Breast cancer vaccine trial results are encouraging
The vaccine was developed at the Washington University School of Medicine in St Louis, and the results of the trial have been published in Clinical Cancer Research.
The vaccine's target is a protein called mammoglobin-A, which is found almost exclusively in breast tissue.
"Being able to target mammaglobin is exciting because it is expressed broadly in up to 80% of breast cancers, but not at meaningful levels in other tissues," said breast cancer surgeon and senior author William E. Gillanders. "In theory, this means we could treat a large number of breast cancer patients with potentially fewer side effects."
The vaccine primes a type of white blood cell to seek out and destroy mammoglobin-A. It is not effective in breast cancer patients whose tumours do not produce mammoglobin-A.
In the study, 14 patients with metastatic breast cancer that produced mammoglobin-A were vaccinated in a phase one trial designed mainly to test the vaccine's safety. Some tenderness, or flu-like symptoms were reported, but no severe side-effects.
Of the 14 vaccinated patients, one half showed no cancer progression one year later. In a control group of similar patients who were not vaccinated, one fifth showed no cancer progression after one year.
Gillanders and his colleagues are now planning a larger clinical trial on newly diagnosed breast cancer patients.
"If we give the vaccine to patients at the beginning of treatment, the immune systems should not be compromised like in patients with metastatic disease," Gillanders said.