Absence of adverse effects in cynomolgus macaques treated with CNTO 95, a fully human anti-alphav integrin monoclonal antibody, despite widespread tissue binding.

PURPOSE: CNTO 95 is a fully human anti-alphav integrin monoclonal antibody that inhibits macaque and rodent angiogenesis and inhibits human tumor growth in rodents. The purpose of these studies was to evaluate the preclinical safety of long-term administration of CNTO 95 in cynomolgus macaques. EXPERIMENTAL
DESIGN: The in vitro binding profiles of CNTO 95 to human and macaque tissues and the in vivo binding to macaque tissues was evaluated by immunohistochemistry. The preclinical safety of CNTO 95 (10 and 50 mg/kg, i.v.) was evaluated in macaques treated once per week for up to 6 months. Safety was evaluated by clinical observations, ophthalmic and physical examinations (including heart rate, blood pressure, and electrocardiogram), clinical pathology (including coagulation parameters), and comprehensive anatomic pathology. The effect of CNTO 95 (50 mg/kg, i.v.) on incisional wound healing was evaluated in macaques.
RESULTS: The tissue binding studies showed that CNTO 95 bound with mild to moderate intensity to macaque and human endothelial cells, epithelial cells, and vascular smooth muscle cells in most normal tissues examined. CNTO 95 showed strong to intense staining to the positive control tissue, human placenta. Despite the widespread binding to normal tissues, treatment of cynomolgus macaques with CNTO 95 produced no signs of toxicity and no histopathologic changes in any of the tissues examined (including ovaries and bone growth plates). CNTO 95 did not impair wound healing.
CONCLUSION: These studies show that CNTO 95 is safe and, unlike some other angiogenesis inhibitors, does not seem to inhibit normal physiologic angiogenesis.