Predicted biologic activity of intravitreal bevacizumab

Retina. 2007 Nov-Dec;27(9):1196-200. doi: 10.1097/IAE.0b013e318158ea28.


Purpose: To create a time- and dose-dependent mathematical model that compares the intravitreal vascular endothelial growth factor (VEGF) binding activity of bevacizumab with that of ranibizumab.

Methods: Intravitreal half-lives and relative equimolar VEGF binding activities of bevacizumab and ranibizumab were incorporated into a first-order decay model. Time-dependent bevacizumab activities (relative to ranibizumab) for different initial doses (1.25 and 2.5 mg) and reinjection intervals (single, weekly, and every 3 days) were calculated and graphed.

Results: Twenty-seven days to 38 days after a single bevacizumab (1.25 mg) injection, the intravitreal VEGF binding activity would be comparable with that of ranibizumab at 30 days. Bevacizumab (2.5 mg) injections would need to be performed every 3 days for 1 month to equal the peak activity after a ranibizumab injection.

Discussion: On the basis of this mathematical model, intravitreal bevacizumab maintains significant VEGF binding activity for 4 weeks to 5 weeks. More frequent bevacizumab injections increase the average binding activity but not to that seen with a single ranibizumab injection.

MeSH terms

  • Absorption
  • Angiogenesis Inhibitors / administration & dosage
  • Angiogenesis Inhibitors / pharmacokinetics*
  • Antibodies, Monoclonal / administration & dosage
  • Antibodies, Monoclonal / pharmacokinetics*
  • Antibodies, Monoclonal, Humanized
  • Bevacizumab
  • Biological Availability
  • Half-Life
  • Humans
  • Injections
  • Models, Theoretical*
  • Ranibizumab
  • Time Factors
  • Vascular Endothelial Growth Factor A / metabolism*
  • Vitreous Body / metabolism*


  • Angiogenesis Inhibitors
  • Antibodies, Monoclonal
  • Antibodies, Monoclonal, Humanized
  • Vascular Endothelial Growth Factor A
  • Bevacizumab
  • Ranibizumab