Breast cancer vaccine results promising, moves to next stage in clinical trials

“This vaccine is designed eventually to prevent breast cancer,” said Amit Kumar, CEO of Anixa Biosciences. “So, one day, we hope to be able to give it to pretty much every woman in the world who’s worried about breast cancer.”

Anixa is developing the vaccine, which is entering phase two of a clinical trial at the Cleveland Clinic.

According to the American Cancer Society facts and figures for 2024-2025, approximately 1 in 8 women (13%) will be diagnosed with invasive breast cancer, and 1 in 43 (2.3%) will die from the disease. An additional 2,790 men will be diagnosed with breast cancer, and 530 are expected to die from the disease.

“This trial is initially focused on the most lethal form of breast cancer, which is known as triple-negative breast cancer,” Kumar told WTOP. “But we anticipate that it’ll work for other types of breast cancer as well.”

The vaccine targets a lactation protein, alpha-lactalbumin, which is not found after lactation in normal aging breast tissues but is present in most triple-negative breast cancers.

Cancer begins with a single cell, then doubles to two, then four, then eight, cells — eventually becoming a multibillion cell tumor that can be seen on a mammogram.

If [the vaccine] has properly trained in that patient’s immune system, at the 2-cell, 4-cell or 8-cell stage, the immune system will destroy those cells, and so they never have a chance to become a tumor,” said Kumar.

How the breast cancer vaccine has been tested so far

In the phase one trial, a group of 26 patients was broken down into three categories, said Kumar. In this phase, researchers are studying whether the drug is effective and safe and identifying the optimal dosage.

Group A was made up of women already diagnosed with triple-negative breast cancer — an aggressive form that is notoriously difficult to treat. These patients have already gone through treatment — including surgery, chemotherapy and radiation — and are currently cancer-free, but at high risk for recurrence.

“Anywhere from 40% to 80% of these women will have a recurrence within 5 years,” said Kumar. “So we’re giving them the vaccine to see if we can teach their immune systems to target the cancer, if and when it returns.”

Group B is made up of patients who are cancer-free, but at high genetic risk, and have elected to voluntarily have a preventative mastectomy to lower their risk.

“We’re going to vaccinate these women before their surgeries, and after their surgery we’re going to be able to examine their purportedly healthy tissue,” said Kumar.

The third cohort, Group C, are patients with early-stage triple-negative breast cancer who received chemotherapy and surgery, and are being treated with immunotherapy. Liquid biopsy shows these patients have traces of cancer remaining in their blood, which puts them at high risk for developing another tumor.

“We’re going to give these women the vaccine in addition to existing standard of care therapy, to see if the vaccine can act synergistically and prevent their cancers from coming back,” Kumar said.

The results have been promising, and the side effects minimal, said Kumar.

“Over three-quarters of these women are showing a good, robust immune response, and others are showing a modest immune response,” he said. “The only side effect these women felt was irritation at the site of injection, so no headaches, no pain, no abnormal laboratory values.”

What’s next in the clinical trial

In phase two — the larger part of the study — Kumar said they’ll be treating women who have just recently been diagnosed with early stage breast cancer, and are heading toward surgery.

“Typically, standard of care is to give these women chemotherapy in what’s known as the ‘neoadjuvant setting,’ which is before surgery,” said Kumar. “The intent is to reduce their tumor burden, so perhaps surgery can be less aggressive and also to lessen the chance of a recurrence after the surgery.”

Half of the women in phase two of the study will get that current standard-of-care treatment. The other half will receive standard-of-care treatment and also get the vaccine.

“We’re hoping that the vaccine group fares much better than the standard of care group, which is what we expect,” said Kumar. “The question is, will it be 60% effective, 80% effective, or is it 100% effective? — which is what we saw in the animal studies.”

Eventually, an even-larger phase three trial would have half the number of patients receiving the vaccine, the other half getting a placebo, in addition to standard of care treatment.

Kumar said the plan is for the vaccine to come to market in stages.

“The first will be for women battling breast cancer, the second will be for patients who have already had breast cancer and worry about it returning. And the third will be women who have never had breast cancer, to prevent breast cancer in the future,” said Kumar. “We believe that the first application, for women who are battling breast cancer, could be available within four to five years.”

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