PV is a long-term illness that makes your blood thicker than normal. In PV, a person’s body produces an abnormal number of blood cells. This may include red blood cells, white blood cells, and platelets. This could raise your risk of developing serious problems like blood clots, a heart attack, or a stroke. But with regular checkups and the right care, you can help lower your risk.

PV is a progressive disease, meaning that it may change over time. You may not always notice the impact of PV right away because changes can happen gradually. That’s why it’s important to take an active role in managing your own care by routinely monitoring your PV. Tracking your blood counts, procedures such as phlebotomy, and changes in daily activities can help you share a more complete picture with your doctor.

PV is a chronic disease that may get worse over time, but it can be managed with treatment. Some treatments may help control blood counts and reduce symptoms. In rare cases, PV can turn into other blood diseases like myelofibrosis or leukemia. That’s why staying proactive by paying attention to how PV may be affecting your energy, activities, and daily life can help you identify important changes to discuss with your doctor.

Your spleen is usually about the size of your fist. But in people with PV, it can get bigger.
In PV, the bone marrow makes too many red blood cells, white blood cells, and platelets. As a result of the increased number of blood cells, your spleen works harder than normal. This may cause the spleen to get bigger. This condition is called an enlarged spleen, or splenomegaly.

For some people with PV, a bigger spleen can be a sign that the disease is getting worse. That’s why it’s important to have your spleen checked regularly as part of your PV care.  

Recognizing the signs and symptoms of an enlarged spleen can help you share your concerns with your doctor so you can take an active role in managing your PV.

Since your spleen is located in your abdominal area, a swollen or enlarged spleen can cause various symptoms, including:

• Discomfort in your stomach
• Pain under your left ribs
• Feeling full too soon when eating—even if you’ve only had a small amount of food

It’s important to work with your doctor to find out your spleen size early—usually when you’re first diagnosed with PV. This is called your ’baseline’ spleen size.

Your doctor may check your spleen during a physical exam by gently pressing on the upper left side of your belly to feel if it’s larger than normal.

Sometimes, it can be hard to accurately measure spleen size through a physical exam alone. Your doctor may order a scan or imaging test to get a clearer picture. These tests may include:

Ultrasound

Computed tomography,
  also called a CT scan

Magnetic resonance
imaging (MRI)

Early identification of an enlarged spleen is important and may help your doctor see if your PV is progressing or to see how well your treatment is working. Remember, it’s important to regularly keep track of any changes in your spleen size or symptoms.

You won’t be able to pick up JAKAFI or JAKAFI XR at a local pharmacy. JAKAFI or JAKAFI XR will be sent to you from a specialty pharmacy. 

To help you avoid possible interactions between drugs, it’s important that you tell your local pharmacist that you’re taking JAKAFI or JAKAFI XR. It’s also important to tell the specialty pharmacy about any other medicines, vitamins, and supplements you’re taking.

For more information about getting your JAKAFI or JAKAFI XR prescription filled, contact IncyteCARES for JAKAFI at 1-855-452-5234, Monday through Friday, 8 AM–8 PM ET, or visit IncyteCARES.com/JAKAFI.

JAKAFI or JAKAFI XR may lower your red blood cell, white blood cell, and platelet counts. Your doctor will do blood tests to monitor your blood counts regularly while you’re taking JAKAFI or JAKAFI XR. Your doctor may lower your dose of JAKAFI or JAKAFI XR, temporarily stop JAKAFI or JAKAFI XR, or give blood transfusions based on the results of your blood tests.

In a study, JAKAFI was compared with other standard therapies in people with PV who had already taken hydroxyurea and it did not work well enough or they could not tolerate it. The people who entered the study had an enlarged spleen due to PV. The main goal of the study included controlled hematocrit levels and reduction in spleen size.

Based on the results of the study, 23% of people (25 out of 110) who received JAKAFI achieved both hematocrit control and reduced spleen size by at least 35% compared with <1% of people (1 out of 112) who received other therapies. 

Looking at spleen size reduction alone, 40% of people (44 out of 110) taking JAKAFI had a reduction of at least 35% in spleen size compared with <1% of people (1 out of 112) on other therapies.

In people who achieved both hematocrit control and reduced spleen size with JAKAFI at 8 months, 76% (19 out of 25) maintained their response at approximately 20 months.

JAKAFI or JAKAFI XR can cause serious side effects, including:  

Low blood counts: JAKAFI or JAKAFI XR may cause low platelet, red blood cell, and white blood cell counts. If you develop bleeding, stop taking JAKAFI or JAKAFI XR and call your doctor. Your doctor will do a blood test to check your blood counts before you start and regularly during your treatment. Your doctor may change your dose or stop your treatment based on the results of your blood tests.
Tell your doctor right away if you develop or have worsening symptoms such as

• unusual bleeding
• bruising
• tiredness
• shortness of breath
• a fever

Infection: You may be at risk for developing a serious infection during treatment with JAKAFI or JAKAFI XR. Tell your doctor if you develop any of the following symptoms of infection:

• chills
• nausea
• vomiting
• aches
• weakness
• fever
• painful skin rash or blisters

Worsening of symptoms after interrupting or stopping treatment. Signs and symptoms of myelofibrosis may worsen after you stop treatment.
Do not interrupt or stop treatment without talking to your doctor. Tell your doctor right away if you have any of the following after stopping treatment:

• fever
• trouble breathing
• weakness
• night sweats
• feeling dizzy or lightheaded
• pain in left upper stomach area or left shoulder

Cancer: Some people have had certain types of non-melanoma skin cancers during treatment with JAKAFI or JAKAFI XR. Your doctor will regularly check your skin during your treatment. Tell your doctor if you develop any new or changing skin lesions during treatment.

