A randomized phase l pharmacokinetic study comparing SB4 and etanercept reference product (Enbrel®) in healthy subjects

Br J Clin Pharmacol. 2016 Jul;82(1):64-73. doi: 10.1111/bcp.12929. Epub 2016 May 2.


Aims: SB4 has been developed as a biosimilar of etanercept. The primary objective of the present study was to demonstrate the pharmacokinetic (PK) equivalence between SB4 and European Union -sourced etanercept (EU-ETN), SB4 and United States-sourced etanercept (US-ETN), and EU-ETN and US-ETN. The safety and immunogenicity were also compared between the treatments.

Methods: This was a single-blind, three-part, crossover study in 138 healthy male subjects. In each part, 46 subjects were randomized at a 1:1 ratio to receive a single 50 mg subcutaneous dose of the treatments (part A: SB4 or EU-ETN; part B: SB4 or US-ETN; and part C: EU-ETN or US-ETN) in period 1, followed by the crossover treatment in period 2 according to their assigned sequences. PK equivalence between the treatments was determined using the standard equivalence margin of 80-125%.

Results: The geometric least squares means ratios of AUCinf , AUClast and Cmax were 99.04%, 98.62% and 103.71% (part A: SB4 vs. EU-ETN); 101.09%, 100.96% and 104.36% (part B: SB4 vs. US-ETN); and 100.51%, 101.27% and 103.29% (part C: EU-ETN vs. US-ETN), respectively, and the corresponding 90% confidence intervals were completely contained within the limits of 80-125 %. The incidence of treatment-emergent adverse events was comparable, and the incidence of the antidrug antibodies was lower in SB4 compared with the reference products.

Conclusions: The present study demonstrated PK equivalence between SB4 and EU-ETN, SB4 and US-ETN, and EU-ETN and US-ETN in healthy male subjects. SB4 was well tolerated, with a lower immunogenicity profile and similar safety profile compared with those of the reference products.

Keywords: SB4; biosimilar; etanercept; immunogenicity; pharmacokinetics; safety.

Publication types

  • Clinical Trial, Phase I
  • Comparative Study
  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Antibodies / immunology
  • Antirheumatic Agents / administration & dosage*
  • Antirheumatic Agents / adverse effects
  • Antirheumatic Agents / pharmacokinetics
  • Area Under Curve
  • Biosimilar Pharmaceuticals / administration & dosage*
  • Biosimilar Pharmaceuticals / adverse effects
  • Biosimilar Pharmaceuticals / pharmacokinetics
  • Cross-Over Studies
  • Etanercept / administration & dosage*
  • Etanercept / adverse effects
  • Etanercept / pharmacokinetics
  • European Union
  • Humans
  • Least-Squares Analysis
  • Male
  • Middle Aged
  • Single-Blind Method
  • Therapeutic Equivalency
  • United States


  • Antibodies
  • Antirheumatic Agents
  • Biosimilar Pharmaceuticals
  • Etanercept