both vaccines, patients will be immunized monthly for 6 months,” says Knutson. There will also be approximately two years of periodic follow-up after immunization to assess whether or not the vaccine safely generates immune memory.”
The vaccine brings to mind the cervical cancer vaccine, which creates immunity against proteins produced by the human papilloma virus (HPV), the causative agent behind most cervical cancers. “These new vaccines differ in several ways,” says Knutson. He explains that all are designed to generate immune responses to proteins. Immunity against HPV proteins prevents HPV infection, secondarily also preventing cervical cancer development, explains Knutson. “In contrast, our vaccines generate immunity against proteins which are not from a virus but which are present at low levels naturally in the body but are present at high levels in the cancers.”
Knutson’s research shows that the immune system can tell which cells produce high levels of the proteins (for example, the cancer cells) as opposed to those noncancerous that produce limited amounts of the protein. The protein is typical of most breast and ovarian tumors, which may make the vaccine potentially helpful for a majority of patients, instead of those populations with certain types of cancer.
“The folate receptor alpha vaccine is unique in that it incorporates a new strategy that we are testing to greatly ‘boost’ the immune responses generated following vaccination,” says Knutson. Just prior to receiving the vaccine, patients will be given a single dose of a drug called Ontak, which suppresses the body’s natural mechanisms that tend to limit immune responses. The second vaccine is administered after chemotherapy and targets the highly aggressive Her2/neu molecule, a protein that promotes the growth of cancer cells.
Ultimately, the vaccine may be useful as a preventive strategy for all women, says Knutson.
CONNECT THE DOTS
For further information on breast cancer risk factors go to the U.S. National Library of Medicine or the National Cancer Institute website. For information on vaccines in general and for the HPV vaccine go to the Centers for Disease Control and Prevention.
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