PLEGRIDY™ (peginterferon beta-1a) is an interferon for people with relapsing forms of MS. PLEGRIDY can help reduce relapses, delay the progression of physical disability, and reduce brain lesions on MRI. Plegridy is specifically indicated for relapsing forms of multiple sclerosis.

Plegridy (peginterferon beta-1a) is a subcutaneous injectable therapy, in which interferon beta-1a is pegylated to extend its half-life to permit a less frequent dosing schedule. Interferon-beta (IFN-beta) is a polypeptide, normally produced by fibroblasts, that has antiviral and antiproliferative effects. Binding of IFN-beta to its receptor induces a complex transcriptional response. In immune cells (the most likely target of IFN-beta’s therapeutic effect in MS), IFN-beta reduces antigen presentation and T-cell proliferation, alters cytokine and matrix metalloproteinase (MMP) expression, and restores suppressor function. Therapeutic forms of IFN-beta can be produced in bacterial expression systems (IFN-beta1b) or in mammalian cells (IFN-beta1a). The exact mechanism by which Plegridy  exerts its effects in patients with multiple sclerosis is unknown.


Plegridy is supplied as a solution for subcutaneous administration. The recommended dosage of Plegridy is 125 micrograms injected subcutaneously every 14 days. Patients should start treatment with 63 micrograms on day 1. On day 15 (14 days later), the dose is increased to 94 micrograms, reaching the full dose of 125 micrograms on day 29 (after another 14 days). Patients should continue with the full dose (125 micrograms) every 14 days thereafter.

Efficacy Results:

The efficacy data from the first year of the ATTAIN study represent patients who have three years of continuous, fixed-dose treatment with PLEGRIDY. The efficacy findings are consistent with the Phase 3 ADVANCE study and continue to support PLEGRIDY’s robust efficacy over time:

  • Patients with RRMS who were administered PLEGRIDY subcutaneously every two weeks over the three year period maintained positive efficacy results on clinical outcomes including annualized relapse rate (ARR), the proportion of patients suffering a relapse, and the proportion of patients with 24-week confirmed disability progression.
  • PLEGRIDY also showed continued efficacy over the three year period across important MRI measures: number of gadolinium (Gd+) enhanced lesions, new T1-hypointense lesions, and new or newly enlarging T2-hyperintense lesions.

Additionally, the results from the study included a post-hoc analysis on NEDA outcomes, which in ATTAIN were defined as no evidence of disease activity on clinical and MRI measures, indicating no relapses and no onset of 24-week disability progression, no Gd+ lesions, and no new or enlarging T2-hyperintense lesions.

  • The percentage of patients in the intent-to-treat (ITT) population who achieved NEDA were 34.8 percent in year one and 54.3 percent in year two of the ADVANCE study, and 48.7 percent in year one of the ATTAIN study, demonstrating continued efficacy over a period of three years.

“The ATTAIN data presented at AAN reinforce the known benefits PLEGRIDY provides people with MS – long-term efficacy paired with a well-defined safety profile,” said Gilmore O’Neill, vice president, Multiple Sclerosis Research and Development, Biogen. “As we continue to introduce PLEGRIDY in markets around the world, we are proud to bring innovation to the interferon class in an effort to advance patient options and care.”

Side Effects:

PLEGRIDY can cause serious side effects. Call your healthcare provider right away if you have any of the symptoms listed below.

  • 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

Do not take PLEGRIDY if you are allergic to interferon beta or peginterferon beta-1a, or any of the other ingredients in PLEGRIDY.

Before taking PLEGRIDY, tell your healthcare provider 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
  • Take prescription and over-the-counter medicines, vitamins, and herbal supplements
  • Are pregnant or plan to become pregnant. It is not known if PLEGRIDY will harm your unborn baby. Tell your healthcare provider if you become pregnant during your treatment with PLEGRIDY
  • Are breastfeeding or plan to breastfeed. It is not known if PLEGRIDY passes into your breast milk. Talk to your healthcare provider about the best way to feed your baby if you use PLEGRIDY

PLEGRIDY can cause additional serious side effects including:

  • Serious allergic reactions. Serious allergic reactions can happen quickly. Symptoms may include itching, swelling of the face, eyes, lips, tongue, or throat, trouble breathing, feeling faint, anxiousness, skin rash, hives, or skin bumps
  • Injection site reactions. PLEGRIDY may commonly cause redness, pain 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 and it does not heal within a few days. 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. While PLEGRIDY is not known to have any direct effects on the heart, some people who did not have a history of heart problems developed heart muscle problems or congestive heart failure after taking interferon beta. If you already have heart failure, PLEGRIDY may cause your heart failure to get worse. 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 heart beat, chest pain, heart attack, or a heart muscle problem (cardiomyopathy)
  • 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
  • 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 should do blood tests while you use PLEGRIDY to check for side effects
  • 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 early in the course of therapy. These symptoms are not really the flu. You cannot pass it on to anyone else. Symptoms may include headache, muscle and joint aches, fever, chills or tiredness
    • You may be able to manage these flu-like symptoms by taking over-the-counter pain and fever reducers and drinking plenty of water. For many people, these symptoms lessen or go away over time

Biogen LogoBiogen is one of the world’s leading biotechnology companies, with a focus on developing therapies for neurodegenerative, hematologic and autoimmune disorders. Founded in 1978, our work in biologics and small-molecule drug discovery has led to the world’s most extensive portfolio of multiple sclerosis therapies and innovative new treatments for hemophilia patients. Our experience, capabilities and passion for innovation have enabled us to build a pipeline and develop advanced research programs that include exploration of potential candidates for serious and difficult-to-treat neurodegenerative diseases and fibrotic and nonmalignant blood disorders.

We are committed to research that uncovers the underlying biology of complex diseases. Our focus is on illnesses with few, if any, treatment options. Biogen’s success will always be measured by the answer to a simple question: Have we truly made a difference in the lives of patients?

Plegridy Patient Information: