Afinitor: 7 things you should know

Medically reviewed by Carmen Pope, BPharm. Last updated on March 27, 2023.

1. How it works

• Afinitor is a brand (trade) name for everolimus which is a targeted medicine that may be used to treat various cancers.
• Afinitor is called an mTOR inhibitor. mTOR stands for mammalian target of rapamycin, and it is a type of protein in the body called a kinase that helps both healthy cells and cancerous cells get the energy they need. Sometimes kinases become overactive and help certain cancers to grow. Afinitor binds to a specific protein called FKBP-12 and forms a complex that inhibits the activity of mTOR, reducing cell proliferation, the formation of new blood vessels, and glucose uptake. Afinitor reduces the blood supply to cancer which slows down the growth and spread of cancer in the body.
• Afinitor belongs to the class of medicines known as mTOR inhibitors. It may also be called a selective immunosuppressant or a targeted treatment.

2. Upsides

• Afinitor may be used in combination with exemestane to treat postmenopausal women with advanced hormone receptor-positive, HER2-negative breast cancer after treatment with letrozole or anastrozole has failed.
• May be used to treat adults with neuroendocrine tumors that are unresectable, locally advanced, or that have metastasized; specifically progressive neuroendocrine tumors of pancreatic origin (PNET) or progressive, well-differentiated, nonfunctional NET of gastrointestinal (GI) or lung origin.
• Afinitor may be used to treat advanced renal cell carcinoma (RCC) in adults that have failed treatment with sunitinib or sorafenib.
• May also be used to treat certain conditions associated with tuberous sclerosis complex (TSC) which is a rare multisystem autosomal dominant genetic disease that causes non-cancerous tumors to grow in the brain and on other vital organs such as the kidneys, heart, liver, eyes, lungs, and skin. Afinitor may be used to treat TSC-associated renal angiomyolipoma in adults not requiring immediate surgery and TSC-associated subependymal giant cell astrocytoma (SEGA) that cannot be cured surgically in adults and children aged 1 year and older.
• A dispersable form of Afinitor, called Afinitor Disperz is available that may be used to prepare suspensions of Afinitor for children. Afinitor Disperz may be used for the treatment of TSC-associated SEGA and also for adults and children and pediatric patients aged 2 years and older with TSC-associated partial-onset seizures.
• Afinitor is taken orally, once a day. The usual dosage for most indications is 10mg once a day. For some conditions associated with TSC, the dosage depends on body weight. Therapeutic drug monitoring may be required for some forms of TSC.
• Afinitor is intended as a long-term treatment that is usually taken every day for as long as it is working or until unacceptable side effects occur.
• Afinitor is expensive but copay assistance and support are available through the Afinitor Novartis Universal Co-Pay Card which may help cover the costs of Afinitor for some people.
• A generic version of Afinitor is available, under the name of everolimus.

3. Downsides

If you are between the ages of 18 and 60, take no other medication or have no other medical conditions, side effects you are more likely to experience include:

• Stomatitis (an inflamed and sore mouth), infections, diarrhea, nausea, vomiting, constipation, fatigue, edema, dry mouth, lack of energy, fever, weight loss, decreased appetite, weight loss, high blood sugar levels, taste distortion, cough, and rash are the most common side effects. Other side effects may include anemia, dry skin, itching, a skin rash, high cholesterol, nose bleeds, shortness of breath, swollen hands or feet, insomnia, high blood pressure, indigestion, aching or painful joints, hot flushes, and hair loss.
• Afinitor is associated with some serious side effects that may require a dosage reduction or treatment discontinuation. These include pneumonitis (inflammation of the lungs), stomatitis (inflammation of the mouth and lips), metabolic events (such as high blood sugar or high cholesterol), thrombocytopenia (low blood platelet counts), and neutropenia (low neutrophils). Monitor for the development of these.
• Stomatitis occurs in 44% to 78% of people in clinical trials; grade 3-4 stomatitis was reported in 4% to 9%. Typically occurs within the first 8 weeks of treatment.
• Non-infectious pneumonitis has been reported in up to 19% of patients treated with Afinitor, sometimes in conjunction with pulmonary hypertension (including pulmonary arterial hypertension) as a secondary event. Fatal outcomes have been observed.
• Afinitor suppresses the immune system and may increase a person's risk of bacterial, fungal, viral, or protozoal infections, including infections with opportunistic pathogens. Test for hepatitis B before Afinitor administration.
• Has been associated with renal failure (including acute renal failure), and some cases were fatal. Elevations of serum creatinine and proteinuria have been reported and renal function should be monitored before starting Afinitor and 6-12 months thereafter.
• Severe hypersensitivity reactions have been reported with Afinitor/, including anaphylaxis, dyspnea, flushing, chest pain, and angioedema. Permanently discontinue Afinitor if hypersensitivity develops.
• Afinitor has been associated with elevations in cholesterol, triglycerides, and blood sugars. Monitor fasting lipid profiles before the start of therapy and periodically thereafter. If high, achieve control before starting Afinitor.
• Anemia, lymphopenia, neutropenia, and thrombocytopenia have all occurred. Monitor patients regularly.
• Afinitor is expensive and costs $15,680 to $16,407 for a supply of 28 tablets (one month). This works out to be $586 per tablet for the 5mg, 7.5mg, and 10mg strength tablets, and $560 for the 2.5mg strength tablet. However, most people will not have to pay this much because insurance plans should cover most of the cost of this medicine, although it is not covered by Medicare.
• Afinitor is not recommended for people with functional carcinoid tumors.
• Afinitor may delay wound healing and should be withheld at least 1 week before elective surgery. Do not administer for at least 2 weeks following major surgery and until the wound has healed adequately.
• People over the age of 65 may be at increased risk of adverse effects. In one trial, the incidence of deaths due to any cause within 28 days of the last Afinitor dose was 6% in patients ≥ 65 years of age compared to 2% in patients < 65 years of age. Adverse reactions leading to permanent treatment discontinuation were twice as likely to occur in those over 65 years compared with younger patients.
• Do not combine Afinitor and Afinitor Disperz to achieve the total dose.
• The dosage of Afinitor will need to be modified in people with liver disease or taking P-glycoprotein (P-gp) and CYP3A4 inhibitors or inducers.

