Get a better understandingof myelofibrosis

Myelofibrosis (MF) is part of a group of blood cancers called myeloproliferative neoplasms (MPNs). MF is a rare bone marrow cancer that causes scarring in your bone marrow (the spongy tissue inside your bones that makes blood cells) and can get worse over time. The bone marrow scarring that happens in MF affects the way your body usually makes healthy blood cells. Your blood cells have important functions:

red blood cells carry oxygen throughout your body

platelets help your blood clot

white blood cells help your body fight infection

What is the cause of myelofibrosis?

When you have myelofibrosis, there are changes, called mutations, in the DNA of your bone marrow stem cells that cause your bone marrow to make too many abnormal blood cells. These abnormal cells take over, resulting in inflammation that leads to scar tissue (fibrosis).

As the scar tissue continues to form, it doesn’t allow the bone marrow to make enough healthy blood cells, which can cause a drop in:

RED BLOOD CELLS
PLATELETS
WHITE BLOOD CELLS

Explore myelofibrosis symptoms and signs
that myelofibrosis is progressing

Signs and symptoms

What is VONJO® (pacritinib)?

VONJO is a prescription medicine used to treat adults with certain types of myelofibrosis (MF) who have a platelet count below 50,000 per microliter. This indication is approved under accelerated approval based on spleen volume reduction. Continued approval for this indication may depend on proof and description of clinical benefit in a confirmatory trial(s).

It is not known if VONJO is safe and works in children.

Important Safety Information

Do not use VONJO if you are taking other medications that are strong CYP3A4 inhibitors or inducers.

What are the serious side effects of VONJO?

Bleeding. VONJO can cause severe bleeding, which can be serious and, in some cases, may lead to death.

Stop taking VONJO and tell your healthcare provider right away if you develop any of these symptoms: unusual bleeding, bruising, and fever. Get medical help right away for any bleeding that you cannot stop
You will need to stop taking VONJO 7 days before any planned surgery or invasive procedure (such as a heart catheterization, 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 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. Urgently seek emergency medical attention if diarrhea becomes severe.

Worsening low platelet counts.

Changes in the electrical activity of your heart called QTc prolongation. QTc prolongation can cause irregular heartbeats that can be life-threatening. 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 have happened, especially in those who have cardiovascular risk factors and who are current or past smokers taking another Janus associated kinase (JAK) inhibitor to treat rheumatoid arthritis.

Get emergency help right away if you have any symptoms of a heart attack or stroke during treatment with 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; or 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 for rheumatoid arthritis and may be life-threatening.

Tell your healthcare provider right away if you have any signs and symptoms of blood clots during treatment with VONJO, including: swelling, pain, or tenderness in one or both legs; sudden, unexplained chest pain; or shortness of breath/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 have 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. People who take VONJO may 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 with VONJO.

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.

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

Especially tell your healthcare provider if you take hormonal contraceptives (birth control). Hormonal birth control methods, except for intrauterine systems containing levonorgestrel, may not work during treatment with VONJO and for 30 days after your last dose. Talk to your healthcare provider about birth control methods that may be right for you during treatment with VONJO.

Your healthcare provider may change your dose or how often you take VONJO, temporarily stop, or permanently stop treatment with VONJO if you have certain side effects.

What should I tell my healthcare provider before starting VONJO?

Have active bleeding, have had severe bleeding, or plan to have surgery or noninvasive procedures. You should stop taking VONJO 7 days before any planned surgery or invasive procedures
Have diarrhea or commonly have loose stools
Have had a blood clot, heart attack, other heart problems, or stroke
Have a history of low blood levels of potassium. It is important that you get blood tests done during treatment with VONJO to monitor your body salts (electrolytes)
Smoke or were a smoker in the past
Have had any other cancers
Have an infection
Have nausea or vomiting
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 of VONJO. Talk to your healthcare provider about the best way to feed your baby during this time

What are the most common side effects with VONJO?
Low platelet count (thrombocytopenia), nausea, vomiting, low red blood cell count (anemia), and swelling of your ankles, legs, and feet.

Your healthcare provider will do blood tests and an electrocardiogram (ECG) before you start treatment with VONJO and as needed during treatment to check for side effects.

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 with VONJO.

If you suspect that you have experienced a side effect, call your healthcare provider. You may also report side effects to the US Food and Drug Administration (FDA) at 1-800-FDA-1088.

Please see the full Prescribing Information for VONJO.