What is Afinitor® ? (everolimus)

Afinitor® (everolimus) is a kinase inhibitor used in combination with a medication called Aromasin® (exemestane) to treat advanced breast cancer that is hormone receptor positive (HR+) and human epidermal growth factor receptor 2 negative (HER2-) in postmenopausal women who have previously had treatment with Femara® (letrozole) or Arimidex® (anastrozole) and cancer progressed. Everolimus is manufactured by Novartis Pharmaceuticals.1

What is the active ingredient in Afinitor?

The active ingredient in Afinitor is everolimus, an inhibitor of the mammalian target of rapamycin (mTOR) pathway.2

How does everolimus work?

Everolimus blocks the mTOR pathway. Up to 70% of breast cancers have mutations on the mTOR pathway, which can fuel cancer growth. Everolimus is given in combination with Aromasin to delay or slow the growth of breast cancer cells in two ways: Aromasin helps block estrogen and everolimus helps block the mTOR pathway.1

What are some of the possible side effects of everolimus?

Everolimus can cause serious side effects, including1,2:

  • Breathing problems, such as an inflammation of the lungs called pneumonitis that can cause difficulty breathing and may lead to death
  • Infections, including serious infections such as pneumonia or a bacterial, fungal, or viral infection
  • Serious allergic reactions, which can cause hives, itching, rash, difficulty breathing or swallowing, chest pain, or dizziness
  • Angioedema, an allergic reaction that causes swelling of the tongue, mouth or throat and can cause difficulty breathing in people taking an ACE inhibitor (a medication for high blood pressure)
  • Kidney failure
  • Delayed wound healing
  • Increased sugar and fat in the blood
  • Decreased blood counts

The most common side effects of everolimus include1,2:

  • Mouth ulcers and sores
  • Infections
  • Diarrhea
  • Swelling in the arms, hands, feet, ankles, or face
  • Fatigue
  • Rash
  • Cough
  • Nausea
  • Fever
  • Decreased appetite
  • Abdominal pain
  • Headache

This is not an exhaustive list of all potential side effects of everolimus. Patients should talk to their doctor about what to expect with treatment with everolimus.

Things to know about everolimus

Before starting treatment with everolimus, patients should talk to their doctor about all their medications (prescription and over-the-counter), herbal supplements, and vitamins they are taking. Some medications or supplements may interfere with each other and may cause serious side effects. In particular, patients taking any of the following should mention them to their doctor1,2:

  • St. John’s wort
  • Any medications that weaken the immune system
  • Any medications for fungal or bacterial infections
  • Medications for tuberculosis
  • Seizure medication
  • HIV-AIDS medications
  • Medications for heart conditions or high blood pressure

Before starting treatment with everolimus, patients should discuss with their doctor all their medical conditions, especially1,2:

  • Current or previous kidney problems
  • Current or previous liver problems
  • Diabetes
  • High blood cholesterol
  • Any infections
  • Previous infections of hepatitis B
  • If patients are pregnant or could become pregnant, or have a partner who could become pregnant
  • If patients are breastfeeding or planning to breastfeed
  • Recent or planned surgery
  • Any unhealed wounds

People receiving everolimus should not receive live vaccinations or be around others who have recently received a live vaccine. Talk to your doctor if you are scheduled to get any vaccinations, or if you are unsure about any vaccines.1

Everolimus can cause harm to an unborn fetus and should not be used in pregnant women. Women who can become pregnant are advised to use effective contraception while taking everolimus and for at least eight weeks after stopping treatment (patients should discuss appropriate birth control methods with their doctor).2

It is not known if everolimus passes through breastmilk. Women should not breastfeed while taking everolimus and for at least two weeks after treatment is finished.2

Receiving everolimus

Your healthcare provider will determine the appropriate everolimus dosage and administration schedule for you. It is important to follow this schedule exactly as instructed, and not to stop taking everolimus or any accompanying medications on your own, unless you are instructed to do so by your healthcare provider.2

Patients should take their medication as prescribed by their doctor. Patients should talk to their doctor if they have any questions, or if they have questions regarding their everolimus regimen.

For more information, read the full prescribing information of everolimus.

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Written by: Emily Downward | Last reviewed: October 2020.