TY - JOUR T1 - Predicted biological activity of intravitreal VEGF Trap JF - British Journal of Ophthalmology JO - Br J Ophthalmol SP - 667 LP - 668 DO - 10.1136/bjo.2007.134874 VL - 92 IS - 5 AU - M W Stewart AU - P J Rosenfeld Y1 - 2008/05/01 UR - http://bjo.bmj.com/content/92/5/667.abstract N2 - Aim: To compare the intravitreal binding activity of VEGF Trap with that of ranibizumab against vascular endothelial growth factor (VEGF) using a time-dependent and dose-dependent mathematical model.Methods: Intravitreal half-lives and relative equimolar VEGF-binding activities of VEGF Trap and ranibizumab were incorporated into a first-order decay model. Time-dependent VEGF Trap activities (relative to ranibizumab) for different initial doses (0.5, 1.15, 2 and 4 mg) were calculated and plotted.Results: Seventy-nine days after a single VEGF Trap (1.15 mg) injection, the intravitreal VEGF-binding activity would be comparable to ranibizumab at 30 days. After injection of 0.5, 2 and 4 mg VEGF Trap, the intravitreal VEGF-binding activities (comparable to ranibizumab at 30 days) would occur at 73, 83 and 87 days, respectivelyConclusion: On the basis of this mathematical model, VEGF Trap maintains significant intravitreal VEGF-binding activity for 10–12 weeks after a single injection. ER -