Interferon alfacon-1

Summary

Interferon alfacon-1 (Infergen) is a synthetic consensus type I interferon engineered by scanning all known natural interferon-alpha subtypes and assigning the most frequently occurring amino acid at each position. It was approved for treatment of chronic hepatitis C virus (HCV) infection. It was withdrawn from the US market in 2013, largely due to competition from more effective direct-acting antiviral therapies for HCV.

Mechanism of Action

Binds to type I interferon receptors (IFNAR1/IFNAR2) on cell surfaces, activating the JAK-STAT signaling pathway (JAK1/TYK2), leading to transcription of interferon-stimulated genes (ISGs) that encode antiviral proteins, immunomodulatory factors, and antiproliferative effectors. Results in enhanced natural killer cell activity, upregulation of MHC class I expression, and inhibition of viral replication.

Routes of Administration

Goals & Uses

• Chronic Hepatitis C treatmentAntiviralHigh
• Hepatitis C re-treatment (non-responders/relapsers)AntiviralModerate
• Antiproliferative / oncology (investigational)OncologyLow
• Antiviral activity (broad)AntiviralLow

Contraindications

• PregnancyPopulationHighPotential fetal risk or insufficient safety data
• Autoimmune hepatitisHepatic / AutoimmuneHigh
• Decompensated liver diseaseHepatic ImpairmentHigh
• Hypersensitivity to interferon alfacon-1 or E. coli-derived productsImmunologicHigh
• Severe bone marrow suppressionHematologicHigh
• Severe psychiatric disorders (untreated)PsychiatricHigh

Adverse Effects

• Flu-like symptoms (fever, chills, myalgia, headache)SystemicCommon
• Injection site reactionsLocalCommon
• ThrombocytopeniaHematologicCommonLow platelet count
• Thyroid dysfunction (hypothyroidism or hyperthyroidism)EndocrineUncommon
• Depression and suicidal ideationPsychiatricCommon
• Neutropenia / leukopeniaHematologicCommon

Drug Interactions

• Immunosuppressive agents (e.g., cyclosporine, tacrolimus)Moderate
• RibavirinModerate
• Theophylline / CYP1A2 substratesModerate
• Myelosuppressive agents (e.g., azathioprine, hydroxyurea)High

Population Constraints

• Pediatric patients (<18 years)AgeRelative
• Patients with active substance use disorderBehavioralRelative
• Patients with cardiac diseaseCardiovascularRelative
• Patients with renal impairmentOrgan ImpairmentRelative
• Elderly patients (>65 years)AgeRelative

Regulatory Status

• European UnionUnknownInfergen was not widely approved or marketed in the EU under centralized procedures; regulatory status uncertain.
• United StatesWithdrawnApproved: Chronic hepatitis C virus (HCV) infection in adults with compensated liver diseaseApproved by FDA in 1997 (NDA 020528); voluntarily withdrawn from market in 2013 by AstraZeneca due to commercial reasons and competition from direct-acting antivirals.
• United KingdomUnknownNot known to have had a separate UK marketing authorization; market withdrawal likely paralleled US status.

FDA approved in 1997 (NDA 020528) for chronic HCV infection. Voluntarily withdrawn from the US market by AstraZeneca in 2013. Not currently approved or actively marketed in major jurisdictions.

Evidence & Sources

No sources recorded yet.