Comparative effects of bevacizumab, ranibizumab and pegaptanib at intravitreal dose range on endothelial cells

Anti-VEGF therapy proved to be useful against several ocular pathological situations, including choroidal neovascularization and proliferative retinopathies. Ranibizumab (Ran), Pegaptanib (Peg) and Bevacizumab (Bev) are the pharmacological agents more frequently used in clinical practice by intravitreal injection. However, their exact effects on the angiogenic process have not been accurately established in a comparative study. The aim of the present study was to elucidate the precise effects of Ran, Peg and Bev on the multiple steps of the angiogenic process. Human umbilical vein endothelial cells (HUVEC) were incubated with each agent within the clinically established concentration range, or identical amounts of the excipients; cell cytotoxicity, proliferation, apoptosis, migration and vessel assembly were assessed. No cytotoxic effects were found for any of the agents studied at any concentration tested. At the clinical dose, cell proliferation was significantly reduced by Bev and Ran, whereas no difference was observed after Peg treatment. In addition, HUVEC apoptosis was effectively increased by Bev and Ran. Cell migration was reduced after incubation with every agent analyzed, though only reaching statistical significance upon Ran intravitreal dose. At clinical doses, capillary assembly was only affected by Bev. In agreement with these data, the active form of VEGF receptor-2 expression was decreased after incubation with Bev (to 66% of control values), Ran (78%) and Peg (86%) relative to controls. These findings indicate that these three agents display distinct effects on endothelial cells.