Tazemetostat is used to treat advanced epithelioid sarcoma, a rare slow-growing type of soft tissue cancer. tazemetostat is used when the cancer has spread to other parts of the body (metastatic) or cannot be removed with surgery.

Tazemetostat is for use in adults and children at least 16 years old.

Tazemetostat was approved by the US Food and Drug Administration (FDA) on an "accelerated" basis. In clinical studies, some people responded to this medicine, but further studies are needed.

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

Using tazemetostat may increase your risk of developing bone marrow disorders or other cancers. Tell your doctor if you feel unusually tired or have a fever, pale skin, easy bruising, or bone pain.

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

You may take tazemetostat with or without food.

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

If you vomit shortly after taking tazemetostat, do not take another dose. Wait until your next scheduled dose time to take the medicine again.

Store at room temperature away from moisture and heat. Keep the tablets in their original container, along with the packet or canister of moisture-absorbing preservative.

Usual Adult Dose for Soft Tissue Sarcoma:

800 mg orally twice daily

Duration: Until disease progression or unacceptable toxicity.

Uses:
For the treatment of adult patients with, metastatic or locally advanced epithelioid sarcoma not eligible for complete resection

Usual Adult Dose for Follicular Lymphoma:

800 mg orally twice daily

Duration: Until disease progression or unacceptable toxicity.

Comment:
Select patients with relapsed or refractory (R/R) follicular lymphoma (FL) based on the presence of EZH2 mutation.

Uses:
For the treatment of adult patients with, relapsed or refractory follicular lymphoma whose tumors are positive for an EZH2 mutation and who have received at least 2 prior systemic therapies or who have no satisfactory alternative treatment options

Usual Pediatric Dose for Soft Tissue Sarcoma:

16 years and older:
800 mg orally twice daily

Duration: Until disease progression or unacceptable toxicity.

Use: For the treatment of pediatric patients aged 16 years and older with metastatic or locally advanced epithelioid sarcoma not eligible for complete resection

Using tazemetostat may increase your risk of developing bone marrow disorders or other cancers, such as leukemia or lymphoma. Ask your doctor about this risk.

You may need to have a negative pregnancy test before starting this treatment.

Tazemetostat can harm an unborn baby or cause birth defects if the mother or the father is using tazemetostat.

• If you are a woman, do not use tazemetostat if you are pregnant. Use effective nonhormonal birth control to prevent pregnancy while you are using this medicine and for at least 6 months after your last dose.

• If you are a man, use effective birth control if your sex partner is able to get pregnant. Keep using birth control for at least 6 months after your last dose.

Tazemetostat can make hormonal birth control less effective, including birth control pills, injections, implants, skin patches, and vaginal rings. To prevent pregnancy while using tazemetostat, use a barrier form of birth control: condom, diaphragm, cervical cap, or contraceptive sponge.

Do not breastfeed while using this medicine, and for at least 1 week 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.

Do not eat large amounts of grapefruit or drink grapefruit juice while taking this medication.

Grapefruit may interact with tazemetostat and lead to unwanted side effects. Avoid the use of grapefruit products.

Avoid taking an herbal supplement containing St. John's wort.

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

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

• unusual tiredness;

• bone pain; or

• low blood cell counts--fever, chills, tiredness, mouth sores, skin sores, easy bruising, unusual bleeding, pale skin, cold hands and feet, feeling light-headed or short of breath.

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

Common side effects of tazemetostat may include:

• nausea, vomiting, loss of appetite;

• constipation;

• pain; or

• tiredness.

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.

Sometimes it is not safe to use certain medications at the same time. Some drugs can affect your blood levels of other drugs you take, which may increase side effects or make the medications less effective.

Other drugs may affect tazemetostat, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.

Keep all appointments with your doctor and the laboratory. For some conditions, your doctor will order a lab test before you begin your treatment to see whether your cancer can be treated with tazemetostat. Your doctor may also order certain lab tests to check your body's response to tazemetostat.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

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.