BESREMi PEN
BESREMi is a prescription medicine that is used to treat adults with polycythemia vera
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Financial Savings & Personalized Support
Financial Savings
& Personalized
Support
Support throughout your BESREMi journey
Starting a new treatment can be overwhelming—navigating insurance, administration, and questions. When you start BESREMi, you can enroll in PharmaEssentia SOURCE, which offers personalized support to help you along every step of the way.
Get BESREMi for as little as $0 per month*
You may be eligible for the copay and coinsurance assistance program if you:
- Have commercial (private) insurance that covers BESREMi
- Live in the United States or a US territory
- Have a prescription for BESREMi from your doctor
BESREMi has broad national coverage across all insurance providers inclusive of Medicare, Medicaid, and commercial insurance.
Our PharmaEssentia SOURCE Case Managers are here for you
Once you are enrolled in PharmaEssentia SOURCE, one of our Case Managers will assist you with starting and staying on BESREMi. Case Managers can:
- Help you find resources for financial support
- Explain what you might expect during treatment with BESREMi
- Teach you how to properly use BESREMi Pen™
- Answer any questions you may have about BESREMi
Speak with a PharmaEssentia SOURCE Case Manager by calling 800-700-5053 between 8:00 AM and 8:00 PM ET, Monday through Friday.
A Welcome Kit for your BESREMi treatment
Taking your medicine as prescribed by your doctor is an important part of treating your disease. If you have been prescribed BESREMi Pen, you'll receive a Welcome Kit that includes:
- Instructions for Use: Describes how to prepare, inject, and dispose of BESREMi Pen
- Pen Placemat: Outlines what you’ll need to self-administer BESREMi Pen (includes a QR code to watch an instructional video)
- Your Guide to BESREMi: Provides information about PV and BESREMi
- What to Expect Guide: Shares tips for starting treatment with BESREMi
- PharmaEssentia SOURCE Brochure: Offers resources for one-on-one training and financial support
- Treatment Tracker Notepad: Helps you create reminders and record details about each injection
- BESREMi Prescribing Information 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.
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:
Do not take BESREMi if you:
- 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 for BESREMi.
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.MORE 
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.
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.MORE
What is the most important information I should know about BESREMi®?
BESREMi® may cause you to develop
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.MORE
What is the most important information I should know about BESREMi®?
BESREMi can cause serious side effects that may cause death or may worsen certain serious
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BESREMi, the BESREMi logo, and PharmaEssentia are registered trademarks of PharmaEssentia Corporation, and BESREMi Pen, the BESREMi Pen logo, the PharmaEssentia logo, PharmaEssentia SOURCE, and the PharmaEssentia SOURCE logo are trademarks of PharmaEssentia Corporation.
US-BSRM-2400203 (v2.0) 06/2025