Experimental breast cancer vaccines can safely produce anti-tumor immunity

Science and Technology Daily News (Reporter Liu Xia) Scientists at the University of Washington School of Medicine published a paper in the latest issue of the Journal of the American Medical Association Oncology that an experimental vaccine against breast cancer safely produces a strong immune response to a key tumor protein, and the vaccine may be able to treat different types of breast cancer
.

The vaccine targets the protein human epidermal growth factor receptor 2 (HER2), and the phase I trial is designed to evaluate the safety of the vaccine and see if it will produce an immune response
to HER2.

HER2 appears on the surface of many cells, but in up to 30% of breast cancer patients, HER2 is overproduced in hundreds of times as many as normal cells
.
These "HER2-positive" cancers tend to be more aggressive and more likely to recur
after treatment.
But HER2 overproduction can also trigger a beneficial immune response, and once a patient has this response, the cancer is less likely to recur and overall survival is longer than that of a patient
who does not develop this immune response.

To stimulate this immune response, the researchers developed a DNA vaccine that contains DNA instructions
for the target protein.
Once the vaccine is injected into the body, its DNA is absorbed by cells at the injection site and begins to produce proteins encoded in the vaccine's DNA instructions, which the cells then supply to the immune system to stimulate a strong cytotoxic immune response
.

Sixty-six women with metastatic cancer participated in the study, divided into three groups and given low-dose (10 micrograms), medium (100 micrograms), and high-dose (500 micrograms) vaccines, in addition to granulocyte-macrophage colony-stimulating factor
, which promotes cytotoxic immune responses.

The researchers followed the participants for 3-13 years (an average of 10 years), and the results showed that the vaccine was very safe, and the most common side effects experienced in half of the patients were very similar to those after receiving the new crown pneumonia vaccine: redness and swelling at the injection site, possibly accompanied by fever, chills and flu-like symptoms
.
The vaccine has also been successful in stimulating cytotoxic immune responses, and patients who receive moderate doses of the vaccine have the strongest
immune response.

Lead author Mary Diesel said: "80% of these women are still alive
.
If the results of the subsequent phase II trial are also optimistic, we will quickly move forward with the final phase III trial, and we are likely to develop a vaccine
that can effectively treat breast cancer.
”