What Is Essential
Thrombocythemia?
Understanding ET is the first step toward taking control
Essential thrombocythemia (eh-SEN-shul throm-bo-sy-THEE-mee-uh), or ET, is a rare, chronic blood cancer that causes the body to make too many plateletsSmall cell fragments that help form clots and stop bleeding.. It belongs to a group of 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.
ET starts in the bone marrow
Bone marrowThe soft, spongy tissue inside bones that makes blood cells. is the soft, spongy tissue inside bones where your stem cellsCells in the body that can develop into different types of cells. make all 3 types of 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.:
- Red blood cellsA common type of blood cell that delivers oxygen to the rest of the body. (RBC) carry oxygen throughout the body
- White blood cellsA type of blood cell that helps the body fight infections and disease. Some people with ET have high WBC counts in addition to platelets. (WBC) help fight infection and disease
- PlateletsSmall cell fragments that help form clots and stop bleeding. help the blood clot and stop bleeding
Normally, the body keeps all 3 types of blood cells in balance. But in ET, the bone marrow makes too many platelets. ET can also raise WBC counts.
What causes ET?
In people with ET, a genetic mutationAny change in the DNA sequence of a gene that can affect how cells grow or function. disrupts signals that control blood cell production, causing the bone marrow to make too many platelets.
Approximately 90% of people with ET have a mutationA change in the DNA sequence of a cell. Mutations may be inherited or something you develop during your lifetime. in the JAK2A gene that helps make a protein that controls cell growth, especially blood cells., CALRA gene involved in blood cell growth and function., or MPLA gene that helps control platelet production. genes. JAK2 is the most common of these mutations and is found in about 3 out of 5 cases. If you have ET, but don’t have a JAK2, CALR, or MPL mutation, it’s called triple-negative ETA type of ET in which 3 common gene mutations linked to the disease—JAK2, CALR, and MPL—are not found..
ET symptoms can take a toll on daily life
ET symptoms—such as fatigue, brain fog, and itching—can be disruptive and interfere with daily life. Many people with ET also worry about their health and what the future may hold.
Some people with ET have no noticeable symptoms. For others, symptoms may change over time, be easy to dismiss, or difficult to explain. That’s why it’s important to tell your doctor about anything you’re experiencing—even if you’re not sure it’s related to ET—so they can better understand how ET may be affecting your daily life and well-being.
ET can affect you in ways others—even doctors—may not see or fully understand. This can feel isolating, but it’s important to know you’re not alone.
In a survey, people with ET report:
problems
The risks of ET go beyond high platelet counts
Even when blood counts and symptoms seem under control, the cells driving ET can remain active in the bone marrow. This means the risks of blood clotsWhen blood platelets, proteins, and cells stick together, forming a mass that can slow or block blood flow., bleeding, or disease progressionWhen a disease spreads, becomes more advanced, or changes into a more serious form over time. may still be present. That’s why it’s important to understand the risks and work with your doctor on a treatment plan that goes beyond platelet control.
What are the health risks associated with ET?
Blood clots
In ET, excess, abnormal platelets can stick together and slow down blood flow, causing blood clots. These clots can lead to serious complications, including:
- Stroke
- Heart attack
- Deep vein thrombosisA blood clot that forms in a deep vein, most often in the leg, and can block blood flow back to the heart. (DVT)
- Pulmonary embolismA sudden blockage in an artery in the lungs, usually caused by a blood clot that breaks loose and travels from another part of the body.
of blood clots
Bleeding and bruising
Extremely high platelet levels can sometimes interfere with normal clotting. This can lead to bruising, nosebleeds, heavy menstrual periods, or bleeding that is difficult to stop.
Can ET progress to something more serious?
For some people, ET can progress to a more aggressive type of blood cancer over time, including myelofibrosisA rare type of cancer that starts in the bone marrow, leading to scarring and making it harder to produce blood cells. (MF) or acute myeloid leukemiaA rare, fast-growing cancer of the blood and bone marrow that can spread to other parts of the body. (AML).
The risk of disease progression increases the longer you have ET
ET treatment may evolve with your needs
The goals of ET treatment include lowering the risk of clots and disease progression, controlling blood counts, and managing symptoms that affect your daily life.
When HU may no longer be the right fit
HydroxyureaA type of chemotherapy that reduces the production of abnormal blood cells and lowers the risk of blood clots. (HU) is a chemotherapyA treatment that uses drugs to kill cancer cells or slow their growth. that is commonly the first treatment used for ET. For some people, it may not work well enough or may cause side effects that make it difficult to continue.
HU intolerance means side effects make it difficult or unsafe to continue treatment, including:
- HU-related fever
- Leg ulcers
- Other significant skin or mouth irritations
HU resistance means HU is not controlling ET well enough at a dose your doctor considers appropriate. Signs of HU resistance may include:
- Platelet or WBC counts that remain above treatment goals
- Platelet counts that remain elevated despite a high dose of HU
- ET-related symptoms that continue despite treatment
Could it be time to move on from HU?
How well a treatment works—and how well you tolerate it—can change over time. Regular blood tests and honest conversations about your symptoms and any side effects you’re experiencing can help you and your doctor determine whether your current treatment is still meeting your needs.
If HU is not working well enough or you cannot tolerate it, talk to your doctor about your treatment options.
FAQs about ET
Is essential thrombocythemia a cancer or a blood disorder?
What causes essential thrombocythemia?
Is essential thrombocythemia genetic or hereditary?
What are the most common symptoms of essential thrombocythemia?
Can you have essential thrombocythemia without any symptoms?
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 increased liver function tests, low red blood cell counts (anemia), fever, increased protein in the urine, bacterial infection, itching, and weight loss.
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.
What is BESREMi used for?
BESREMi is for the treatment of adults with essential thrombocythemia.
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.