First-of-its-kind preventative breast cancer vaccine begins human trials

After two decades of preclinical research the first phase of human trials are set to begin testing a unique preventative breast cancer vaccine that is designed to target a protein commonly expressed by triple-negative breast cancers.

Around 15 percent of all breast cancers are classified as triple-negative breast cancers, so-called because they lack one of the three main molecular characteristics commonly targeted by modern treatments. This means triple-negative breast cancers are particularly deadly.

A landmark study published in 2010 proposed a novel target for a new kind of preventative breast cancer vaccine. The research indicated breast cancer cells often express high levels of a protein called alpha-lactalbumin. Triple-negative breast cancer cells in particular were found to commonly express the protein making it a compelling target for a vaccine.

“The general idea behind the vaccine is that alpha-lactalbumin could be a so-called immunologic target – where we can stimulate the immune system to attack cells that make that protein,” explains Thomas Budd, principle investigator on the trial.

Animal studies have found training the immune system to target cells producing alpha-lactalbumin can both inhibit the growth of breast tumors and even prevent them from appearing in the first place. Vincent Tuohy, who has been working on this project for almost 20 years, says the goal is to produce a true prophylactic vaccine that can be administered to those at high-risk of developing breast cancer.

“What we’re trying to do is what we call primary prevention,” says Tuohy. “It’s actually preventing the disease from occurring to begin with – it was never there to begin with. We’re not trying to prevent recurrence. We’re trying to prevent the emergence of the tumor and prevent it from ever happening.”