Generally not immunogenic in monkeys; ADA in 12% including weak responders
“Ipilimumab generally was not immunogenic in monkeys. When including the animals with a weak antibody response, a value of 12% was calculated for the frequency of anti-ipilimumab-Ab positive animals.”
TCR: binding to activated lymphocytes expressing CTLA-4 in human and monkey tissues, and to placental connective tissue
“In tissue cross-reactivity studies, ipilimumab specifically bound to activated lymphocytes expressing CTLA-4 in several normal human and/or cynomolgus monkey tissues. In addition, ipilimumab bound specifically to connective tissue in human and cynomolgus monkey placenta and to connective tissue in cynomolgus monkey ovary; no specific binding was observed in human ovary.”
Immune-related adverse events (colitis, dermatitis) from CTLA-4 blockade; no safety margin determined
“The most notable concern identified during non-clinical testing was a low incidence of serious irAEs, manifested as colitis or dermatitis, for which no safety margin could be determined.”
In vitro whole-blood cytokine release far below alemtuzumab/TGN1412 controls; no effects on monkey TDAR, lymphocyte subsets or serum cytokines; ADA in some monkeys