Osimertinib is used to treat non-small cell lung cancer that is positive for an abnormal "EGFR" gene. You doctor will test you for this gene.

Osimertinib is sometimes given when the cancer has spread to other parts of the body (metastatic), or may come back after surgery.

Osimertinib may also be used for purposes not listed in this medication guide.

Osimertinib can cause serious side effects on your heart, lungs, skin, or eyes.

Call your doctor at once if you have fast or pounding heartbeats, swelling in your lower legs, fever, cough, trouble breathing, skin blistering or peeling, vision changes, eye pain, increased sensitivity to light, or if you feel light-headed or short of breath.

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

Osimertinib is usually given once per day, with or without food.

To make swallowing easier, you may place the tablet in a glass with about 2 ounces of water. Stir until the tablet is mostly dissolved and drink this mixture right away. Add 4 to 8 ounces more water to the glass, swirl gently and drink right away.

You may need medical tests to check your heart function.

Store at room temperature away from moisture and heat.

Usual Adult Dose for Non-Small Cell Lung Cancer:

80 mg orally once a day
Duration of therapy:
-Adjuvant setting: Until disease progression, unacceptable toxicity, or for up to 3 years
Metastatic lung cancer: Until disease progression or unacceptable toxicity

Uses:
-As adjuvant therapy after tumor resection in patients with non-small cell lung cancer (NSCLC) whose tumors have epidermal growth factor receptor (EGFR) exon 19 deletions or exon 21 L858R mutations, as detected by an FDA-approved test
-For first-line treatment of patients with metastatic NSCLC whose tumors have EGFR exon 19 deletions or exon 21 L858R mutations, as detected by an FDA-approved test
-For treatment of adult patients with metastatic EGFR T790M mutation-positive NSCLC, as detected by an FDA-approved test, whose disease has progressed on or after EGFR tyrosine kinase inhibitor (TKI) therapy

You should not use osimertinib if you are allergic to it.

Tell your doctor if you have ever had:

• lung or breathing problems;

• an electrolyte imbalance (such as high or low blood levels of sodium, calcium, potassium, or magnesium);

• eye problems; or

• heart problems, including long QT syndrome (in you or a family member).

Osimertinib can harm an unborn baby if the mother or the father is using osimertinib.

• If you are a woman, you may need a pregnancy test to make sure you are not pregnant. Use birth control while using this medicine and for at least 6 weeks after your last dose.

• If you are a man, use birth control if your sex partner is able to get pregnant. Keep using birth control for at least 4 months after your last dose.

• Tell your doctor right away if a pregnancy occurs.

Pregnancy may be less likely to occur while the mother or the father is using this medicine. Both men and women should still use birth control to prevent pregnancy because the medicine can harm an unborn baby.

Do not breastfeed while using this medicine, and for at least 2 weeks after your last dose.

Skip the missed dose and use your next dose at the regular time. Do not use two doses at one time.

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

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom).

It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach. http://www.upandaway.org

Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA's Safe Disposal of Medicines website (http://goo.gl/c4Rm4p) for more information if you do not have access to a take-back program.

Unless your doctor tells you otherwise, continue your normal diet.

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

Get emergency medical help if you have signs of an allergic reaction (hives, difficult breathing, swelling in your face or throat) or a severe skin reaction (fever, sore throat, burning eyes, skin pain, red or purple skin rash with blistering and peeling).

Osimertinib may cause serious side effects. Call your doctor at once if you have:

• skin redness or purple spots that don't turn pale when pressed, and that still look red or bruised after 24 hours (may appear on your arms, legs, buttocks, or midsection);

• redness, rash, or blisters on the palms of your hands or the soles of your feet;

• new or worsening cough or trouble breathing;

• fast or pounding heartbeats;

• swelling in your lower legs, weight gain, feeling short of breath;

• a light-headed feeling, like you might pass out;

• low blood cell counts--fever, chills, tiredness, mouth sores, skin sores, easy bruising, unusual bleeding, pale skin, cold hands and feet; or

• eye problems--vision changes, watery eyes, increased sensitivity to light, eye pain or redness.

Your cancer treatments may be delayed or permanently discontinued if you have certain side effects.

Common side effects of osimertinib may include:

• low blood cell counts;

• muscle, bone, or joint pain;

• diarrhea;

• tiredness;

• cough, mouth sores;

• dry skin, rash; or

• redness, tenderness, pain, or other problems with your fingernails or toenails.

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.

Osimertinib can cause a serious heart problem. Your risk may be higher if you also use certain other medicines for infections, asthma, heart problems, high blood pressure, depression, mental illness, cancer, malaria, or HIV.

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

Keep all appointments with your doctor and the laboratory. Your doctor will order certain heart function tests before and during your treatment to be sure it is safe for you to take osimertinib, and to check your body's response to the medication. Your doctor may also order a lab test before you begin your treatment to find out if your cancer can be treated with osimertinib.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.