Breast Cancer Vaccine set for Clinical Trials
The new year is kicking off with hopeful news about a breast cancer vaccine. The US Food and Drug Administration (FDA) approved a new vaccine for triple-negative breast cancer to enter clinical trials. Invented and developed by Cleveland Clinic immunologist Dr. Vincent Tuohy, the vaccine has been 10 years in the making.
Triple-negative breast cancer is an aggressive form of breast cancer with limited treatment options. According to the Center for Disease Control (CDC), triple-negative breast cancer (TNBC) does not have any of the receptors that are commonly found in other types of breast cancer. This makes this type of breast cancer more difficult to target and treat with drugs. So far, chemotherapy has been the mainstay of treatment. The demographics of TNBC is also different from other breast cancer subtypes, targeting predominantly women under 40yrs of age, Black women, and women who carry the BRCA1 gene mutation.
The Cleveland clinic is partnering with Anixa Biosciences, who has an exclusive worldwide license to the new technology. Pre-clinical trials conducted on animals showed 100% of mice that were not vaccinated and got a placebo drug, developed breast cancer and died. Phase 1 of the human clinical trials will begin as soon as possible. The trials will include both women and men and will hopefully be completed within two years.
Women who intend to breast feed in the future will not be candidates. This is because the vaccine is designed to attack alpha-lactalbumin-expressing cells. By attacking these cells, there will likely be damaging effects to milk production. “Most triple-negative breast cancers express alpha-lactalbumin,” Tuohy says. “It is a mistake that the tumors make because they have no default inhibition mechanisms through progesterone and estrogen signaling that would ordinarily prevent the expression of this protein.” He describes the vaccine mechanism as “simply taking advantage of this mistake.”
Dr. Amit Kumar, President and CEO of Anixa stated, “We are pleased that the FDA authorized human clinical trials of our potentially paradigm-shifting vaccine for the prevention of breast cancer. This approval will eventually lead to recruitment of patients and initiation of the trial.”
There are several breast cancer vaccines currently in development across the globe. Although these potential advances are very exciting, unfortunately it will likely be a while before patients interested in a vaccine will have access to it.
FDA Approves New Drugs For Metastatic Breast Cancer
There was very hopeful news this week for many patients with metastatic (stage 4) breast cancer.
The FDA has approved the use of the drug Tukysa (tucatinib) in combination with chemotherapy (trastuzumab and capecitabine) for the treatment of locally advanced HER2+ breast cancer that can’t be removed with surgery, or for stage 4 disease (including brain metastasis) in patients who have already received one or more prior treatments. In trial studies, 33% of patients treated with Tucatinib in combination with chemotherapy did not see their cancer progress in the first year and 2-year survival after starting treatment was 44.9%.
Based on the favorable results of a recent phase 2 study, the FDA also announced a fast-tracked approval of the drug Trodelvy (sacituzumab govitecan-hziy). The drug is specifically for patients with relapsed or refractory metastatic triple-negative breast cancer who have received at least two prior therapies for metastatic disease. According to the manufacturer, the drug specifically targets the receptor that encourages cancer growth and spread in the body. The study for Trodelvy included 108 patients. More that half of patients with stage 4 disease who responded to the drug maintained their response for six months or more. Some patients also experienced reduced tumor sizes. Encouragingly, 16.7% of patients maintained their positive response to the drug for a year or more.
As always, before beginning any new therapy, it is important to fully discuss all the potential benefits and side effects with your medical oncologist.
Addressing Disparities between Black and White Women with Triple-Negative Breast Cancer
Multiple studies have shown that African-American women have poorer survival outcomes after a breast cancer diagnosis than white women. One significant contributing factor to these findings is that most studies include all types of breast cancer together. This approach can skew results as white patients have a higher incidence of estrogen receptor-positive breast cancer than black women, which has better outcomes than the more aggressive triple-negative form of the disease. A summary of the different types of breast cancer can be found here.
Survival rates between black and white women with triple-negative breast cancer (TNBC) appear to equalize when these cancers are found early with screening mammograms, a new JAMA study suggests. However, TNBC still remains about twice as common in black women.
This study emphasizes the importance of screening and early detection, particularly in traditionally underserved black women. Unfortunately, we still don’t know why black women experience a much higher rate of TNBC.
Immunotherapy Improving Treatment of Triple Negative Breast Cancer
Triple-negative breast cancer is so called because, unlike more common forms of breast cancer, its cells do not have receptors for estrogen, progesterone, or the HER2 protein.
Triple-negative cancer makes up only about 10-15% of diagnosed breast cancers, but is one of the most aggressive and deadly forms of the disease. It is also more likely to affect younger women under 50. In most cases, triple-negative tumors quickly become resistant to chemotherapy and spread to other parts of the body.
Over the last few years, immunotherapy — a treatment that boosts’ the body’s defenses against infection and diseases — has been gaining ground as a potential therapy for several different types of cancer, including breast cancer.
A recent phase 3 study, published in the New England Journal of Medicine, included over 900 women in 41 countries randomly assigned to one of two treatment groups: one group received the immunotherapy drug atezolizumab (a monoclonal antibody drug) together with chemotherapy, the other group was given a placebo with chemotherapy.
“In a combined treatment approach, we are using chemotherapy to tear away the tumour’s ‘immune-protective cloak’ to expose it as well as enabling people’s own immune system to get at it” said lead author of the study, Professor Peter Schmid.
Patients who received the immunotherapy drug along with chemotherapy extended overall survival by 10 months, reducing the risk of death or disease progression by up to 40%.
