ADA-driven shock-like reactions with complement activation and immune complexes in some monkeys
“In some toxicity studies shock-like reactions with complement activation and the formation of immune complexes due to high levels of anti-natalizumab antibodies were described in some cynomolgus monkeys.”
ADA in almost all monkeys within 2-4 weeks; apparently neutralising titres up to 1600 µg/ml
“Antigenicity was detected in almost all animals within 2-4 weeks depending on the administered dose of natalizumab that is interfering with the anti-natalizumab antibodies detection assays. High titres of apparently neutralising anti-natalizumab antibodies up to 1600µg/ml are induced in cynomolgus monkeys.”
HAHA incidence 10% in phase III; persistent ADA in ~6% of MS patients over 2 years
“After repeat infusions the HAHA incidence was reduced to 12%, and in the phase III studies to 10%. In 2-year controlled clinical trials in MS patients, persistent anti-natalizumab antibodies (one positive test reproducible on retesting at least 6 weeks later) developed in approximately 6% of patients.”
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