For years, the holy grail of breast cancer research has been a vaccine that prevents the disease. Considerable progress has been made, thanks in part to Susan G. Komen® and St. Louis scientists.
In 2011, Komen awarded a $6.5 million Promise Grant to Washington University School of Medicine researchers at the Siteman Cancer Center. They’re working on vaccines aimed at both preventing the disease and preventing recurrence after treatment.
The idea behind the vaccines is to equip a person’s immune system to fight off cancerous growth, says Promise Grant co-recipient William Gillanders, MD, vice chair for research at Washington University School of Medicine’s Department of Surgery.
“In the last decade we’ve made a huge amount of progress towards that goal,” he says. “We have a much better understanding of the immune system, how and why vaccines work and when it would be most appropriate to use them.”
Gillanders’ fellow Promise Grant recipients are Ted Hansen, PhD, a professor of pathology and immunology and of genetics, and Elaine Mardis, co-director of The Genome Institute and professor of genetics.
A prevention vaccine could be a decade or more away, Gillanders said. Meanwhile, a clinical trial has begun on a vaccine that would prevent recurrence in patients who have been treated.
The vaccine targets mammaglobin-A, a protein initially discovered at Washington University and found in 80 percent of breast tumors. Called a Phase I clinical trial, it is meant to determine if the treatment is safe; however, researchers are measuring patients’ immune response to the vaccine.
“None of the them have had significant toxicities to date,” Gillanders says. “We’ve been able to detect evidence of an immune response. We would like to move now to a Phase II clinical trial, where we can have a more rigorous evaluation of the biologic response.”
Many patients with breast cancer receive endocrine therapy before surgery, typically for about four months, to shrink tumors and to make surgery safer and more effective. Gillanders hopes that one day the anti-recurrence vaccine may be given at this time, as well.
Another vaccine in development involves genome sequencing. That is, decoding the DNA of patients and identifying the differences between normal cells and cancer cells. After sequencing the cells, researchers would design a personalized vaccine for each patient using her own immune system to destroy the cancer cells, either to treat an existing tumor or to prevent recurrence. The patient would receive the vaccination after surgery, chemotherapy and radiation therapy.
Eventually, a woman who is identified as being at high risk for developing breast cancer could be a potential vaccine candidate too. That could be 10 years away, but it’s what the team is striving for.
“We’re not quite there yet, but certainly cancer prevention is one of the long-term goals of developing a vaccine,” Gillanders says.