Preclinical safety evaluation of intravitreal injection of full-length humanized vascular endothelial growth factor antibody in rabbit eyes.
OBJECTIVE
To evaluate the preclinical safety of intravitreal bevacizumab, which is a full-length humanized monoclonal antibody against the vascular endothelial growth factor (VEGF), in rabbit eyes over a short-term period.


METHODS
Twenty-four rabbits were divided into two groups, each with two subgroups. The first group (groups 1 and 2) received 1.25 mg (0.05 mL) intravitreal bevacizumab, and the second group (groups 3 and 4) received 3.00 mg (0.12 mL) intravitreal bevacizumab. The right eyes were designated as the study eyes, and the left eyes served as a control and received the same volume of saline intravitreally. Groups 1 and 3 were labeled as early groups and scheduled to be terminated at 14 days. Groups 2 and 4, labeled as late groups, were scheduled to be terminated at 28 days. Besides electroretinography (ERG) and visually evoked potentials (VEP), central corneal thickness, intraocular pressure, fundus photography, and anterior segment imaging were performed at baseline and scheduled time points. Enucleated eyes were preserved for light and electron microscopic investigation.


RESULTS
No anterior segment inflammation was observed, except in one eye in group 1 which showed a uveitic reaction. No evidence of retinal toxicity was seen with intravitreal bevacizumab at doses of 1.25 and 3.00 mg, by either ERG or light microscopy. Electron microscopic assessment revealed mitochondrial damage in the inner segments of photoreceptors. Immunohistochemical staining with bax and caspase-3 and -9 showed intensive apoptotic protein expression in all study sections and minimal expression in the control eyes.


CONCLUSIONS
Although electrophysiologic investigation and light microscopy showed normal retinal function and structure, mitochondrial disruption in the inner segments of photoreceptors was detected by electron microscopy, and apoptotic expression was detected after the injection of intravitreal bevacizumab.
Inan
Umit Ubeyt
UU
Department of Ophthalmology, Kocatepe University School of Medicine, 03200 Afyon, Turkey. uinan@aku.edu.tr
Avci
Berrin
B
Kusbeci
Tuncay
T
Kaderli
Berkant
B
Avci
Remzi
R
Temel
Sehime G
SG
D020533:Angiogenesis Inhibitors / Q000008:administration & dosage* / Q000633:toxicity; D000818:Animals; D000869:Anterior Eye Segment / Q000187:drug effects / Q000473:pathology; D000911:Antibodies, Monoclonal / Q000008:administration & dosage* / Q000633:toxicity; D061067:Antibodies, Monoclonal, Humanized; D000068258:Bevacizumab; D053148:Caspase 3 / Q000378:metabolism; D053453:Caspase 9 / Q000378:metabolism; D004353:Drug Evaluation, Preclinical; D004596:Electroretinography / Q000187:drug effects; D005074:Evoked Potentials, Visual / Q000187:drug effects; D007267:Injections; D007429:Intraocular Pressure / Q000187:drug effects; D008297:Male; D008928:Mitochondria / Q000187:drug effects / Q000378:metabolism / Q000648:ultrastructure; D011817:Rabbits; D012160:Retina / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D042461:Vascular Endothelial Growth Factor A / Q000276:immunology*; D014822:Vitreous Body; D051028:bcl-2-Associated X Protein / Q000378:metabolism
D020533:Angiogenesis Inhibitors; D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A; D051028:bcl-2-Associated X Protein; D000068258:Bevacizumab; D053148:Caspase 3; D053453:Caspase 9