Is the Breast Cancer Vaccine a Real Thing?
“As an oncologist, my dream is to be out of a job,” says Dr. Allison Close, of Michigan’s Helen DeVos Children's Hospital Hematology and Oncology. “The more discoveries that can help to prevent cancer from ever forming, the better.”
While we’re making improvements every day in early detection and management of cancers, what we really need is a way to prevent them from developing in the first place. Especially the hardest-to-treat cancers. Recent headlines have announced an imminent breast cancer vaccine. What does a breast cancer vaccine mean, exactly? Who will get it? When will it be ready?
Using a vaccine to prevent cancer isn’t unprecedented. We have been seeing declining rates of cervical cancer since the HPV vaccine became widely available (Human papillomavirus is the sexually transmitted virus known to cause many cervical cancers). The more we’re able to discover what causes cancers, the more we can intervene before they proliferate and devastate the body.
Cleveland Clinic and the University of Washington in Seattle are both in the midst of vaccine trials to prevent triple-negative breast cancer. “Triple-negative” means that the cancer cells lack receptors for estrogen or progesterone and the patient does not have normal HER2 (human epidermal growth factor receptor 2) expression. Therefore, many of our effective, targeted cancer treatments cannot be used on these cancers, making them especially aggressive and deadly. The vaccines are being evaluated both as primary prevention for those at high risk and for recurrence prevention for those who have already been treated for triple-negative cancer.
Although these cancers only account for 12-15% of all breast cancers, Black women are twice as likely to have a triple-negative cancer. For those patients with genetic predisposition like BRCA1, their tumors have a 70-80% chance of being triple-negative cancers. This means that in order to combat the staggering breast cancer mortality rate in Black women, and to fully take advantage of the insights we’re getting by doing genetic testing, a triple-negative vaccine would be revolutionary in saving breasts and lives.
“Nothing prepares you for getting a diagnosis of a cancer predisposition syndrome,” says Dr. Close. “It can be a scary and lonely world trying to make these life changing decisions - should I undergo an invasive surgery, or should I do screening? Should I have children? How do I tell my family? For me, as both a pediatric oncologist and as a person with a cancer predisposition syndrome, the idea of having a vaccine that could prevent against triple negative breast cancer is so exciting. I’ll be looking forward to hearing the results of these studies, because if successful, this could go a long way in helping entire families with cancer predisposition syndromes live a “more normal” normal.”
“Triple-negative breast cancer is the form of the disease for which we have the least effective treatments,” said G. Thomas Budd, M.D., of Cleveland Clinic’s Taussig Cancer Institute and principal investigator of the study. “Long term, we are hoping that this can be a true preventive vaccine that would be administered to cancer-free individuals to prevent them from developing this highly aggressive disease.”
The way the Cleveland Clinic vaccine works is by targeting a lactation protein, α-lactalbumin. This protein should not be present in breast cells that are no longer lactating but is found in the majority of triple-negative breast cancers. The objective of the vaccine is to prompt the immune system to attack the tumor cells and keep them from growing. Preclinical research started over a decade ago by the late Dr. Vincent Tuohy (1948-2023), who was the Mort and Iris November Distinguished Chair in Innovative Breast Cancer Research at Cleveland Clinic’s Lerner Research Institute. Early mice studies found the vaccine safe and effective in preventing tumors.
For phase 1a of the trial, participants were those who had completed treatment for early-stage triple-negative breast cancer within the past three years and are currently tumor-free but at high risk for recurrence. Phase 1a opened in 2021 and they hope to complete it by the fourth quarter of this year. They are now initiating phase 1b of the trial at the main campus of Cleveland Clinic. This cohort is cancer-free patients with high genetic/familial risk who have voluntarily undergone prophylactic mastectomies to lower their probability of developing cancer. In this phase, a small number of patients (6-12) are given three vaccinations, each two weeks apart. In Phase 1b, they are monitoring for safety and immune response. They hope to have this phase complete by the end of 2023.
The vaccine developed by Dr. Nora Disis of UW's Cancer Vaccine Institute, at the Carbone Cancer Center of the University of Washington in Seattle has already passed phase 1 and is in in phase 2 trials. The vaccine aims to activate an immune response to the HER2 protein in order to prevent recurrence of triple-negative cancer. Participants receive an initial series of three injections over the course of three months, then a booster three months after that and a final booster six months later. The trial will expand to more participants as it goes, across UW Carbone, Johns Hopkins University, and the University of Washington School of Medicine.
“We’re testing this vaccine to determine whether the patient’s immune system revs up to fight cancer cells, whether the cancer cells are there or not in patients with a previously treated triple-negative cancer,” says Dr. Lee Wilke, senior medical director of Clinical Oncology Services, UW Health, and principal investigator for the clinical trial at UW Carbone.
In late 2022, the researchers published data from a Phase I safety trial of their vaccine. Gizmodo.com explains that the study included sixty-six women with advanced stage breast cancer who had “undergone treatment that either put their cancer into complete remission or largely contained it, but they remained at high risk of it aggressively reemerging. The volunteers were tracked for a median length of about 10 years.” Insider adds, “Eighty percent of women who got the vaccine have survived the ten-year study period, which is well above the expected 50% five-year survival rate for their type of cancer.”
How soon can we expect the vaccine to be available?
“Each novel vaccine candidate needs to be evaluated for safety, immunogenicity, and protective efficacy in humans before it is licensed for use,” reminds the NIH. According to Johns Hopkins University, the “typical vaccine development timeline takes five to ten years, and sometimes longer” as evaluation of safety and efficacy is done on increasingly large patient population at each phase. The regulation approval process, manufacturing and distribution take time, as well.
Researchers of the breast cancer vaccine are optimistic. Dr. Nora Disis said that she expects to see a therapeutic cancer vaccine available to patients within the next five years. Not only that, but the UW team is also testing several other breast cancer vaccine possibilities, as well as developing vaccines that will prevent colon ovarian, lung, bladder, and prostate cancers.
We’re getting better and better at treating these devastating cancers, but this gives us hope that one day, hopefully soon, we can eliminate them altogether.
Sarah Zimmerman is a freelance writer in Northern California and is working on her first novel. In past lives,, she has been a Physician Assistant in Women's Health and the owner of a vegan ice cream business. Sarah writes about marriage, sex, parenting, infertility, pregnancy loss, social justice, and women's mental and physical health, always with honesty and humor. She has written for Ravishly, Cafe Mom, Pregnant Chicken, and more and can be found at sarahzwriter.com and on Medium, Twitter, Facebook, Instagram and TikTok at @sarahzwriter.