Immunosuppression and severe infections from lymphocyte depletion limited achievable exposure margins
“evaluating doses corresponding to a 10-fold exposure margin when compared to the exposure in the MS patients would not be feasible due to immunosuppression and severe infections.”
ADA in the majority of animals tested; no significant influence on pharmacokinetics
“Anti-alemtuzumab antibodies were detected in the majority of the animals tested. However, the presence of anti-alemtuzumab antibodies was not considered by the CHMP to have any significant influence on the alemtuzumab pharmacokinetics in the studies conducted.”
8.3% (11/133) of previously untreated patients had anti-human antibodies; two weakly neutralizing
“Using an ELISA assay, anti-human antibodies (HAHA) were detected in 11 of 133 (8.3%) previously untreated patients. In addition, two patients were weakly positive for neutralizing activity.”
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