ADA inversely related to dose (6/12, 3/12, 1/12 animals in 13-week study), reducing exposure and PD effect
“In the 13-week toxicology study, the incidence of ADA induction was inversely related to the dose: 6/12 animals at 10 mg/kg, 3/12 animals at 30 mg/kg, and 1/12 animals at 100 mg/kg.”
✓ VerifiedFDA multi-discipline review, p. 41Source ↗
Biodistribution & persistence
TCR conserved between human and monkey, consistent with CSF-1R expression including Kupffer cells and microglia
“In a GLP tissue cross-reactivity study, the observed antibody binding was well conserved between humans and cynomolgus monkey and concordant with the expected expression of CSF-1R in tissues, including liver Kupffer cells and microglia.”
✓ VerifiedFDA multi-discipline review, p. 37Source ↗
Modality-specific risk
Hepatic enzyme elevation with CSF-1R inhibition, seen in monkeys and in patients
“Hepatic enzyme elevation was observed in cynomolgus monkeys and in patients with solid tumors treated with axatilimab-csfr and other CSF-1R inhibitors.”
✓ VerifiedFDA multi-discipline review, p. 130Source ↗
Anti-drug antibodies: animals
13-week monkey study ADA inversely dose-related (6/12, 3/12, 1/12 at 10, 30, 100 mg/kg); ADA caused loss of exposure and PD effect
“In the 13-week toxicology study, the incidence of ADA induction was inversely related to the dose: 6/12 animals at 10 mg/kg, 3/12 animals at 30 mg/kg, and 1/12 animals at 100 mg/kg. The presence of ADAs correlated with the loss of exposure and PD effect (i.e., increase in CSF-1).”
✓ VerifiedFDA multi-discipline review, p. 41Source ↗
Anti-drug antibodies: patients
Treatment-emergent ADA in 33.7% (93/276) of cGVHD patients; neutralizing in 17.0%
“In clinical studies of axatilimab monotherapy, 93 of 276 assessable participants (33.7%) with cGVHD were treatment-emergent ADA-positive, and 47 participants (17.0%) were NAb-positive.”
✓ VerifiedFDA multi-discipline review, p. 163Source ↗
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