About 1 in 8 women will develop invasive breast cancer in her lifetime, and some will be diagnosed with one of the most deadly forms of the disease: triple-negative breast cancer, which has the least effective treatments. Yet researchers at Cleveland Clinic hope to change that: They've launched a phase 1 clinical trial for a vaccine to hopefully help prevent this aggressive form of the disease, though it will likely take decades to come to fruition, if all goes well.
The new study includes a small group of women, who are not lactating and will not become pregnant, who have recently completed treatment for early-stage triple-negative breast cancer. These patients do not have any signs of disease, but remain at high risk of recurrence.
How does this experimental breast cancer vaccine work?
The vaccine will target a protein, alpha-lactalbumin, which is usually made in lactating breasts. There is no other time when normal human cells make that protein, except some 70% of triple-negative breast cancers make the protein, according to Dr. G. Thomas Budd, an oncologist at the Cleveland Clinic and principal investigator of the study.
"What we hope to do is, first, show that we can mount an immune response against one protein that is expressed in the majority of triple-negative breast cancer," said Budd. "And if we can, we might be able to vaccinate patients or people who are at risk to develop breast cancer, and then prevent them from getting it in the first place — that's the long-term goal."
The 18-24 people in the trial will receive varying doses of the vaccine to determine the side effects and whether it produces the desired immunologic response. They'll receive three vaccinations, two weeks apart. The goal of the phase 1 study is determine what dose should be used in further studies, based on side effects and the immune response.
"The ultimate goal, ultimately, not of this trial, but future trials, would be to be able to prevent breast cancer, triple-negative breast cancer in those who are at very high risk for it," said Budd. "So, initially this would be people with family histories and genetic mutations known to predispose them to triple-negative breast cancer."
“This vaccine approach represents a potential new way to control breast cancer,” said Vincent Tuohy, the primary inventor of the vaccine and staff immunologist at Cleveland Clinic’s Lerner Research Institute, in a press release. “The long-term objective of this research is to determine if this vaccine can prevent breast cancer before it occurs, particularly the more aggressive forms of this disease that predominate in high-risk women.”
The bottom line:
According to the American Cancer Society, triple-negative breast cancer accounts for about 10%-15% of all breast cancers, but is more common in women under 40, Black women and women who have the BRCA1 mutation.
"I think the main thing I do want to just emphasize is this is very, very early in development," stressed Budd. "It will take really decades to prove what we need to prove because it takes years to develop breast cancer, but you know it's the first step."