Lytgobi (futibatinib) belongs to a class of medications called kinase inhibitors. Futibatinib works by blocking the action of the abnormal protein that signals cancer cells to multiply. This helps slow or stop the spread of cancer cells.

Lytgobi is used in adults to treat bile duct cancer (cholangiocarcinoma) that has spread (metastatic) or cannot be removed by surgery:

• who have already received another treatment; and

• whose tumor has an abnormal "FGFR2" gene.

Your doctor will make sure you have the correct tumor type to be treated with Lytgobi.

You should not use Lytgobi if you are allergic to futibatinib, any other medications, or any of the ingredients in Lytgobi tablets.

Tell your doctor and pharmacist what prescription and non-prescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take while taking Lytgobi. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.

Tell your doctor if you have diabetes, anemia, history of bleeding disorder, or if you have or ever had kidney or liver problems.

Use only as directed. Tell your doctor if you use other medicines or have other medical conditions or allergies.

Take Lytgobi exactly as prescribed by your doctor Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose.

You may take Lytgobi once a day with or without food at about the same time.

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

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

Your treatment with Lytgobi may be dealyed or permanently discontinued if you have certain side effects.

You will need to see an eye specialist before you start using Lytgobi, every 2 months for the first 6 months, and then every 3 months thereafter while you are using this medicine.

You may need to follow a special diet. Follow all instructions of your doctor or dietitian. Learn about the foods you should eat or avoid.

Your blood will need to be tested during treatment with Lytgobi.

You should use artificial tears, or lubricating eye gels during treatment with Lytgobi.

Store at room temperature away from moisture and heat.

Usual Adult Dose for Cholangiocarcinoma of biliary tract:

Usual dose: 20 mg (five 4 mg tablets) taken orally once daily

Comments:
-Confirm the presence of an FGFR2 gene fusion or other rearrangement prior to initiation of treatment.
-Treatment to be continued until disease progression or unacceptable toxicity occurs.

Use: Patients with previously treated, unresectable, locally advanced or metastatic intrahepatic cholangiocarcinoma harboring fibroblast growth factor receptor 2 (FGFR2) gene fusions or other rearrangements.

To make sure Lytgobi is safe for you, tell your doctor if you have:

• vision or eye problems.

Futibatinib can harm an unborn baby if the mother or the father is using this medicine.

• 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 1 week 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 1 week after your last dose.

• Tell your doctor right away if a pregnancy occurs.

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

Use the medicine as soon as you can, but skip the missed dose if you are more than 12 hours late for the dose. Do not use two doses at one time.

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

Grapefruit may interact with futibatinib and cause side effects. Avoid consuming grapefruit products.

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

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

• changes in your vision, including blurred vision, seeing flashes of light, or black spots;

• muscle cramps; or

• numbness or tingling feeling around your mouth.

Common Lytgobi side effects may include:

• stomach pain, nausea, vomiting, constipation, diarrhea, loss of appetite;

• dry mouth, skin, or eye;

• pain and burning when you urinate;

• tiredness or weakness;

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

• muscle or joint pain;

• changes in your sense of taste;

• change in appearance or color of nails;

• hair loss;

• abnormal lab tests;

• high blood sugar - increased thirst, increased urination, dry mouth, fruity breath odor;

• low blood sugar - headache, hunger, sweating, irritability, dizziness, fast heart rate, and feeling anxious or shaky;

• low blood potassium - leg cramps, constipation, irregular heartbeats, fluttering in your chest, increased thirst or urination, numbness or tingling, muscle weakness or limp feeling;

• high calcium levels - confusion, tiredness, nausea, vomiting, loss of appetite, constipation, increased thirst or urination, weight loss;

• low blood sodium - headache, confusion, problems with thinking or memory, weakness, feeling unsteady; 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.

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.

Tell your doctor about all your other medicines, especially:

• itraconazole; or

• rifampin.

This list is not complete. Other drugs may interact with futibatinib, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.