A small safety trial of a breast cancer has proven safe in addition to suggesting the vaccine will slow cancer progression.
The study was published on December 1st in Clinical Cancer Research.
Researchers at Washington University School of Medicine in St. Louis are developing the vaccine. The vaccine is meant for patients with breast cancers that express a protein only found in breast tissue called mammaglobin-A. The protein’s role in healthy tissue is unclear.
The vaccine causes the body’s immune system to home in on the mammaglobin-A protein. The vaccine primes a type of white blood cell, part of the body’s adaptive immune system to seek out and destroy cells with the mammaglobin-A protein.
Research shows that tumors express a high level of the protein, which is present in up to 80% of breast cancers. Therefore if the vaccine makes it to the market, it could potentially be beneficial to an exorbitant number of breast cancer patients. In the smaller proportion of breast cancer patients whose tumors do not produce mammaglobin-A, this vaccine would not be effective.
The trials data shows that the patients had few side effects beyond eight mild to moderate like tenderness a vaccination site, flu-like symptoms and rash. There were no severe side effects. The trial was meant to assess the safety of the vaccine, but the preliminary research showed that the vaccine appears to have slowed cancer progression in many of the patients. About half of the patients had no cancer progression one year after vaccination. Compared to the control group of 12 unvaccinated patients, only one fifth had no progression.
Although the initial trial was small, researchers say their effectiveness findings are statistically significant. The next steps are larger trials intended to officially assess how effective the vaccine truly is.