Erdafitinib is used in adults to treat bladder cancer that has spread to other parts of the body (metastatic), or cannot be removed with surgery.

Erdafitinib is used if your cancer has a specific genetic marker (an abnormal "FGFR" gene), and if you were treated with at least one other platinum cancer medicine that did not work or has stopped working. Your doctor will test you for this gene.

Erdafitinib is usually given after other treatments have failed.

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

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

Follow all directions on your medicine label and package. Tell each of your healthcare providers about all your medical conditions, allergies, and all medicines you use.

Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose. Use the medicine exactly as directed.

You may take erdafitinib whole once per day with or without food.

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

Your doctor may want you to use artificial tears or other lubricating eye medication every 2 hours while you are awake. Keep using these medicines for as long as your doctor has prescribed.

Your blood will need to be tested often. Your cancer treatments may be delayed or permanently discontinued if you have certain side effects.

You will need frequent vision tests.

Store at room temperature away from moisture and heat.

Usual Adult Dose for Urothelial Carcinoma:

8 mg orally once daily; increase to 9 mg orally once daily based on serum phosphate levels and tolerability at 14 to 21 days until disease progression or unacceptable toxicity

Comments
-Select patients for therapy based on the presence of susceptible FGFR genetic alterations in tumor specimens as detected by an FDA-approved companion diagnostic.

Use: For the treatment of adult patients with locally advanced or metastatic urothelial carcinoma (mUC), that has susceptible FGFR3 or FGFR2 genetic alterations, and progressed during or following at least one line of prior platinum-containing chemotherapy, including within 12 months of neoadjuvant or adjuvant platinum-containing chemotherapy.

Tell your doctor if you have ever had problems with your eyes or vision.

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

Both men and women using erdafitinib should use effective birth control to prevent pregnancy. Erdafitinib can harm an unborn baby or cause birth defects if the mother or father is using this medicine.

Keep using birth control for at least 1 month after your last dose. Tell your doctor right away if a pregnancy occurs while either the mother or the father is using erdafitinib.

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

It may be harder for you to get pregnant while you are using this medicine. You should still use birth control to prevent pregnancy because the medicine can harm an unborn baby.

Take the missed dose on the same day you remember it. Take your next dose at the regular time the next day. Do not use two doses in one day.

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.

Your doctor may instruct you to follow a low-phosphorus diet. Follow these directions carefully. Talk to your doctor about foods that contain high amounts of phosphorus.

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 of your face, lips, tongue, or throat.

You may have high phosphate levels, and your blood will need to be tested often. Tell your doctor if you have symptoms such as numbness or tingling around your mouth, muscle stiffness, body aches, itching or rash, tiredness, trouble sleeping, nausea, vomiting, loss of appetite, or feeling short of breath.

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

• vision problems, vision loss;

• eye pain or redness; or

• problems with your fingernails or toenails--pain, bleeding, separation of the nails from the skin (nail bed), unusual breakage, changes in nail color or texture, cracks or infection in your cuticles.

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

Common side effects of erdafitinib may include:

• dry eyes;

• dry mouth, mouth sores;

• hair loss;

• dry skin, problems with your fingernails or toenails;

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

• muscle pain;

• feeling tired;

• abnormal liver or kidney function tests;

• low sodium levels, low red blood cell count;

• nausea, stomach pain, loss of appetite;

• diarrhea, constipation; or

• changes in your sense of taste.

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 medicines at the same time. Some drugs can affect your blood levels of other drugs you use, which may increase side effects or make the medicines less effective.

Tell your doctor about all your other medicines, especially:

• medicines that may change phosphate levels--potassium phosphate supplements, vitamin D supplements, antacids, enemas or laxatives that contain phosphate, and other medicines known to contain phosphate.

Other drugs may affect erdafitinib, 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, eye doctor, and the laboratory. Your doctor will order certain lab tests to check your body's response to erdafitinib. Your doctor will order a lab test before you begin your treatment to see whether your cancer can be treated with erdafitinib.

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.