Frequently
Asked
Questions
About ET
and BESREMi

Essential thrombocythemia, or ET, is a rare, chronic blood cancer that causes the bone marrow to make more platelets than your body needs. It belongs to a group of cancers called myeloproliferative neoplasms, or MPNs. ET is sometimes referred to as primary thrombocythemia or essential thrombocytosis.

Essential thrombocythemia is a rare, chronic blood cancer. It belongs to a group of blood cancers called myeloproliferative neoplasms, or MPNs.

Essential thrombocythemia (ET) usually develops when a mutation in a stem cell disrupts the signals that control blood cell production. This causes the bone marrow to make too many platelets.

Most people with ET have a mutation in the JAK2, CALR, or MPL genes. The reason these mutations develop is usually unknown.

Essential thrombocythemia is usually caused by an acquired genetic mutation. "Acquired" means the mutation develops during a person's lifetime rather than being inherited from a parent.

The most common mutations affect the JAK2, CALR, or MPL genes. The reasons these mutations develop is usually unknown.

Essential thrombocythemia (ET) is rare. About 24 out of every 100,000 people in the United States are currently living with ET.

Some people with essential thrombocythemia (ET) have no symptoms. For those who do experience signs and symptoms of ET, they can be vague, come and go, develop gradually, or have a significant impact on daily life.

Be sure to tell your doctor if you experience any of these common ET symptoms:

Head

• Headaches
• Dizziness or light headedness
• Difficulty concentrating or "brain fog"
• Blurry vision or other vision changes

Hands and feet

• Burning, redness, or pain in hands or feet
• Coldness or bluish color of fingers or toes

General

• Fatigue
• Sleep problems
• Nosebleeds, bruising easily, heavier or longer menstrual periods
• Blood in your stool or urine
• Nausea
• Abdominal pain or discomfort
• Feeling full sooner than usual after meals
• Shortness of breath, chest pain, or cough
• Itching
• Sexual problems
• Slurred speech

Yes. Some people with essential thrombocythemia (ET) have no noticeable symptoms and are only diagnosed after a routine blood test shows a high platelet count.

Even if you feel well, regular monitoring remains important because ET still carries risks of blood clots and progression to a more serious type of blood cancer.

For people with essential thrombocythemia (ET), fatigue can be more than feeling tired after a long day. It may feel overwhelming, hard to shake, or out of proportion to your activity level. It can have a real impact on work, relationships, daily activities, and quality of life.

There often isn’t one clear cause of ET related fatigue. The disease itself, disrupted sleep, emotional distress such as stress or anxiety, other health conditions, and treatment side effects may all play a role.

Tell your doctor how much fatigue is affecting your life. They can look for possible causes and ways to help manage it.

For some people, essential thrombocythemia (ET) can progress to a more serious blood cancer, including myelofibrosis or acute myeloid leukemia.

Not everyone will experience disease progression, but the likelihood of progression increases the longer a person lives with ET. Regular blood tests and symptom monitoring can help your doctor identify changes that may be signs of disease progression.

Hydroxyurea resistance means HU is not controlling essential thrombocythemia well enough after an adequate trial of treatment. Hydroxyurea intolerance means side effects make HU difficult or unsafe to continue.

Regular monitoring and speaking up about how you're feeling can help you and your doctor determine whether HU is still meeting your needs or if it may be time to consider another option like BESREMi.

Ask your hematologist, oncologist, primary care doctor, or health plan for a referral to a doctor who regularly treats essential thrombocythemia (ET) or myeloproliferative neoplasms (MPNs).

MPN advocacy organizations and major cancer centers may also offer specialist directories. An MPN specialist can provide a consultation or work with another member of your team on your ongoing care.

BESREMi is the only FDA-approved treatment for essential thrombocythemia (ET) that targets the source of the disease in the bone marrow.

No, BESREMi is not chemotherapy. It's a type of immunotherapy called an interferon that you take once every 2 weeks. BESREMi works with your body's immune system to treat essential thrombocythemia in the bone marrow, where the disease starts.

BESREMi works with your immune system to target essential thrombocythemia where it starts—in the bone marrow. It helps regulate the production of platelets and other blood cells.

BESREMi is injected under the skin using BESREMi Pen™, a single-dose, ready-to-use pen. You administer it once every 2 weeks as prescribed by your doctor.

Your doctor will determine your prescribed dose and may increase it step by step over the first month of treatment.

Regular blood tests help your doctor monitor how well you're responding to treatment and determine whether your dose needs to be adjusted. Do not change your dose or stop treatment unless you doctor tells you to.

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
• Weight loss

If side effects come up, it’s important to talk to your doctor. They may have recommendations for ways to help manage them at home.

Store the BESREMi carton containing the pen in a refrigerator at 36 °F to 46 °F (2 °C to 8 °C). Keep it in its original carton to protect it from light. Do not freeze BESREMi Pen.

When traveling, keep BESREMi Pen cold and in your carry on bag. Review the tips for traveling with BESREMi and Instructions for Use before your trip.

When you start BESREMi, you can enroll in PharmaEssentia SOURCE for personalized support every step of the way.

Case Managers can help you navigate financial assistance options, understand what to expect during treatment, and learn how to use BESREMi Pen. You may also be eligible to get BESREMi for as little as $0 per month.*

Learn more about savings and support options to help you start and stay on BESREMi.

*Terms, conditions, and eligibility criteria apply. See PharmaEssentia SOURCE for details.