III. Contraindications

IV. Mechanism

  1. See Tumor Necrosis Factor Inhibitor
  2. Etanercept is a recombinant soluble Antibody against human Tumor Necrosis Factor alpha
    1. Etanercept has a unique structure among modern TNF Inhibitors which are primarily monoclonal antibodies
  3. Etanercept is a dimeric fusion Protein (2 components)
    1. Extracellular Ligand-binding region of TNF receptor
    2. Fc domain of Immunoglobulin G (IgG)
  4. Etanercept binds circulating TNF and inhibits TNF binding to TNF cell surface receptors
    1. Blocks TNF-mediated inflammatory activity

V. Medications

  1. Etanercept (Enbrel)
    1. Original prototype drug with release in 1998 for Rheumatoid Arthritis, with expanding indications since
  2. Multiple biosimilar agents (Erelzi, Eticovo) are available
    1. However, Biosimilars are not considered interchangeable (consistently use same agent)

VI. Dosing

  1. See Monoclonal Antibody for preparation for use
  2. Background
    1. Injection sites include thigh, Abdomen or upper, outer arm (rotate injection sites)
    2. Available as a Preloaded vial or syringe
    3. Refrigerate and protect from light
    4. Stable at room Temperature for up to 14 days
    5. Allow to warm to room Temperature for 15 to 30 minutes before injection (decreased pain)
  3. Rheumatoid Arthritis, Psoriatic Arthritis or Ankylosing Spondylitis
    1. Inject 50 mg SQ weekly
  4. Plaque Psoriasis
    1. Start 50 mg SQ twice weekly for 3 months
    2. Next 50 mg SQ weekly
  5. Child (weight <63 kg)
    1. Indicated in Juvenile Idiopathic Arthritis (age >2 years) and plaque Psoriasis (age >4 years)
    2. Use adult dosing for weight >=63 kg
    3. Inject 0.8 mg/kg SQ weekly

VII. Precautions

  1. See TNF Inhibitor
  2. TNF Inhibitors predispose to serious infections and malignancy
  3. Prepare for TNF Inhibitor use with infection screening (e.g. Tuberculosis) and Immunizations
    1. See Monoclonal Antibody

VIII. Efficacy

  1. Rapid onset and very effective
  2. Arrests XRay progression
  3. Good synergistic effect with Methotrexate

IX. Adverse Effects

  1. See Tumor Necrosis Factor Inhibitor
  2. Potential risk of infection
  3. No significant adverse effects

X. Safety

  1. Considered safe in Lactation
  2. Pregnancy
    1. May use in pregnancy (any trimester) if indicated and benefit outweighs risk
    2. Fetal exposure risk increases after 20 weeks

XI. Pharmacokinetics

  1. Metabolism by proteolysis

XII. Monitoring

  1. Consider following Complete Blood Count

XIV. References

  1. (2023) Biologics for Crohn's Disease, Presc Lett, #390826
  2. (2023) Drugs for Inflammatory Bowel Disease, Med Lett Drug Ther 65: 105-12
  3. Bathon (2000) N Engl J Med 343:1586-93 [PubMed]
  4. Weinblatt (1999) N Engl J Med 340: 253-9 [PubMed]

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Related Studies

Cost: Medications

enbrel (on 7/1/2022 at Medicaid.Gov Survey of pharmacy drug pricing)
ENBREL 25 MG/0.5 ML SYRINGE $1,597.43 per ml
ENBREL 50 MG/ML MINI CARTRIDGE $1,596.93 per ml
ENBREL 50 MG/ML SURECLICK $1,599.63 per ml
ENBREL 50 MG/ML SYRINGE $1,596.90 per ml