Everolimus (Afinitor) is a type of targeted therapy called an mTOR inhibitor, or a mammalian target of rapamycin inhibitor. It stops cancer cells from dividing and may block the growth of new blood vessels that tumors need to grow. Everolimus was the first mTOR inhibitor approved for treating metastatic breast cancer.

How everolimus works

mTOR is a protein kinase, a type of enzyme that helps control cell growth. In some cancers, mTOR-activated proteins work abnormally and encourage cancer cells to grow and spread. mTOR also directs nutrients to the cancer cells, helping to support them.

Everolimus works to slow or stop mTOR’s role in the growth of cancer cells. Paired with aromatase inhibitors like exemestane (Aromasin), everolimus slows cell growth by blocking nutrients and directions from mTOR, as well as the estrogen that encourages growth.

Who gets everolimus

Everolimus is FDA approved for use with exemestane in postmenopausal women with metastatic, hormone receptor-positive, HER2-negative breast cancer that grows after treatment with aromatase inhibitors alone.

How everolimus is given

Everolimus is a pill you can take by mouth once a day. You usually need to take it at the same time each day. Your doctor will recommend a specific dosage.

Side effects and things to remember

Everolimus is an effective treatment but it has some possible serious side effects. When choosing treatments a treatment, you and your doctors should discuss how you can keep your quality of life high while you manage the disease.

Common side effects may include:

Less common side effects may include:

Before starting everolimus, be sure to tell your doctor about any medicines you are taking, including vitamins, herbal supplements and over the counter medicines.

You should avoid becoming pregnant while you are receiving everolimus. Tell your doctor right away if you become pregnant or may be pregnant while you are undergoing treatment.

Your doctor, pharmacist or nurse can help you manage your side effects. You can also go to our section on Side Effects for more information.



Reviewed and updated: August 31, 2015

Reviewed by: Kanu Sharan MD


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Living Beyond Breast Cancer is a national nonprofit organization that seeks to create a world that understands there is more than one way to have breast cancer. To fulfill its mission of providing trusted information and a community of support to those impacted by the disease, Living Beyond Breast Cancer offers on-demand emotional, practical, and evidence-based content. For over 30 years, the organization has remained committed to creating a culture of acceptance — where sharing the diversity of the lived experience of breast cancer fosters self-advocacy and hope. For more information, learn more about our programs and services.