Momelotinib is used to treat adults with specific types of myelofibrosis who have anemia.

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

Tell your doctor if you have or have ever had:

• an infection;
• a heart attack, other heart problems, or stroke;
• a blood clot;
• any other cancer;
• if you take medicine to treat rheumatoid arthritis;
• if you smoke or were a smoker in the past;
• hepatitis B; or
• liver disease.

May harm an unborn baby. Use effective birth control while using momelotinib and for at least 1 week after your last dose. Tell your doctor if you become pregnant.

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

Use Momelotinib (Oral) exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or for longer than recommended.

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

Call your doctor at once if you have:

• signs of infection--fever, chills, sore throat, body aches, unusual tiredness, loss of appetite, bruising or bleeding;
• 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);
• heart attack symptoms--chest pain or pressure, pain spreading to your jaw or shoulder, nausea, sweating;
• signs of a stroke--sudden numbness or weakness (especially on one side of the body), severe headache, slurred speech, problems with vision or balance;
• signs of a blood clot in the lung--chest pain, sudden cough or shortness of breath, dizziness, coughing up blood;
• signs of a blood clot deep in the body--pain, swelling, or warmth in one leg; or
• unusual bleeding, bruising, black or tarry stools.

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

Common side effects may include:

• diarrhea, nausea;
• signs of infection;
• dizziness;
• tiredness; or
• easy bruising, unusual bleeding, purple or red spots under your skin.

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.

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