Vonjo is a prescription medicine used to treat adults with certain types of myelofibrosis who have a platelet count below 50 x 10⁹/L.

It is not known if this medicine is safe and effective in children.

• Take Vonjo exactly as your healthcare provider tells you to take it.
• Do not change your dose or stop treatment without first talking to your healthcare provider.
• If you take other kinase inhibitors, carefully follow your healthcare provider’s instructions about how to slowly decrease (taper) your dose or stop the other kinase inhibitor medicines before you begin taking Vonjo.
• Vonjo capsules are usually taken by mouth 2 times each day.
• Swallow the capsules whole. Do not open, break, or chew capsules.
• You can take the capsules with or without food.
• Take your doses at about the same time every day.
• If you notice any change in how often you have bowel movements, if they become softer or you have diarrhea, start taking an antidiarrheal medicine (for example, loperamide) as soon as you notice changes, as directed by your healthcare provider.
• If you take too much or overdose, call your healthcare provider or go to the nearest emergency room right away and take your bottle of Vonjo with you.
• If you miss a dose, skip the dose and just take your next dose at your regularly scheduled time. Do not take 2 doses at the same time to make up for the missed dose.
• Your healthcare provider will do blood tests before you start, and as needed during treatment.
• Your healthcare provider may change your dose or how often you take Vonjo, temporarily stop or permanently stop treatment if you have certain side effects.

Usual Adult Dose for Myelofibrosis

- 200 mg orally twice daily

- Use: treatment of adults with intermediate or high-risk primary or secondary (post-polycythemia vera or post-essential thrombocythemia) myelofibrosis with a platelet count below 50 × 10⁹ /L

Before you start treatment, tell your healthcare provider about all of your medical conditions, including if you:

• smoke or were a smoker in the past
• have had any other cancers. See Possible increased risk of new (secondary) cancers in the section Vonjo side effects.
• have had a blood clot, heart attack, other heart problems, or stroke
• have an infection. See Risk of infection in the section Vonjo side effects.
• have diarrhea or commonly have loose stools
• have nausea or vomiting
• have active bleeding, have had severe bleeding, or plan to have surgery. You should stop taking Vonjo 7 days before any planned surgery or invasive procedures (such as a heart catheterization, stent placement in a coronary artery in your heart, or a procedure for varicose veins). See Vonjo side effects.
• have liver or kidney problems
• are pregnant or plan to become pregnant. It is not known if Vonjo will harm your unborn baby
• are breastfeeding or plan to breastfeed. It is not known if Vonjo passes into your breast milk. You should not breastfeed during treatment and for 2 weeks after your last dose. Talk to your healthcare provider about the best way to feed your baby during this time.

Vonjo can cause serious side effects including:

• Bleeding. Vonjo may cause severe bleeding, which can be serious and in some cases may lead to death. Avoid taking Vonjo if you are bleeding. If you develop bleeding, stop treatment and call your healthcare provider. Your healthcare provider will do a blood test to check your blood cell counts before you start, and regularly during your treatment. Tell your healthcare provider right away if you develop any of these symptoms: unusual bleeding, bruising, and fever. You will need to stop taking Vonjo 7 days before any planned surgery or invasive procedure (such as a heart caterterization, stent placement in a coronary artery in your heart, or a procedure for varicose veins). Your healthcare provider should tell you when you can start taking Vonjo again.
• Diarrhea. Diarrhea is common with Vonjo, but can also be severe, and cause loss of too much body fluid (dehydration). Tell your healthcare provider if you have diarrhea and follow instructions for what to do to help treat diarrhea. Drink plenty of fluids to help prevent dehydration. Your healthcare provider may change your dose if you have severe diarrhea.
• Worsening low platelet counts. Your healthcare provider will do blood tests to check your blood counts before you start taking and during treatment.
• Changes in the electrical activity of your heart called QTc prolongation. QTc prolongation can cause irregular heartbeats that can be life-threatening. Your healthcare provider will check the electrical activity of your heart with a test called an electrocardiogram (ECG) before you start, and during treatment as needed. If you have a history of low blood potassium, it is important that you get your blood tests done as ordered by your healthcare provider to monitor your body salts (electrolytes) in your blood. Tell your healthcare provider right away if you feel dizzy, lightheaded, or faint.
• Increased risk of major cardiovascular events such as heart attack, stroke, or death in people who have cardiovascular risk factors and who are current or past smokers have happened in some people taking another JAK inhibitor to treat rheumatoid arthritis.
  Get emergency help right away if you have any symptoms of a heart attack or stroke while taking Vonjo, including:
  • discomfort in the center of your chest that lasts for more than a few minutes, or that goes away and comes back
  • severe tightness, pain, pressure, or heaviness in your chest, throat, neck, or jaw
  • pain or discomfort in your arms, back, neck, jaw, or stomach
  • shortness of breath with or without chest discomfort
  • breaking out in a cold sweat
  • nausea or vomiting
  • feeling lightheaded
  • weakness in one part or on one side of your body
  • slurred speech
• Increased risk of blood clots. Blood clots in the veins of your legs (deep vein thrombosis, DVT) or lungs (pulmonary embolism, PE) have happened in some people taking another JAK inhibitor, and may be life-threatening. Tell your healthcare provider if you have had blood clots in the veins of your legs or lungs in the past.
  Tell your healthcare provider right away if you have any signs and symptoms of blood clots during treatment including:
  • swelling, pain, or tenderness in one or both legs
  • sudden, unexplained chest pain
  • shortness of breath or difficulty breathing
• Possible increased risk of new (secondary) cancers. People who take another JAK inhibitor for rheumatoid arthritis have an increased risk of new (secondary) cancers, including lymphoma and other cancers, except non-melanoma skin cancer. The risk of new cancers is further increased in people who smoke or who smoked in the past.
• Risk of Infection. People who have certain blood cancers and take another JAK inhibitor have an increased risk of serious infections. Infections are common, but people who take Vonjo may also develop serious infections, including bacterial, mycobacterial, fungal, and viral infections. If you have a serious infection, your healthcare provider may not start you on Vonjo until your infection is gone. Your healthcare provider will monitor you and treat you for any infections that you get during treatment.
  Tell your healthcare provider right away if you develop any of the following symptoms of infection:
  • chills
  • aches
  • fever
  • nausea
  • vomiting
  • weakness
  • painful skin rash or blisters

The most common side effects include:

• nausea and vomiting
• low red blood cell count (anemia)
• swelling of your ankles, legs, and feet

Vonjo may affect fertility in males. You may have problems fathering a child. Talk to your healthcare provider if this is a concern for you.

These are not all of the possible side effects. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements. Taking Vonjo with certain other medicines may affect the amount of Vonjo in your blood, and may increase your risk of side effects or affect how well Vonjo works.

Know the medicines you take. Keep a list of the medicines you take to show your healthcare provider and pharmacist when you get a new medicine.

Especially tell your doctor of if you are taking any of the following medicines:

• macrolide antibiotics (clarithromycin, erythromycin)
• antifungal medicines (itraconazole, ketoconazole, posaconazole, voriconazole)
• HIV medicines that contain atazanavir, darunavir, efavirenz, etravirine, indinavir, nelfinavir, nevirapine, ritonavir, saquinavir, or cobicistat
• heart or blood pressure medicines (quinidine, amiodarone, diltiazem, verapamil)
• cimetidine
• mifepristone
• nefazodone
• cannabidiol
• cyclosporine
• phenytoin
• rifampin