Abstract
Purpose: :
To monitor VEGF 165 serum levels in patients with neovascular age–related macular degeneration (AMD) treated with intravenous Bevacizumab (Avastin®).
Methods: :
15 patients received 3 infusions of either 5mg/kg or 2,5mg/kg of bevacizumab at two week intervals. VEGF 165 serum levels were determined by Enzyme–Linked Immunosorbent Assay (ELISA) at baseline and at 1, 2, 3 and 6 months follow–up.
Results: :
In every single patient VEGF 165 serum levels were determinable. All patients showed decreased VEGF 165 serum levels after the first bevacizumab infusion. A 50% VEGF 165 serum level reduction was seen after 4 weeks compared to baseline level. The third infusion did not induce a further reduction in VEGF 165 serum levels. VEGF 165 serum levels started rising again at month 3 and reached about baseline levels at month 6.
Conclusions: :
Systemic bevacizumab therapy reduced VEGF 165 serum levels for at least 3 months, which may explain the long treatment durability in patients with neovascular AMD. Monitoring VEGF 165 serum levels could become useful tool in monitoring patients at risk for recurrent neovascular AMD and in optimizing the treatment regimen.
Keywords: age-related macular degeneration • growth factors/growth factor receptors • clinical laboratory testing