In vitro ADCC with nude rat effector cells ~22% vs 55% with human NK cells, underpredicting human activity
“Naxitamab induced approximately 22% ADCC in human LAN-1/rat splenocyte co-cultures whereas there was 55% ADCC against the same cell line in the presence of human NK cells, indicating that the rat/rat and rat/human systems underpredicted the activity of the human/human system.”
✓ VerifiedFDA multi-discipline review, p. 41Source ↗
Biodistribution & persistence
TCR: on-target binding to peripheral nerve, cerebellum, spinal cord, frontal lobe and pons
“FDA agrees that tissue cross reactivity studies showed binding to peripheral nerve, cerebellum, spinal cord, frontal lobe, and pons.”
✓ VerifiedFDA multi-discipline review, p. 56Source ↗
Modality-specific risk
Neuropathic pain from binding GD2 on peripheral nerve fibers and myelin with immune-mediated cytotoxicity
“Non-clinical studies suggest that naxitamab-gqgk-induced neuropathic pain is mediated by binding of the antibody to the GD2 antigen located on the surface of peripheral nerve fibers and myelin and subsequent induction of immune-mediated cytotoxic activity.”
“Investigators reasoned that the use of nude rats rather than fully immune competent animals would allow for avoidance of the formation of anti-drug antibodies that would prevent long-term assessment of a human antibody in a rodent model.”
✓ VerifiedFDA multi-discipline review, p. 41Source ↗
Anti-drug antibodies: patients
8% (2/24) in Study 201; 23% (27/117) in Study 12-230 with a not fully validated assay
“In Study 201, 2 of 24 (8%) patients tested positive for anti-drug antibodies (ADA) after treatment with DANYELZA. In Study 12-230, 27 of 117 patients (23%) tested positive for ADA after treatment with DANYELZA by an assay that was not fully validated”
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