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Explore PLEGRIDY efficacy

In a clinical study, PLEGRIDY was shown to work in 3 key areas

Based on a 1-year study against placebo, people taking PLEGRIDY had fewer relapses, delayed disability progression, and had fewer brain lesions on magnetic resonance imaging (MRI).*

Helps reduce relapses

In a 1-year study, 512 people with relapsing MS taking PLEGRIDY had fewer relapses compared with 500 people in the placebo group. People taking PLEGRIDY experienced 0.26 relapses per year compared with 0.40 in the placebo group.

Helps slow physical disability progression

In the same 1-year study, people with relapsing MS taking PLEGRIDY had a 38% lower risk of disability progression as compared to placebo. 7% of people taking PLEGRIDY experienced disability progression compared with 11% of those taking placebo.

Helps reduce brain lesions on MRI*

3.6 T2 lesions with PLEGRIDY
vs
10.9 T2 lesions with placebo

T2 LESIONS: Lesions that show the long-term impact of inflammation on your brain.

0.2 Gd+ lesions with PLEGRIDY
vs
1.4 Gd+ lesions with placebo

GADOLINIUM-ENHANCED (Gd+) LESIONS: A dye containing gadolinium is used to show lesions that indicate active inflammation.

One way to monitor relapsing multiple sclerosis (MS) is by observing lesions, or areas of damage, in your brain. It’s important to monitor lesions because they can occur with or without any visible symptoms. 

PLEGRIDY reduced the number of new or newly enlarging T2 lesions and Gd+ lesions compared with people taking placebo.†

*The link between brain lesions and the progression of relapsing MS has not been confirmed.
†Data measured at 48 weeks among 457 people with relapsing MS taking PLEGRIDY and 476 people in the placebo group.

Watch a PLEGRIDY patient video

Hear personal stories from real patients taking PLEGRIDY.

Watch video

More to explore with PLEGRIDY

Questions for your healthcare provider

Download a list of questions to help start a conversation with your healthcare provider about your relapsing MS treatment. 
Download guide
PLEGRIDY Start Form

If you’re considering PLEGRIDY, get a head start on the process by taking this form to your next visit. It includes step-by-step instructions for you and your healthcare provider.
Download Start Form

Watch a PLEGRIDY patient video

Hear personal stories from real patients taking PLEGRIDY.

Watch video
Next: Safety and side effects

What is PLEGRIDY® (peginterferon beta-1a)?

PLEGRIDY is a prescription medicine used to treat relapsing forms of multiple sclerosis (MS), to include clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease in adults.

It is not known if PLEGRIDY is safe and effective in people under 18 or over 65 years of age.

Important Safety Information

Who should not take PLEGRIDY?

  • Do not take PLEGRIDY if you are allergic to interferon beta or peginterferon, or any of the other ingredients in PLEGRIDY

What is the most important information I should know about PLEGRIDY?

PLEGRIDY can cause serious side effects, including:

  • Liver problems, or worsening of liver problems, including liver failure and death. Symptoms may include yellowing of your skin or the white part of your eye, nausea, loss of appetite, tiredness, bleeding more easily than normal, confusion, sleepiness, dark colored urine, and pale stools. During your treatment with PLEGRIDY you will need to see your healthcare provider regularly. You will have regular blood tests to check for these possible side effects

  • Depression or suicidal thoughts. Symptoms may include new or worsening depression (feeling hopeless or bad about yourself), thoughts of hurting yourself or suicide, irritability (getting upset easily), nervousness, or new or worsening anxiety

Call your healthcare provider right away if you have any of the symptoms listed above.

Before taking PLEGRIDY, tell your healthcare provider about all of your medical conditions, including if you:

  • Are being treated for a mental illness or had treatment in the past for any mental illness, including depression and suicidal behavior

  • Have or had liver problems, low blood cell counts, bleeding problems, heart problems, seizures (epilepsy), thyroid problems, or any kind of autoimmune disease (where the body’s immune system attacks the body’s own cells)

  • Have or had an allergic reaction to rubber or latex. The tip of the cap of the PLEGRIDY prefilled syringe for intramuscular use is made of natural rubber latex

  • Are pregnant or plan to become pregnant. It is not known if PLEGRIDY can harm your unborn baby

  • Are breastfeeding or plan to breastfeed. PLEGRIDY may pass into your breastmilk. Talk to your healthcare provider about the best way to feed your baby if you take PLEGRIDY

Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins, and herbal supplements.

What are the possible side effects of PLEGRIDY?

PLEGRIDY may cause serious side effects, including:

  • serious allergic reactions. Serious allergic reactions can happen if you take PLEGRIDY. Symptoms may include itching, swelling of the face, eyes, lips, tongue, or throat, trouble breathing, feeling faint, anxiousness, skin rash, hives, or skin bumps. Get emergency help right away if you have any of these symptoms. Talk to your healthcare provider before taking another dose of PLEGRIDY

  • injection site reactions. PLEGRIDY may commonly cause redness, pain, itching or swelling at the place where the injection was given. Call your healthcare provider right away if an injection site becomes swollen and painful or the area looks infected. You may have a skin infection or an area of severe skin damage (necrosis) requiring treatment by a healthcare provider

  • heart problems, including congestive heart failure. Call your healthcare provider right away if you have worsening symptoms of heart failure such as shortness of breath or swelling of your lower legs or feet while using PLEGRIDY

    • Some people using PLEGRIDY may have other heart problems, including low blood pressure, fast or abnormal heartbeat, chest pain, heart attack, or a heart muscle problem (cardiomyopathy)

  • blood problems and changes in your blood tests. PLEGRIDY can decrease your white blood cells or platelets, which can cause an increased risk of infection, bleeding, or anemia and can cause changes in your liver function tests. Your healthcare provider will do tests to monitor for side effects while you use PLEGRIDY

  • thrombotic microangiopathy (TMA). TMA is a condition that involves injury to the smallest blood vessels in your body. TMA can also cause injury to your red blood cells (the cells that carry oxygen to your organs and tissues) and your platelets (cells that help your blood clot) and can sometimes lead to death. Your healthcare provider may tell you to stop taking PLEGRIDY if you develop TMA

  • pulmonary arterial hypertension. Pulmonary arterial hypertension can occur with interferon beta products, including PLEGRIDY. Symptoms may include new or increasing fatigue or shortness of breath. Contact your healthcare provider right away if you develop these symptoms

  • autoimmune diseases. Problems with easy bleeding or bruising (idiopathic thrombocytopenia), thyroid gland problems (hyperthyroidism and hypothyroidism), and autoimmune hepatitis have happened in some people who use interferon beta

  • seizures. Some people have had seizures while taking PLEGRIDY, including people who have never had seizures before

The most common side effects of PLEGRIDY include:

  • flu-like symptoms. Many people who take PLEGRIDY have flu-like symptoms especially early in the course of therapy. These symptoms are not really the flu. You cannot pass it on to anyone else

    • You may be able to manage these flu-like symptoms by taking over-the-counter pain and fever reducers and drinking plenty of water

Flu-like symptoms or other common side effects of PLEGRIDY may include: headache, muscle and joint aches, fever, chills, or tiredness.

These are not all of the possible side effects of PLEGRIDY.

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Please see full Prescribing Information and Medication Guide.

This information does not take the place of talking with your healthcare provider about your medical condition or your treatment.

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©2024 Biogen. All rights reserved. 04/24 PLG-US-1210 V2
This site is intended for residents 18 years or older of the United States, Puerto Rico, and US territories.

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