800.456.2255

Indication and Important Safety Information

Indication

PLEGRIDY® (peginterferon beta-1a) is indicated for the treatment of relapsing forms of multiple sclerosis (MS), to include clinically isolated syndrome, relapsing-remitting disease, and active secondary progressive disease, in adults.

Important Safety Information

CONTRAINDICATIONS

  • PLEGRIDY® (peginterferon beta-1a) is contraindicated in patients with a history of hypersensitivity to natural or recombinant interferon beta or peginterferon, or any other component of the formulation

WARNINGS AND PRECAUTIONS

Hepatic Injury

  • Severe hepatic injury, including hepatitis, autoimmune hepatitis, and rare cases of severe hepatic failure, have been reported with interferon beta. Asymptomatic elevation of hepatic transaminases has also been reported, and in some patients has recurred upon rechallenge with interferon beta. Elevations in hepatic enzymes and hepatic injury have been observed with PLEGRIDY in clinical studies. Monitor liver function tests and patients for signs of hepatic injury. Consider discontinuation of PLEGRIDY if hepatic injury occurs. Cases of noninfectious hepatitis have been reported in the postmarketing setting with use of PLEGRIDY

Depression and Suicide

  • Depression, suicidal ideation, and suicide occur more frequently in patients receiving interferon beta than in patients receiving placebo. Advise patients to report immediately any symptom of depression or suicidal ideation. If a patient develops depression or other severe psychiatric symptoms, consider stopping treatment with PLEGRIDY

Anaphylaxis and Other Allergic Reactions

  • Serious allergic reactions are rare complications of treatment with interferon beta; anaphylaxis has been reported with use of PLEGRIDY in the postmarketing setting. Less than 1% of PLEGRIDY-treated patients experienced a serious allergic reaction such as angioedema or urticaria. Discontinue PLEGRIDY if a serious allergic reaction occurs. The rubber tip cap of the PLEGRIDY prefilled syringe for intramuscular administration contains natural rubber latex, which may cause allergic reactions and should not be handled by latex-sensitive individuals

Injection Site Reactions Including Necrosis

  • Injection site reactions, including injection site necrosis, can occur with the use of interferon beta, including PLEGRIDY. In clinical studies of subcutaneous PLEGRIDY, the incidence of injection site reactions (e.g., injection site erythema, pain, pruritus, or edema) was 66% in the PLEGRIDY group (3% were severe) and 11% in the placebo group (0% were severe). One patient out of 1468 patients who received PLEGRIDY experienced injection site necrosis. In a single clinical study of healthy volunteers comparing single doses of intramuscular and subcutaneous PLEGRIDY, the incidence of injection site reactions (e.g., injection site erythema, pain, pruritus, or edema) was 14% in the intramuscular PLEGRIDY group and 32% in the subcutaneous PLEGRIDY group. Injection site abscesses and cellulitis have been reported in the postmarketing setting with use of interferon beta. Some cases required treatment with hospitalization for surgical drainage and intravenous antibiotics

  • Periodically evaluate patient understanding and use of aseptic self-injection techniques and procedures, particularly if injection site necrosis has occurred. Decisions to discontinue therapy following necrosis at a single injection site should be based on the extent of the necrosis. For patients who continue therapy with PLEGRIDY after injection site necrosis has occurred, avoid administration of PLEGRIDY near the affected area until it is fully healed. If multiple lesions occur, change injection site or discontinue PLEGRIDY until healing occurs

Congestive Heart Failure

  • Congestive heart failure, cardiomyopathy, and cardiomyopathy with congestive heart failure occur in patients receiving interferon beta. The incidence of cardiovascular events was 7% in both PLEGRIDY and placebo treatment groups. Monitor patients with significant cardiac disease for worsening of their cardiac condition during initiation and continuation of treatment with PLEGRIDY

Decreased Peripheral Blood Counts

  • Interferon beta can cause decreased peripheral blood counts in all cell lines, including rare instances of pancytopenia and severe thrombocytopenia. Decreases in white blood cell counts below 3.0 x 109/L occurred in 7% of patients receiving PLEGRIDY and in 1% receiving placebo. The incidence of clinically significant decreases in lymphocyte counts (below 0.5 x 109/L), neutrophil counts (below 1.0 x 109/L), and platelet counts (below 100 x 109/L) were all less than 1% and similar in both placebo and PLEGRIDY groups. Monitor patients for infections, bleeding, and symptoms of anemia. Monitor complete blood cell counts, differential white blood cell counts, and platelet counts during treatment with PLEGRIDY. Patients with myelosuppression may require more intensive monitoring of blood cell counts

Thrombotic microangiopathy

  • Cases of thrombotic microangiopathy (TMA), including thrombotic thrombocytopenic purpura and hemolytic uremic syndrome, some fatal, have been reported several weeks to years after starting interferon beta products. Discontinue PLEGRIDY if clinical symptoms and laboratory findings consistent with TMA occur, and manage as clinically indicated

Pulmonary Arterial Hypertension

  • Cases of pulmonary arterial hypertension (PAH) have been reported in patients treated with interferon beta products, including PLEGRIDY. PAH has occurred in patients treated with interferon beta products in the absence of other contributory factors. Many of the reported cases required hospitalization, including one case with interferon beta in which the patient underwent a lung transplant. PAH has developed at various time points after initiating therapy with interferon beta products and may occur several years after starting treatment. Patients who develop unexplained symptoms (e.g., dyspnea, new or increasing fatigue) should be assessed for PAH. If alternative etiologies have been ruled out and a diagnosis of PAH is confirmed, discontinue treatment and manage as clinically indicated

Autoimmune disorders

  • Autoimmune disorders of multiple target organs including idiopathic thrombocytopenia, hyper- and hypothyroidism, and autoimmune hepatitis have been reported with interferon beta. The incidence of autoimmune disorders was less than 1% in both PLEGRIDY and placebo treatment groups. If patients develop a new autoimmune disorder, consider stopping PLEGRIDY

Seizures

  • Seizures are associated with the use of interferon beta. The incidence of seizures in clinical studies was less than 1% in patients receiving PLEGRIDY and placebo. Exercise caution when administering PLEGRIDY to patients with a seizure disorder

MOST COMMON SIDE EFFECTS

  • The most common adverse reactions in clinical trials of subcutaneous PLEGRIDY (incidence ≥10% and at least 2% more frequent on PLEGRIDY than on placebo) were injection site erythema, influenza-like illness, pyrexia, headache, myalgia, chills, injection site pain, asthenia, injection site pruritus, and arthralgia

Please see full Prescribing Information.

Start PLEGRIDY Getting Started Dosing Support program
Efficacy and Safety PLEGRIDY efficacy
Safety Well-established safety profile Adverse reactions Managing common side effects Special populations
Access and reimbursement

©2025 Biogen. All rights reserved. v10 03/25
All trademarks are the property of their respective owners.
For US healthcare professionals only.