
What Is
Polycythemia Vera?

What is PV?
Polycythemia vera (pol-e-sy-THEE-me-uh VEER-uh), or PV, is a rare and chronic blood cancer. It’s part of a group of blood cancers called myeloproliferative neoplasmsA group of rare blood cancers that start in the bone marrow, where the body’s blood cells are made. (my-e-lo-pro-lif-er-a-tive neo-plasms), or MPNs.
Stem cellsCells in the body that can develop into different types of cells. in the bone marrowThe soft, spongy tissue inside bones that makes blood cells. make all the blood cellsTypes of cells that support various functions in the body. Created in the bone marrow, they begin as stem cells and mature into red blood cells, white blood cells, and platelets. in your body: red blood cellsA common type of blood cell that delivers oxygen to the rest of the body., white blood cellsA type of blood cell that helps the body fight infections and disease., and plateletsSmall cell fragments that help form clots and stop bleeding.. Your body needs a certain amount of each of these. Normally, your body keeps everything in balance.
PV occurs when a single stem cell in the bone marrow develops a mutation (or DNA change) and starts to make too many blood cells. This DNA change often happens in a gene called JAK2A gene that helps make a protein that controls cell growth, especially blood cells., which helps make a protein that controls how blood cells grow and divide. Most people with PV have a JAK2 mutationA change in the JAK2 gene that can lead to blood disorders that make too many blood cells..
The excess of blood cells can cause symptoms and complications of PV. Having too many red blood cells makes the blood thicker, which slows down its flow. Too many platelets can lead to the formation of blood clots. That’s when serious health problems, like heart attack and stroke, may occur. Your doctor may refer to these as “thrombotic events”Situations where blood clots form in a blood vessel or the heart, which can block blood flow..
It all starts in the bone marrow





What is PV?
Polycythemia vera (pol-e-sy-THEE-me-uh VEER-uh), or PV, is a rare and chronic blood cancer. It’s part of a group of blood cancers called myeloproliferative neoplasmsA group of rare blood cancers that start in the bone marrow, where the body’s blood cells are made. (my-e-lo-pro-lif-er-a-tive neo-plasms), or MPNs.
Stem cellsCells in the body that can develop into different types of cells. in the bone marrowThe soft, spongy tissue inside bones that makes blood cells. make all the blood cellsTypes of cells that support various functions in the body. Created in the bone marrow, they begin as stem cells and mature into red blood cells, white blood cells, and platelets. in your body: red blood cellsA common type of blood cell that delivers oxygen to the rest of the body., white blood cellsA type of blood cell that helps the body fight infections and disease., and plateletsSmall cell fragments that help form clots and stop bleeding.. Your body needs a certain amount of each of these. Normally, your body keeps everything in balance.
It all starts in the bone marrow





PV occurs when a single stem cell in the bone marrow develops a mutation (or DNA change) and starts to make too many blood cells. This DNA change often happens in a gene called JAK2A gene that helps make a protein that controls cell growth, especially blood cells., which helps make a protein that controls how blood cells grow and divide. Most people with PV have a JAK2 mutationA change in the JAK2 gene that can lead to blood disorders that make too many blood cells..
The excess of blood cells can cause symptoms and complications of PV. Having too many red blood cells makes the blood thicker, which slows down its flow. Too many platelets can lead to the formation of blood clots. That’s when serious health problems, like heart attack and stroke, may occur. Your doctor may refer to these as “thrombotic events”Situations where blood clots form in a blood vessel or the heart, which can block blood flow..
In one study, 39% of people with PV had a history of thrombotic events, like blood clots, heart attack, and stroke.
About 95% of all PV cases are caused by a JAK2 mutation in a stem cell. This causes too many blood cells to be made.
What do you need to know about treating PV?
If you’re living with PV, keeping your red and white blood cell and platelet counts under control is very important. In addition to putting you at risk for a thrombotic event, PV can also progress to other conditions like myelofibrosisA rare type of cancer that starts in the bone marrow, leading to scarring and making it harder to produce blood cells. (mie-uh-loh-fie-brOH-suhs) and leukemiaA type of cancer that starts in the blood or bone marrow and causes the body to rapidly produce abnormal white blood cells..
For years, management of PV has focused on making sure that your hematocritThe percentage of red blood cells in your blood. (he-mat-o-crit), or HCT, level is normal and managing symptoms to improve quality of life. The HCT test measures how much of your blood is made up of red blood cells. But PV can cause an overproduction of all blood cells, not just red blood cells, so focusing only on HCT may not be telling you and your doctor the whole story.
To see the big picture of PV, your doctor can measure your complete hematologic response (CHR)When all blood cell counts have returned to normal levels, typically after treatment for a blood-related condition., which considers:
- Red blood cell count
- White blood cell count
- Platelet count
- Time since last phlebotomyA procedure of drawing blood to reduce excess blood cells and decrease blood volume. (fluh-bot-uh-mee)
Your doctor may also look at your spleen size and whether you have had any thromboembolic eventsSituations where a blood clot breaks loose and travels to another part of the body, causing a blockage.. Together with CHR, these measurements can show if you are experiencing comprehensive disease controlWhen all blood cell counts and spleen size have returned to normal and there is an absence of thromboembolic events, typically after treatment for a blood-related condition..
Talk with your doctor about why these measures are essential to tracking how well your PV treatment is working.
Taking charge of my treatment: Tyler's story
Tyler was a teenager when he started experiencing PV symptoms, and it took almost 10 years to confirm his diagnosis. Hear how BESREMi helped Tyler get his symptoms and blood counts under control so he could stay in control of his demanding career.

Read this Important Safety Information carefully. It explains the serious risks of BESREMi and how to take it safely. Talk to your healthcare provider if you have any questions.
What is the most important information I should know about BESREMi?
BESREMi can cause serious side effects, including conditions that may cause death or may worsen certain serious diseases you may already have. If symptoms get worse, or become severe and continue, your healthcare provider may tell you to stop taking BESREMi permanently. These symptoms may go away in some people after they stop taking BESREMi.
Mental health problems, including suicide
BESREMi may cause mood or behavior problems that can get worse during treatment or after your last dose, including:
- Irritability (getting upset easily)
- Restlessness and agitation
- Confusion
- Depression (feeling low, hopeless, or bad about yourself)
- Unusually grand ideas
- Acting aggressive or impulsively
- Thoughts of hurting yourself or others, or thoughts of suicide
If you develop any of these symptoms, call your healthcare provider immediately.
New or worsening autoimmune problems
BESREMi may cause your immune system to attack healthy cells, leading to conditions such as thyroid disease, increased blood sugar (hyperglycemia), or type 1 diabetes. Call your healthcare provider if you experience:
- Extreme tiredness
- Frequent urination
- Excessive thirst
Heart problems
BESREMi may cause heart problems, including:
- Cardiomyopathy (heart muscle disease)
- Heart attack
- Irregular heartbeat (atrial fibrillation)
- Decreased blood flow to the heart
You should not take BESREMi if you have:
- Uncontrolled high blood pressure
- Congestive heart failure
- A serious abnormal heart rhythm
- Narrowing of the arteries to your heart
- Certain types of chest pain (angina)
- A recent stroke or heart attack
Who should not take BESREMi?
Do not take BESREMi if you:
- Have or had severe mental health problems, especially depression, suicidal thoughts, or attempted suicide
- Have or had a serious or untreated autoimmune disease
- Are allergic to interferon or any ingredient in BESREMi (symptoms may include itching, swelling, trouble breathing, dizziness, or chest pain)
- Have certain types of liver disease
- Have had a transplant and take immune-suppressing medication
Before using BESREMi, tell your healthcare provider about all of your medical conditions, including if you have any of the following:
- A mental illness
- Type 1 diabetes
- Heart or bleeding problems
- Problems with your immune system
- Hepatitis B or HIV infection
- Kidney or liver problems
- Are pregnant or planning to become pregnant
- BESREMi may harm your unborn baby. Use effective birth control during treatment and for at least 8 weeks after your last dose
- BESREMi may affect your menstrual cycle and could stop your periods
- Do not breastfeed while taking BESREMi
What are the possible side effects of BESREMi?
Serious side effects include:
- Low blood cell counts: taking BESREMi can lead to infections, anemia, or bleeding problems. Call your healthcare provider right away if you develop weakness and tiredness, bruising easily, nose bleeds often, fever, chills, burning and painful urination, urinating often, or coughing up yellow or pink mucus (phlegm)
- Serious allergic reactions: Get medical help right away if you get any of the following symptoms: skin rash or hives; itching; swelling of the face, eyes, lips, tongue, or throat; trouble breathing; chest pain; or feeling faint
- Eye problems: BESREMi can cause severe eye problems with your retinas that can lead to vision loss or blindness. You should have an eye exam before and during treatment with BESREMi if you have diabetes or high blood pressure and also have retinal problems
- Liver problems: BESREMi can cause increases in liver enzymes and liver damage. Your healthcare provider should do blood tests to monitor your liver enzymes and liver function before you start and during treatment with BESREMi
- Kidney problems: Your healthcare provider will do blood tests to check your kidney function before starting and during treatment with BESREMi. Tell your healthcare provider right away if you develop any symptoms of a kidney problem, including: changes in the amount or color of your urine, swelling in your ankles, blood in your urine, or loss of appetite
- Tooth and gum problems: BESREMi can cause tooth loss and/or dry mouth. It is important for you to brush your teeth well, two times each day and have regular dental examinations during treatment with BESREMi
- Skin reactions: BESREMi may cause reaction such as rash, itching, and hair loss
- Increased triglycerides: You may require blood tests to monitor levels
The most common side effects of BESREMi include:
- Flu-like symptoms, including tiredness, weakness, fever, chills, muscle aches, and joint pain
- Itching
- Sore throat
These are not all of the possible side effects of BESREMi.
Call your doctor for medical advice about side effects. You may report side effects to PharmaEssentia at 1-800-999-2449 or FDA at 1-800-FDA-1088.
Please see full Prescribing Information, including Boxed Warning and Medication Guide.
Read this Important Safety Information carefully. It explains the serious risks of BESREMi and how to take it safely.
Talk to your healthcare provider if you have any questions.
What is the most important information I should know about BESREMi?
BESREMi can cause serious side effects, including conditions that may cause death or may worsen certain serious diseases you may already have. If symptoms get worse, or become severe and continue, your healthcare provider may tell you to stop taking BESREMi permanently. These symptoms may go away in some people after they stop taking BESREMi.



