Breast Cancer Vaccine Trial May Blaze Trail to Stopping Cancer

In In The News by Barbara Jacoby


A trial is underway for a breast cancer vaccine. Scientists are hoping this latest immunotherapy will help keep patients from developing cancer again.

Researchers are hoping that they’ll soon break ground in a new medical frontier.

Vaccines that can stop cancer.

Currently, the only vaccine designed to prevent cancer is the HPV vaccine.

However, that shot protects against the human papillomavirus that leads to cervical cancer, not the cancer itself.

But a new study taking place at sites across the United States, including Mount Sinai Hospital in New York, is researching if a vaccine can be used to prime the immune system to fight cancer cells from developing into a tumor.

The research is part of the growing field of medicine called immunotherapy. In this field, doctors attempt to harness the immune system in a variety of ways to fight cancer.

Last summer, the first gene-therapy immunotherapy treatment was approved by the U.S. Food and Drug Administration (FDA).

That drug, called Kymriah, reengineers the immune cells to fight a certain kind of leukemia.

Looking for help from the cancer cell

In this trial, researchers are studying if a vaccine can help women who have already undergone treatment for nonmetastatic breast cancer and are in remission.

The trial is currently in the phase II stage. In this stage, researchers look for signs of the vaccine’s effectiveness.

The team is focused on targeting a specific protein called human epidermal growth factor receptor 2 (HER2). According to the Mayo Clinic, HER2 “promotes the growth of cancer cells.”

About 1 in 5 women with breast cancer are designated as having HER2-positive breast cancer. That means they have high levels of this protein in their cancer cells. 

Doctors already use drugs — including one immunotherapy drug called Herceptin — that target these proteins by blocking specific receptors on the tumor.

But as many as 60 to 70 percent of women with breast cancer have moderate levels of HER2.

Even though they’re not considered to have HER2-positive breast cancer, scientists have been looking to see if HER2 treatment could help them as well.

Dr. Amy Tiersten, the lead investigator of the study at Mount Sinai and a professor of medicine, hematology, and medical oncology at the Icahn School of Medicine at Mount Sinai, said they hope to find a way to help more women by combining Herceptin treatment and a vaccine derived from part of the HER2 protein.

“There are many, many vaccine trials going on. It’s part of the revolution of immunotherapy,” she told Healthline. “Vaccines are a little bit different, but they’re part of the same idea.”

In this trial, women get both Herceptin and a new vaccine that’s derived from the HER2/neu peptide E75. This peptide is a piece of the HER2 protein that can help cancer cells grow.

The hope is that this peptide will encourage the immune system to look for and fight microscopic cancer cells before they can develop into a large tumor.

“Only 20 percent of [breast cancer] patients are HER2 positive,” Tiersten said. So, getting HER2 therapy to work for “a much larger group of patients would be a huge” advantage.

Some women are getting a placebo instead of a vaccine. This is so researchers can determine whether or not there’s benefits in getting the inoculation.

If the researchers find that the vaccine works, it could mean people who would’ve had a reoccurrence of cancer remain fully cancer-free, or cancer-free for a longer period of time.

Tiersten points out this is just one part of a growing immunotherapy field that’s already changing how doctors and patients battle cancer.

Other drugs called “checkpoint inhibitors” — which take “the brakes” off the immune system — have already been approved to treat some cancers, such as lung cancer.

Now with the vaccine trial, Tiersten and her patients hope to prove that manipulating the immune system to fight cancer with a vaccine will save lives.

Tiersten and her team will do this by “vaccinating patients with a very small amount of a protein that’s expressed on these cells, and then allowing the patient’s own immune system to find any microscopic cells that the chemotherapy or other therapies may have missed, and thereby reduce the risk of occurrence,” she said.

The patients who sign up

The trial will include about 300 patients.

It’s ongoing and scheduled to end in 2020.

It’s not yet clear if the vaccine will be successful enough that patients outside of the trial could get the vaccine in the future.

However, one of Tiersten’s patients said that she knew immediately she wanted to be a part of the study.

Norma, a lawyer in New York City, wasn’t worried about taking part in an experimental trial after receiving a diagnosis of stage 3 breast cancer last year.

For me, it was never even an option or question if I would do it,” she told Healthline.

Norma, who didn’t wish to have her last name used, said she was determined to do everything she could to stay cancer-free, in part because of her 10-year-old son.

“I really wanted to have the opportunity to take this drug and to be part of this trial,” Norma, 49, said. “When you’re fighting and fighting with everything you have… you got to do everything you can.”

Louise Mimicopoulos, a senior vice president of merchandising and accessories at Ralph Lauren, is in remission after receiving a diagnosis of stage 3 breast cancer.

She wanted to be a part of the study to help other women in the future.

“Somewhere I can help someone else down the road,” she said. “It had nothing to do with myself. It really was to hopefully help someone else.”

Other immunotherapy experimental treatments have sometimes resulted in dangerous side effects with the immune system attacking important systems in the body. But Tiersten said the only side effects they’ve seen so far in this study is some redness and irritation around the site where the shots were administered.

Both Norma and Mimicopoulos said they had some irritation from the vaccine.

How breakthroughs have helped patients

Dr. Melissa Fana, chief of breast surgery at Southside Hospital in Bay Shore, New York, said the trial shows how far the medical field has come in understanding and treating breast cancer.

“I’m not surprised at the ongoing trial, or even that it may be possibly promising,” she said. “We’ve had a breakthrough in breast cancer understanding, which is guiding treatment in the last decade.”

Fana said doctors now understand much more about the biology of the tumor. Knowing this is key in treating it effectively.

In the past, she said, doctors thought the cancer’s size and the aggressiveness of treatment — including surgeries like radical mastectomies — determined the patient’s outcome.

Fana explained that new research has shown some small tumors should be dealt with aggressively and with chemotherapy. Other larger tumors may be slow-growing. They can be effectively treated with other less invasive treatments.

As a result of this research, doctors have been able to target different kinds of breast cancer with different drugs that are more effective and often have less side effects for the patient.

“Cancer is an ugly word. It’s intimidating and scary, but what it is essentially is an abnormal cell, a cell that’s lost its internal clock,” Fana said. “[If we can start learning] how we can make it sensitive to therapy… then we are more effective at treating the breast cancer.”