Note: In general, seniors or children, people with certain medical conditions (such as liver or kidney problems, heart disease, diabetes, seizures) or people who take other medications are more at risk of developing a wider range of side effects. View complete list of side effects

4. Bottom Line

Afinitor (everolimus) is a targeted medicine that may be used to treat various cancers and TSC-associated conditions. It reduces the blood supply to the cancers which slows down their growth and spread. Stomatitis is a common side effect and Afinitor has been associated with serious and sometimes fatal pneumonitis, infections, and acute renal failure.

5. Tips

• Before you start Afinitor, your doctor will run some blood tests, which will be repeated periodically while you are taking Afinitor. These check the levels of certain blood cells and other substances in the blood and also check how well your liver and kidneys are working.
• Afinitor may be taken either with or without food. It should be taken at approximately the same time each day. If you miss a dose of Afinitor, and less than six hours have passed from the time you usually take it, then take it. If more than 6 hours have passed, skip that dose and take Afinitor, as usual, the next day.
• There are two different dosage forms of Afinitor: Afinitor and Afinitor Disperz. The difference between them is that Afinitor Disperz can be added to water to form a suspension that you can drink, whereas Afinitor is a tablet you swallow. Do not combine Afinitor and Afinitor Disperz to get the total dose.
• Swallow Afinitor tablets whole with a glass of water.
• Afinitor can cause an inflamed mouth and mouth ulcers (called stomatitis). When starting Afinitor, the incidence and severity may be reduced by using a dexamethasone alcohol-free oral solution as a swish and spit mouthwash. Ask your doctor about this. If stomatitis does occur, mouthwashes or other topical treatments may help but avoid products containing alcohol, hydrogen peroxide, iodine, or thyme, as they may exacerbate stomatitis. Do not administer antifungal agents, unless a fungal infection has been diagnosed.
• Always talk to your doctor or pharmacist before taking any other medications with Afinitor including supplements or herbals or medicines brought from a supermarket or drug store. Afinitor interacts with many drugs and also grapefruit products. Avoid ingesting grapefruit and grapefruit juice.
• Caregivers who are preparing Afinitor Disperz tablets for another person should wear gloves to avoid possible contact with Afinitor. Use either an oral syringe or a small drinking glass.
• If using an oral syringe, place the prescribed dose into a 10-mL syringe and add one 10mg tablet. If higher doses are required, prepare an additional syringe. Do not break or crush tablets. Draw approximately 5 mL of water and 4 mL of air into the syringe. Place the filled syringe into a container (tip-up) for 3 minutes, until the tablets are in suspension. Gently invert the syringe 5 times immediately before administration. After administration of the prepared suspension, refill the syringe with 5 mL of water and 4 mL of air, and swirl the contents to suspend the remaining particles. Administer the entire contents of the syringe.
• If using a small drinking glass, place a 10mg tablet into the glass containing approximately 25 mL of water. If higher doses are required, prepare an additional glass. Do not break or crush tablets. Allow 3 minutes for a suspension to occur. Stir the contents gently with a spoon, immediately before drinking. After administration of the prepared suspension, add 25 mL of water and stir with the same spoon to re-suspend the remaining particles. Administer the entire contents of the glass.
• Administer the suspension immediately after preparing it. If not used within 60 minutes, throw it away. prepare in water only.
• Tell your doctor immediately if you experience any new or worrying symptoms such as a new or worsening cough, shortness of breath, chest pain, difficulty breathing, or wheezing.
• While you are taking Afinitor you are at an increased risk of infections, because Afinitor lowers your immune response. Some vaccinations may need to be avoided during treatment with Afinitor. See your doctor immediately if you develop any signs of an infection which may include fever, pain, swelling, redness, or a discharge. Your doctor may test you for the presence of infections (such as hepatitis B) before Afinitor initiation. Afinitor can delay wound healing and should be stopped one week before surgery.
• Afinitor may harm a developing baby and women should not become pregnant while receiving Afinitor and for eight weeks after the last dose. Female partners of males using Afinitor should use adequate and effective contraception to ensure pregnancy does not happen while they are taking Afinitor and for at least 4 weeks after the final dose (if they are of childbearing age). Afinitor may affect long-term fertility. Breastfeeding should not happen in women who are taking Afinitor and for two weeks after the last dose. Afinitor may also prevent menstruation and women may miss 1 or more menstrual periods. Tell your healthcare provider if this happens.
• Store Afinitor tablets at room temperature, 20°-25°C (68°-77°F); excursions permitted between 15°C and 30°C (59°F and 86°F).

