Embryo‐fetal developmental toxicity of figitumumab, an anti‐insulin‐like growth factor‐1 receptor (IGF‐1R) monoclonal antibody, in cynomolgus monkeys

Abstract

Maternal figitumumab dosing only during the period of organogenesis was associated with pregnancy loss and fetal growth deficits; both considered consistent with inhibition of IGF signaling. Fetal malformations were also observed, and were considered secondary to altered placental function and/or reduced fetal growth; however, direct inhibition of IGF signaling in the conceptus cannot be ruled out. This appears to be the first report of treatment-related fetal anomalies with a monoclonal antibody when administered only during the period of major organogenesis.