Increases in cholesterol: You may have changes in your blood cholesterol levels during treatment with JAKAFI or JAKAFI XR. Your doctor will do blood tests to check your cholesterol levels about every 8 to 12 weeks after you start taking JAKAFI or JAKAFI XR and as needed.

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 while using another JAK inhibitor to treat rheumatoid arthritis:   
Get emergency help right away if you get any symptoms of a heart attack or stroke during treatment with JAKAFI or JAKAFI XR, 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 people taking another JAK inhibitor for rheumatoid arthritis and may be life-threatening.
Tell your doctor right away if you have any signs and symptoms of blood clots during treatment with JAKAFI or JAKAFI XR, including:

• swelling, pain, or tenderness in one or both legs
• sudden, unexplained chest or upper back 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. People who smoke or who smoked in the past have an added risk of new cancers.

The most common side effects of JAKAFI or JAKAFI XR in adults with PV include:

• low platelet counts
• low red blood cell counts
• bruising
• dizziness
• headache
• diarrhea

These are not all the possible side effects of JAKAFI or JAKAFI XR. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088. You may also report side effects to Incyte Corporation at 1-855-463-3463.

Before taking JAKAFI or JAKAFI XR, tell your doctor about all of your medical conditions, including if you:

• have or have had low white or red blood cell counts
• have an infection
• have or had tuberculosis (TB), or have been in close contact with someone who has TB
• have had shingles (herpes zoster)
• have or had hepatitis B
• have a high level of fat in your blood (high blood cholesterol or triglycerides)
• have had a blood clot, heart attack, other heart problems, or stroke
• are a current or past smoker
• have had cancer in the past
• have or have had kidney problems or are on dialysis. If you are on dialysis, JAKAFI or JAKAFI XR should be taken after your dialysis.
• have or have had liver problems
• are pregnant or plan to become pregnant. It is not known if JAKAFI or JAKAFI XR will harm your unborn baby.
• are breastfeeding or plan to breastfeed. It is not known if JAKAFI or JAKAFI XR passes into your breast milk. Do not breastfeed during treatment with JAKAFI or JAKAFI XR and for 2 weeks after the final dose.

Women should not take JAKAFI or JAKAFI XR while pregnant or planning to become pregnant. Do not breastfeed during treatment with JAKAFI or JAKAFI XR and for 2 weeks after the final dose.

Tell your doctor about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements. Taking JAKAFI or JAKAFI XR with certain other medicines may affect how JAKAFI or JAKAFI XR works. Know the medicines you take. Keep a list of them to show your doctor and pharmacist when you get a new medicine.

Everyone responds to JAKAFI or JAKAFI XR differently, so it may take time to see results. Your doctor will regularly do blood tests to monitor your blood counts and check your spleen size during your treatment with JAKAFI or JAKAFI XR. Based on how your body responds to treatment, your doctor may adjust your dose of JAKAFI or JAKAFI XR. It is important to tell your doctor about how you’re feeling and how your PV is affecting you.

Living with PV is frustrating enough. You shouldn’t have to settle for a treatment that isn’t working well enough for you. If your blood counts are elevated or uncontrolled on hydroxyurea, you need frequent phlebotomies, or you notice the overall impact of PV on your daily routine, it might be time to talk with your doctor about changing to treatment that may help you feel more like yourself.

Tell your doctor about any concerns you have and ask if JAKAFI or JAKAFI XR may be a treatment option for you.

JAKAFI XR has the same active ingredient as JAKAFI. JAKAFI XR is an extended-release tablet taken once a day, at the same time each day.  

JAKAFI is an immediate-release tablet that is taken twice a day by mouth. Because everyone is different, and because your dosage may change during treatment, JAKAFI and JAKAFI XR are available in different dosage strengths. You should take the dosage prescribed to you by your doctor.

PV is a chronic disease that may get worse over time. It doesn’t go away, but it can be managed with the right treatment. That’s why it’s important to stay on treatment to help keep the disease under control and to slow down its progression.

If your doctor decides that JAKAFI or JAKAFI XR is right for you, it's important that you continue to take JAKAFI or JAKAFI XR as prescribed. JAKAFI and JAKAFI XR are long-term treatments.

It is important to take JAKAFI and JAKAFI XR exactly as directed by your doctor. Do not change your dose or stop taking JAKAFI or JAKAFI XR without first talking with your doctor. However, if you develop bleeding, stop taking JAKAFI or JAKAFI XR and call your doctor right away.

Store JAKAFI and JAKAFI XR at room temperature 68 °F to 77 °F (20 °C to 25 °C). 

Keep JAKAFI and JAKAFI XR and all medicines out of the reach of children.

JAKAFI or JAKAFI XR can be taken with or without food.

If you miss a dose of JAKAFI or JAKAFI XR, take your next dose at your regular time. Do not take 2 doses at the same time.

If you take too much JAKAFI or JAKAFI XR, call your doctor or go to the nearest hospital emergency room right away.  

Take the bottle of JAKAFI or JAKAFI XR with you.

Getting a new prescription or insurance plan can be confusing, especially when you’re trying to figure out what’s covered. Ask your doctor about enrolling you in IncyteCARES and see how IncyteCARES can help eligible people with insurance assistance. Our team is available to walk you through this process.

IncyteCARES is a support program that helps eligible patients get started with JAKAFI or JAKAFI XR and stay on track during treatment. It offers helpful information, insurance and access support, and ongoing guidance.

Talk to your doctor about IncyteCARES to see how it might support you.

If you’re eligible, the IncyteCARES Savings Program may help lower your out-of-pocket costs. There’s also a Patient Assistance Program (PAP) that may provide JAKAFI or JAKAFI XR at no cost for people who qualify.

Talk to your doctor or visit IncyteCARES.com to learn more.