The First Vaccine for Triple-Negative Breast Cancer
Researchers are working on a first-of-its-kind vaccine to prevent triple-negative breast cancer (TNBC) from developing.
It’s called TNBC because the tumor cells test negative for three key receptors:
Estrogen and progesterone are female hormones. HER2 is a protein that helps cells grow.
Why does this matter? Because there are several effective treatments for breast cancers that have those receptors. TNBC is typically harder to treat because it doesn’t respond to hormone therapies or targeted therapies.
TNBC tends to grow and spread faster than other types of breast cancer. It has a high rate of recurrence and the outcome is usually less favorable. About 10 percent to 15 percentTrusted Source of all breast cancers are triple negative.
In this article, we’ll discuss who might benefit from the vaccine and the status of clinical trials.
What is the vaccine for triple-negative breast cancer?
This experimental vaccine is in the early stages of testing with humans.
The long-term goal is to vaccinate healthy people who are at a high risk of developing TNBC. You might be at a high risk of TNBC if you carry certain inherited gene mutations, particularly BRCA1. Such a vaccine might also be helpful to those with a strong family history of breast cancer.
Anyone can develop TNBC. But it’s often more likely to affect women of African or Hispanic descent. It also tends to occur in women under 40 years old.
In October 2021, Anixa Biosciences and Cleveland Clinic announced the start of dosing patients in a phase 1 trial. The Cleveland Clinic conducted the groundwork for this 2010 study with miceTrusted Source.
The vaccine targets a milk protein called alpha-lactalbumin, or a-lactalbumin. Sometimes referred to as a “retired protein,” it’s not usually found in the tissues of nonlactating people. But it does occur in most cases of TNBC.
The hope is that the vaccine, also called the aLA breast cancer vaccine, will work much like vaccines that cure infectious diseases. That is, it will stimulate the body’s immune system to clear this specific type of cancer.
The idea is to teach the immune system to clear out cells that express a-lactalbumin. In theory, this will prevent tumors from forming.
In the current phase 1 trial, researchers aim to determine the maximum tolerable dose. Participants will get 3 vaccinations in varying doses, 2 weeks apart.
What challenges does the vaccine face?
The phase 1 trial is small. It will include only 30 participants. All must have completed treatment for early-stage TNBC within the past 3 years. All must be currently tumor-free, but considered at a high risk of recurrence.
Because this is the first human trial of the vaccine, the researchers will keep a careful eye out for toxicities and adverse events. Among those excluded from this trial are people who:
- are pregnant or plan to become pregnant
- are breastfeeding or plan to breastfeed
- take oral contraceptives
- have a hormonal IUD
After determining the maximum tolerable dose, the researchers will see if they can identify at least one participant who mounts an immunologic response. If so, they’ll expand successively lower doses to a total of six participants. The researchers will then assess their immunologic responses. If there are no responses, enrollment will end.
Phase 1 human trial study objectives
The objectives of the phase 1 study are to determine:
- the maximum tolerable dose
- any dose-limiting toxicities
- the lowest dose that prompts an immunologic response
Participants can choose to participate in long-term follow-up for late toxicity and survival:
- every 3 months for 2 years
- every 6 months for an additional 3 years
- and annually for 10 years
Results from the 2010 study with mice
The 2010 mice studyTrusted Source suggested that a vaccine targeting a-lactalbumin may provide safe and effective prevention for breast cancer.
However, it’s far too soon to know how well it may work in humans. It’s also too early to identify potential safety concerns or what the short- and long-term side effects may be.
Researchers can provide more information on these issues following this and subsequent larger trials.
What future trials will focus on
Researchers expect future trials to involve women who:
- are cancer-free
- are at a high risk of breast cancer
- decide on a bilateral mastectomy to lower their risk
When do researchers believe the vaccine will be available for use?
This vaccine is still in the experimental stage. It still needs the Food and Drug Administration (FDA) approval, and there’s a long way to go until it’s available for the public.
Researchers expect the phase 1 trial to end in September 2022. If successful, the vaccine can then advance to phase 2 and phase 3 trials.
Even if all goes well, the vaccine is at least several years away from gaining approval for general use.
TNBC is a particularly aggressive form of the disease. And because it does not carry estrogen, progesterone, or HER2 receptors, treatment options are more limited than for some other types of breast cancer.
Researchers are working on a vaccine to prevent TNBC in those who are at a high risk. The vaccine targets a protein called a-lactalbumin. This protein isn’t usually present in the cells of nonlactating people. However, it is present in most cases of TNBC.
The hope is that the vaccine will function similarly to vaccines that prevent infectious diseases. It will teach the immune system to clear out the protein and prevent tumors from forming.
The phase 1 clinical trial is underway at Cleveland Clinic. Researchers anticipate a completion date of September 2022. If successful, phase 2 and phase 3 trials will follow.
The vaccine is promising, and there’s reason for hope. But even if trials go well, it will be at least several years before the vaccine can receive approval for general use.
Medically reviewed by Teresa Hagan Thomas PHD, BA, RN
Posted in: Research