A study in JAMA Oncology in November 2022 suggests that researchers in the US are making progress with an experimental vaccine against breast cancer. Led by Dr Mary (Nora) L. Disis of the University of Washington Medicine Cancer Vaccine Institute, the team indicate success in Phase I clinical trials.  

Breast Cancer 

The WHO states that 2.3 million women were diagnosed with breast cancer in 2020. The NHS estimates that 1 in 8 women are diagnosed with the cancer throughout their lifetime. Many are over the age of 50, but not all. Only 1% of breast cancer diagnoses occur in male patients. Dr Kotryna Temcinaite of Breast Cancer Now told Medical News Today that it is not a “single disease, which makes it more difficult to treat”.  

“There are many types of breast cancer and treatments that work well for some people, may not work as well for others.” 

Calling for “kinder and smarter” treatments, she indicated the importance of “further research” into the disease. Dr Disis, lead author of the recent study, explained that current treatments often lead to “disease recurrence” when a small amount of cancer remains undetected. Thus, vaccines are required to fill the gap. 

“Vaccines will stimulate t-cells which can be programmed to hunt down these last remaining cells in the body and kill them. Stimulating effective immunity is the only way I know we can sterilise the body from all breast cancer cells.”  

UW’s Phase I trial  

The trial was a nonrandomised clinical trial of 66 patients with “advanced-stage ERBB2-positive breast cancer”. Formally known as HER2, ERBB22 is a key tumour protein. High levels of ERBB2-specific type 1 T cells are “associated with favourable clinical outcomes after trastuzumab therapy”. Unfortunately, only a “minority of patients develop measurable ERBB2 immunity after treatment”.  

The researchers determined to assess the safety and immunogenicity of 3 doses of a plasmid-based vaccine, which encoded the ERBB2 intracellular domain. Over two periods, 2012-2013, and 2021-2022, they collected and analysed data. The vaccine was “administered intradermally once a month” with “soluble granulocyte-macrophage colony-stimulating factor as an adjuvant for 3 immunisations”. Medical News Today reports that the most common side effects associated with the injection were flu-like symptoms and fatigue.  

“Participants who received the higher vaccine doses of 100 μg and 500 μg demonstrated a stronger immune response than those who received the 10ug dose, but there was no significant difference between the immune responses to the 100ug and 500ug doses.” 

The future of vaccines 

Dr Disis hopes there is a “good chance” that we will see breast cancer vaccines in about 5 years. Many groups are “working on ‘next-gen’ vaccines with very effective delivery technologies and adjuvants” she says. However, this progress is not limited to breast cancer. A range of possibilities are being explored in Washington alone, with programmes including ovarian cancer, colon cancer, and prostate cancer.  

For this vaccine, the next step is to “formally test” the observations of this study to see if it does “prevent disease recurrence”.  

For more on cancer vaccine advances at the World Vaccine and Immunotherapy Congress in San Diego 2022 or the World Vaccine Congress in Washington 2023, get your tickets today.