The incidence of breast cancer is caused by a multitude of factors in your body, one of these being hormonal imbalances. Estrogen, a group of hormones that promotes the development of the female reproductive system (think of it like the opposite of testosterone), can often play a major role in promoting breast cancer tumor growth.
Mutations in the estrogen receptor ESR1 are often present in advanced or metastatic breast cancer. They also cause the tumor to be resistant to endocrine or hormonal therapy. Hormonal therapy is essential to slowing/stopping the growth of a hormone-sensitive tumor so therapies like chemo and radiation can eradicate the tumor completely. ESR1 mutations have been an unaddressed issue in breast cancer therapy, and often mean that metastatic patients can never fully eradicate their tumor.
Elacestrant, a novel drug developed by Stemline Therapeutics, addresses this unmet need by blocking estrogen from binding to its receptor, therefore hindering cell growth. It has currently been approved by the FDA for post-menopausal patients with either ER-positive, HER2-negative, or ESR1-mutated advanced or metastatic breast cancer. It is now sold under the brand name Orserdu.
Elacestrant is the first estrogen receptor degrader to demonstrate an improved progression-free survival (PFS) over the standard of care in patients with ESR1 mutations. PFS is the length of time after the treatment of the tumor that the patient is able to live with the tumor without it worsening.
If you are a patient with hormone-sensitive advanced or metastatic breast cancer, you might want to talk to your doctor to see if this novel treatment is for you.
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