A first-of-its-kind breast cancer vaccine is set to begin phase I trials. The trial will be the first to test a vaccine against triple-negative breast cancer – the most aggressive and deadly form of breast cancer – in humans. That’s a whole lot of firsts, it's no wonder the scientists behind it are so excited.
“Long term, we are hoping that this can be a true preventive vaccine that would be administered to healthy women to prevent them from developing triple-negative breast cancer, the form of breast cancer for which we have the least effective treatments.,” Dr G. Thomas Budd, principal investigator of the study, said in a statement.
The Cleveland Clinic announced the trial on Tuesday, following the US Food and Drug Administration’s approval of an investigational new drug application for the vaccine. Based on two decades worth of lab work and animal research, the world-first human trial will take place at Cleveland Clinic’s Lerner Research Institute and will initially include 18 to 24 early-stage triple-negative breast cancer survivors who are at high risk of recurrence. The researchers hope that, following the success of this first step, the vaccine could be trialed on healthy people at high risk for the disease, such as those with BRCA1 gene mutations.
But first, the trial aims to determine the maximum tolerated dose of the vaccine and define and optimize the body’s immune response to it.
To do this, participants will be given three shots, each two weeks apart. Starting with a low dose in just a few patients, this will gradually be increased to higher doses and will eventually include more participants. The individuals involved will be monitored for 84 days after the last shot is administered, to measure any potential side effects.
“Once we’ve figured out how much of the vaccine we can give, we’ll look at its effects on the immune system,” Budd told the Cleveland Clinic. “That will help us know whether the vaccine is doing what we want it to do, and then we’ll expand each dose level.”
Triple-negative breast cancer accounts for 12-15 percent of all breast cancers, but is the most deadly subtype, killing nearly a quarter of patients within five years of diagnosis. It is also notoriously difficult to treat with hormone therapy and other targeted drugs are ineffective – the only way to prevent it is mastectomy.
The milk protein α-lactalbumin – typically expressed only when a person is lactating – is expressed in excess in 70 to 80 percent of triple-negative breast cancers. It is this protein that the vaccine will target, kick-starting the immune system to attack the cells that produce it. The vaccine will also include a drug that alerts the immune system to α-lactalbumin, enhancing the body’s immune response.
Should the trial, expected to finish in September 2022, prove the vaccine effective in doing so, the researchers hope it could improve the outcomes of people at risk of breast and other types of cancer.
“This vaccine strategy has the potential to be applied to other tumor types,” said Dr Vincent Tuohy, the primary inventor of the vaccine. “Our translational research program focuses on developing vaccines that prevent diseases we confront with age, like breast, ovarian and endometrial cancers. If successful, these vaccines have the potential to transform the way we control adult-onset cancers and enhance life expectancy in a manner similar to the impact that the childhood vaccination program has had.”
While Dr Budd admitted to the Cleveland Clinic that it could take years to get to this point, he remains optimistic: “we have to start somewhere — and we’re really excited to take our first step.”