6. Response and effectiveness

• Afinitor is usually taken every day for as long as it is working or until unacceptable side effects occur. It is meant to be taken as a long-term treatment. In clinical trials, the average duration of treatment was approximately 24.0 weeks (ranging from one week to almost 200 weeks).
• In the Bolero-2 study, women who were assigned Afinitor in combination with exemestane (Aromasin) were more likely to experience a complete response (3/485) or a partial response (58/485) compared to those who were assigned a placebo (no complete responses and only 4/239 partial responses). There was no difference in overall survival rate in those assigned Afinitor combined with exemestane compared with those assigned placebo and exemestane after 39.3 months (just over 3 years).
• A significant difference in progression-free survival was reported for Afinitor for pancreatic neuroendocrine tumors and neuroendocrine tumors of gastrointestinal or lung origin.
• Trials have shown that the growth of estrogen-dependent and HER2+ breast cancer cells are inhibited by the effects of Afinitor. Combination treatment with other agents such as exemestane (Aromasin) for breast cancer enhances its effects.

7. Interactions

Medicines that interact with Afinitor may either decrease its effect, affect how long it works, increase side effects, or have less of an effect when taken with Afinitor. An interaction between two medications does not always mean that you must stop taking one of the medications; however, sometimes it does. Speak to your doctor about how drug interactions should be managed.

There are over 400 medications that have major or moderate interactions with Afinitor. Some common medications that may interact with Afinitor include:

• ACE inhibitors, such as captopril, enalapril, or quinapril (may cause angioedema)
• antibiotics, such as amikacin, clarithromycin, erythromycin, or gentamicin
• anticancer treatments, such as ceritinib, cisplatin, or nilotinib
• antidepressants, such as fluoxetine
• antidiabetic medications, such as insulin, glyburide, glipizide, or glimepiride
• antifungals such as amphotericin B, fluconazole, itraconazole, or ketoconazole
• antiseizure medications, such as carbamazepine or fosphenytoin
• antivirals, such as acyclovir
• aprepitant
• corticosteroids, such as dexamethasone
• CYP3A4 inducers such as phenobarbital, phenytoin, rifampicin, St. John's Wort, or glucocorticoids (dosage increase needed)
• cyclosporin
• dabigatran
• heart medications, such as amiodarone, or diltiazem
• herbals, such as cannabidiol
• HIV medications, such as atazanivir, cobicistat, or saquinavir
• lactobacillus
• leflunomide
• lithium
• methotrexate
• midazolam
• mifepristone
• moderate or strong CYP3A4 inhibitors such as clarithromycin, erythromycin, diltiazem, itraconazole, ketoconazole, ritonavir, verapamil, goldenseal, and grapefruit products (dosage reduction needed)
• multiple sclerosis agents such as fingolimod or ozanimod
• NSAIDs such as celecoxib, diclofenac, or ibuprofen
• octreotide
• remdesivir
• rifampin or rifabutin
• TNF inhibitors, such as adalimumab, etanercept, or infliximab
• vaccines, such as the BCG vaccine, human papillomavirus vaccine, or influenza vaccine
• zarfirlukast.

Note that this list is not all-inclusive and includes only common medications that may interact with Afinitor. You should refer to the prescribing information for Afinitor for a complete list of interactions.

References

• Afinitor (everolimus) [Package insert]. Updated 03/2023. Novartis Pharmaceuticals Corporation. https://www.drugs.com/pro/afinitor.html
• Everolimus Cancer Research UK. https://www.cancerresearchuk.org/about-cancer/cancer-in-general/treatment/cancer-drugs/drugs/everolimus

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use Afinitor only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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