Imlunestrant

Imlunestrant is used in adults to treat specific types of breast cancer that are advanced or have spread to other parts of the body (metastatic) after other treatments did not work or have stopped working.

Imlunestrant may be used by itself or along with other treatments.

Your doctor will ensure that you have the right tumor type to be treated with imlunestrant.

Imlunestrant may also be used for reasons not mentioned in this medication guide.

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

Your doctor will perform tests to make sure imlunestrant is the right treatment for you.

Do not change your dose or stop taking this medicine without your doctor's advice.

Imlunestrant is usually taken once per day, at the same time each day.

Take on an empty stomach, at least 2 hours before or 1 hour after a meal.

Swallow the tablet whole and do not crush, chew, or break it.

If you vomit shortly after taking imlunestrant, do not take another dose. Take your next dose as scheduled.

You will need frequent blood tests before and during treatment with imlunestrant.

Store at room temperature away from moisture and heat.

Read and carefully follow the instructions provided with this medicine about how to safely dispose of any unused portion.

Use only as directed. Inform your doctor if you are taking other medicines or have other medical conditions or allergies.

Tell your doctor if you have or have ever had:

• high cholesterol or triglycerides; or
• liver disease.

Imlunestrant can harm an unborn baby if the mother or the father is using imlunestrant.

• If you are a woman, you may need a pregnancy test to ensure you are not pregnant. Use birth control while using this medicine and for at least 1 week after your last dose.
• If you are a man, use birth control if your sex partner can get pregnant. Keep using birth control while using this medicine and for at least 1 week after your last dose.
• Tell your doctor right away if you become pregnant.

Do not breastfeed while using this medicine, and for at least 1 week after your last dose.

Imlunestrant may affect fertility in men and women. It could be harder to achieve pregnancy while either parent is using this medicine.

Get emergency medical help if you have signs of an allergic reaction: hives, difficulty breathing, swelling of your face, lips, tongue, or throat.

Imlunestrant may cause serious side effects. Call your doctor right away if you have:

• fluid build-up in or around the lungs--pain when you breathe, feeling short of breath while lying down, wheezing, gasping for breath, cough with foamy mucus, cold and clammy skin, anxiety, rapid heartbeats;
• heart attack symptoms--chest pain or pressure, pain spreading to your jaw or shoulder, nausea, sweating;
• heart problems--swelling, rapid weight gain, feeling short of breath, slow heart rate, weak pulse, fainting, slow breathing (breathing may stop), low blood pressure, confusion, severe drowsiness;
• stomach bleeding--bloody or tarry stools, coughing up blood or vomit that looks like coffee grounds; or
• liver problems--loss of appetite, nausea, vomiting, stomach pain (upper right side), tiredness, itching, dark urine, clay-colored stools, jaundice (yellowing of the skin or eyes).

Your cancer treatments may change, be delayed, or permanently stopped if you have certain side effects.

Common side effects of imlunestrant may include:

• muscle and joint pain;
• nausea, constipation, diarrhea, stomach pain;
• tiredness;
• high cholesterol or triglycerides; or
• abnormal blood tests.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Usual Adult Dose for Breast Cancer:

400 mg orally once a dayDuration of therapy: Until disease progression or unacceptable toxicityComments:-This drug is recommended in patients who have an estrogen receptor-1 (ESR1) mutation detected in a plasma specimen using a US FDA-approved test.-Pre- or perimenopausal adults should receive a gonadotropin-releasing hormone agonist according to current clinical practice standards. Use: For the treatment of patients with estrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative, ESR1-mutated advanced or metastatic breast cancer with disease progression following at least one line of endocrine therapy

Take the medicine as soon as you can, but if you are 6 or more hours late for the dose, skip the missed dose and take your next dose at the regular time. Do not take two doses at one time.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Follow your doctor's instructions about any restrictions on food, beverages, or activity.

Sometimes it is not safe to use certain medicines together. Some drugs can change the levels of other drugs in your blood, which may increase side effects or make the medicines less effective.

Other drugs may affect imlunestrant, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all other medicines you are using.