On Oct. 12, 2021, the U.S. Food and Drug Administration (FDA) approved the targeted therapy Verzenio (chemical name: abemaciclib) in combination with either tamoxifen or an aromatase inhibitor after surgery to treat early-stage hormone-receptor-positive HER2-negative node-positive breast cancer with a high risk of recurrence (the cancer coming back) and a Ki-67 score of 20% or higher.
Doctors call treatments given after surgery adjuvant treatments. So Verzenio taken after surgery is considered an adjuvant treatment.
Verzenio is a cyclin-dependent kinase 4/6 (CDK4/6) inhibitor. A kinase is a type of protein in the body that helps control cell division. Verzenio works by stopping cancer cells from dividing and growing. Verzenio is a pill taken by mouth.
Verzenio is the first CDK4/6 inhibitor to be approved for adjuvant treatment of early-stage breast cancer.
Verzenio is also used to treat advanced-stage and metastatic breast cancer:
- In combination with an aromatase inhibitor, Verzenio is used as the first hormonal therapy to treat advanced-stage or metastatic hormone-receptor-positive, HER2-negative breast cancer in postmenopausal women. Arimidex (chemical name: anastrozole), Aromasin (chemical name: exemestane), and Femara (chemical name: letrozole) are aromatase inhibitors.
- In combination with Faslodex (chemical name: fulvestrant), Verzenio is used to treat hormone-receptor-positive, HER2-negative metastatic or advanced-stage breast cancer if the cancer grew after hormonal therapy treatment.
- Verzenio is used alone to treat hormone-receptor-positive, HER2-negative metastatic or advanced-stage breast cancer if the cancer grew after hormonal therapy treatment and earlier chemotherapy for metastatic disease.
Advanced-stage breast cancer is either locally advanced or metastatic. Locally advanced breast cancer is breast cancer that has spread to tissue near the breast, but not to parts of the body away from the breast. Metastatic breast cancer is breast cancer that has spread to parts of the body away from the breast, such as the bones or liver.
Ki-67 is a protein in cells that increases as they prepare to divide into new cells. A staining process can measure the percentage of tumor cells that are positive for Ki-67. The more positive cells there are, the more quickly they are dividing and forming new cells. In breast cancer, a result of less than 10% is considered low, 10% to 20% is considered borderline, and more than 20% is considered high.
Cancer characteristics that lead to high recurrence risk
The characteristics of early-stage hormone-receptor-positive HER2-negative breast cancer that give it a high risk of recurrence are as follows:
- the cancer is found in four or more lymph nodes
- the cancer is 5 cm or larger in size
- the cancer is grade 3, which means the cells look very different from normal cells and are growing quickly in disorganized, irregular patterns
- the cancer has high levels of Ki-67
Approval based on monarchE results
Verzenio’s approval to treat certain early-stage breast cancers after surgery is based on results from the monarchE study.
The study found that adding Verzenio to hormonal therapy after surgery to remove early-stage hormone-receptor-positive HER2-negative breast cancer with a high risk of recurrence lowers recurrence risk by about 25% versus using hormonal therapy alone. Specifically, adding Verzenio to hormonal therapy lowered the risk of distant recurrence — the cancer coming back in a part of the body away from the breast, such as the bones or liver — by about 28%.
“The design and results of the monarchE study are practice-changing and represent the first advancement in adjuvant treatment of hormone-receptor-positive HER2-negative breast cancer in a very long time,” Sara Tolaney, M.D., MPH, of the Dana-Farber Cancer Institute and monarchE investigator, said in a statement. “This FDA approval for Verzenio in combination with endocrine therapy in the early breast cancer setting has the potential to become a new standard of care for this population. We are encouraged by the marked reduction in the risk of recurrence even beyond the 2-year treatment period in these patients, and I'm grateful to be able to offer this as a treatment option to my patients.”
Verzenio side effects
Like almost all breast cancer medicines, Verzenio can cause side effects, some of them severe.
The most common side effect of Verzenio is diarrhea, and for most people it begins during the first week or so of treatment. If you’re prescribed Verzenio, your doctor will likely give you an anti-diarrheal medicine like Imodium (chemical name: loperamide) to take preventively.
Other common side effects of Verzenio are:
- low white blood cell counts
Less commonly, Verzenio may cause serious side effects, including:
- liver problems
- severe neutropenia (very low white blood cell count)
- blood clots
- severe lung inflammation
What this means for you
If you’ve been diagnosed with early-stage hormone-receptor-positive HER2-negative node-positive breast cancer with high Ki-67 levels and a high risk of recurrence and are deciding on treatments after surgery, you have a new option to consider.
After reviewing your unique situation and personal preferences, you and your doctor can decide if adding Verzenio to hormonal therapy after surgery is a good option for you.
Learn more about Verzenio.
Written by: Jamie DePolo, senior editor
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