Peginterferon alfa-2b

Summary

Peginterferon alfa-2b (brand name PegIntron/Sylatron) is a pegylated form of recombinant interferon alfa-2b with extended half-life due to polyethylene glycol conjugation. It is FDA-approved for chronic hepatitis C (in combination with ribavirin) and as adjuvant therapy for melanoma following surgical resection. Pegylation reduces renal clearance and immunogenicity, allowing once-weekly dosing.

Mechanism of Action

Peginterferon alfa-2b is a pegylated recombinant interferon alfa-2b that binds to type I interferon receptors (IFNAR1/IFNAR2) on cell surfaces, activating the JAK-STAT signaling pathway (primarily JAK1 and TYK2), leading to upregulation of interferon-stimulated genes (ISGs). This results in antiviral, antiproliferative, and immunomodulatory effects, including enhanced NK cell activity, macrophage phagocytosis, and MHC class I expression.

Routes of Administration

Goals & Uses

• Chronic Hepatitis C treatmentAntiviralHigh
• Antiproliferative effect in hematologic malignanciesOncologyModerate
• Adjuvant melanoma therapyOncologyHigh
• Antiviral ImmunomodulationImmunologyModerate

Contraindications

• Severe psychiatric disorders (uncontrolled)PsychiatryHigh
• Hypersensitivity to interferon alfa or PEGImmunologicHigh
• Decompensated liver disease (Child-Pugh B/C)HepaticHigh
• PregnancyPopulationHighPotential fetal risk or insufficient safety data
• Neonates and Infants (benzyl alcohol-containing formulations)PediatricHigh
• Autoimmune hepatitisHepatic / AutoimmuneHigh

Adverse Effects

• Neuropsychiatric effects (depression, irritability, suicidal ideation)PsychiatricCommon
• Injection site reactionsLocalCommon
• Flu-like symptoms (fever, chills, myalgia, fatigue)Systemic / ConstitutionalCommon
• Myelosuppression (neutropenia, thrombocytopenia, anemia)HematologicCommon
• Retinopathy and optic neuropathyOphthalmologicRare
• Thyroid dysfunction (hypo- or hyperthyroidism)EndocrineUncommon

Drug Interactions

• Myelosuppressive agents (e.g., azathioprine, chemotherapy)High
• Immunosuppressants (e.g., cyclosporine)Moderate
• RibavirinModerate
• MethadoneModerate
• Theophylline / CYP1A2 substratesModerate

Population Constraints

• Psychiatric historyNeuropsychiatricRelative
• PregnancyReproductive SafetyAbsolute
• Renal impairment (CrCl <50 mL/min)RenalRelative
• Elderly (≥65 years)GeriatricRelative
• Pediatric patients (<3 years)PediatricAbsolute

Regulatory Status

• European UnionApprovedApproved: Chronic hepatitis C (combination with ribavirin or as monotherapy), Adjuvant melanoma (in some EU member states)EMA-approved; ViraferonPeg is the brand name in Europe. Some indications have been voluntarily withdrawn or updated as DAAs gained prominence.
• United StatesApprovedApproved: Chronic hepatitis C (in combination with ribavirin, genotypes 2 and 3, or as monotherapy), Adjuvant treatment of melanoma with microscopic or gross nodal involvement within 84 days of definitive surgical resection (Sylatron)PegIntron approved in 2001; Sylatron approved in 2011. HCV indication largely superseded by DAAs but remains approved.
• United KingdomApprovedApproved: Chronic hepatitis C, Adjuvant melanoma (post-Brexit, MHRA authorization)MHRA-approved post-Brexit; use in HCV now limited due to DAA availability on NHS.

FDA-approved; EMA-approved. Hepatitis C indication has become less prominent with the advent of direct-acting antivirals (DAAs). Sylatron formulation approved by FDA in 2011 for adjuvant melanoma treatment.

Evidence & Sources

No sources recorded yet.