World’s first breast cancer vaccine clinical trial, officially launched
Recently, Cleveland Clinic researchers formally initiated a clinical trial of a breast cancer vaccine aimed to prevent triple-negative breast cancer, which could become the first breast cancer vaccine ever developed. The clinical trial is based on a 2010 study published in Nature Medicine.
Breast cancer, the most common cancer among women, has overtaken lung cancer as the world’s leading cause of death in 2020. According to WHO’s International Agency for Research on Cancer’s (IARC) most recent global cancer burden figures for 2020, there were up to 2.26 million new cases of breast cancer and 680,000 deaths globally in 2020.
Most breast cancers have a good prognosis, however roughly 10% to 20% of all breast cancers are triple-negative, so named because they lack the estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor-2 (HER-2). Triple-negative breast cancers are the most aggressive and fatal types of breast cancer, which are more likely to spread and metastasis, are prone to recurrence, and have been a tough part of breast cancer treatment due to a lack of therapeutic targets and therapeutic drugs.
The goal of this phase I clinical trial is to discover the maximum tolerable dose of the vaccine in patients with early-stage triple-negative breast cancer, as well as to define and optimize the immune response.
Although triple-negative breast cancers lack typical therapeutic targets, namely estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor-2 (HER-2), most triple-negative breast tumors include alpha-lactalbumin (α-lactalbumin), a breast-specific secretory milk protein.
α-lactalbumin is not present in normal and aging tissues, so activating the immune system to target α-lactalbumin could allow for a preemptive strike to inhibit triple-negative breast cancer tissues that express α-lactalbumin. In addition, the vaccine contains an adjuvant that activates the innate immune response, causing the immune system to respond to emerging tumors and inhibit their growth.
This breast cancer vaccine is based on Dr. Vincent Tuohy’s earlier work, which was published in Nature Medicine in May 2010 under the title: An autoimmune-mediated method for preventative breast cancer immunization. This study indicated that activating the immune system against α-lactalbumin safely and successfully prevented mammary tumors in mice, and that a single vaccination prevented the development of mammary tumors in a mouse model while decreasing the growth of pre-existing mammary tumors.
It is known that the research funding for this clinical trial also includes charitable donations from more than 20,000 people over the 10 years since the paper was published. The clinical trial will be conducted in 18–24 patients who have completed treatment for early-stage triple-negative breast cancer within the past three years and are currently tumor-free but at high risk of recurrence. During the course of the study, subjects will receive three vaccinations, two weeks apart, and researchers will closely monitor side effects and immune response in a clinical trial that is expected to be completed in September 2022.
The scientists also stated that a clinical study of the breast cancer vaccine will be conducted in healthy women with a high genetic risk of breast cancer who have mutations in the BRCA1 or BRCA2 genes and are at high risk of developing breast cancer.
According to Dr. Vincent Tuohy, the study’s leader, the vaccine strategy has the potential to be applied to other types of cancer that face aging, such as ovarian cancer and endometrial cancer.
Vaccines for infectious diseases given to children after birth have considerably enhanced human life expectancy, and if successful, this cancer vaccine could transform the way humans manage the onset of cancer in adults, hence increasing human life expectancy.