A preventive breast cancer vaccine developed by Professor Vincent Tuohy of the Cleveland Clinic will be brought forward to the FDA for permission to begin clinical trials to see if it is safe and effective for use in women.
The vaccine was shown to be completely safe and 100% effective in preventing breast cancer in three animal models, (see study in Nature Medicine), and was also found to slow the growth of tumors that had already formed. The vaccine is especially powerful in inhibiting the growth of triple-negative breast cancer, the most aggressive form of the disease with the lowest survival rate.
Triple-negative breast cancer lacks estrogen, progesterone and Her2 receptors. It occurs in approximately 15% of cases is the kind of breast cancer most common in women who carry a BRCA mutation.
The initial clinical trials, called Phase I studies, will be conducted in two groups of volunteers, women with triple-negative breast cancer who have completed their treatment and are free of disease, and women who will be vaccinated shortly before undergoing bilateral prophylactic mastectomy (typically these are women like Angelina Jolie with BRCA mutations who elect to remove their breasts to lower their risk for cancer.)
The first group of women will be studied to determine the dose and effectiveness of the vaccine; the second will be studied to make sure the vaccine does not trigger an untoward immune response in breast tissue.
The vaccine targets an unique protein normally made only by women who are breastfeeding, alpha lactalbumin (ALA). In the 12 years Tuohy spent developing and researching his vaccine, he discovered that the majority of breast tumors express, or make, ALA. Priming the immune system with a vaccine so that it attacks any cell that makes ALA is the method by which Tuohy’s vaccine works.
Because the vaccine targets ALA, a protein necessary for successful lactation in healthy women, the vaccine would not be appropriate for use in women who are still in their childbearing years.
However, the majority of women diagnosed with breast cancer in the United States and other western countries are post-menopausal: at least 60% of the cases in the United States occur in women over 55; thus, Tuohy’s vaccine holds great potential as a preventive vaccine for the majority of women.
Because the vaccine has also demonstrated therapeutic potential (in slowing the growth of tumors that have already formed), it may also prove useful in treating women who already have the disease, particularly women with triple-negative breast cancer for which there are presently no available targeted therapies.
Other scientists have joined the movement toward creating preventive as well as therapeutic vaccines. Dr. Brian Czerniecki of the University of Pennsylvania has a very effective vaccine to treat women with ductal carcinoma in-situ whose tumors express the growth receptor, Her2. And just recently, Dr. Susan Love and the National Breast Cancer Coalition began working with a panel of scientists on the Artemis Project, whose goal is to end all breast cancer in seven years, hopefully by way of a vaccine.
However, only Tuohy’s preventive breast cancer vaccine and Dr. Czerniecki therapeutic breast cancer vaccine have reached bench-to-bedside potential to begin clinical trials in human subjects.
While it’s true that not everything that works in mice works in women, everything that currently works in women first worked in mice. Since so much is at stake – millions of lives, millions of breasts, billions of dollars – the possibility of developing an effective preventive breast cancer vaccine has captured the imagination of scientists, the financial commitment of institutions like the Cleveland Clinic, and broad support from a groundswell of women who would prefer prevention to the rigors of a cure. The Pure Cure for breast cancer, prevention, is now the mission.
Fast-tracking Tuohy’s vaccine through the FDA so that clinical trials can begin as soon as possible is the present objective – to see if it’s safe and, if safe, to see if it works. Opinions may vary about its potential – they always do – but, fortunately, clinical trials are the arena in which final scientific arbitration takes place, and they are now on the road with regard to this vaccine.
The gruesome data on the global burden of breast cancer remains vivid: In 2013 alone, 1.5 million new cases – one every 20 seconds – and 500,000 deaths – one every minute. And provide the most compelling arithmetic for moving forward, reasonably but quickly. Let the vaccine speak for itself. Put it to the test and “let slip the dogs of war” to prevent breast cancer if we can, as soon as we can.
Kathleen T. Ruddy, MD is a breast cancer surgeon and Founder and President of the Breast Health and Healing Foundation.