Low cytokine release syndrome risk in human whole-blood cytokine assay
“Based on a human in vitro blood cytokine assay, the potential of satralizumab to induce a cytokine release syndrome (CRS) is considered to be low in terms of incidence and increase in cytokines.”
TCR: similar human and monkey staining consistent with IL-6R expression (adrenal, liver, macrophages, lymphocytes)
“The staining pattern produced was consistent with what is known regarding IL-6R expression in e.g. adrenal cells, liver, macrophages, and lymphocytes, and the staining pattern was similar in human and Cynomolgus monkey tissue.”
Immunosuppression from IL-6R blockade: impaired antibody responses in exposed infants (infection, vaccine response risk)
“However, infants of women treated with satralizumab during pregnancy may be at increased risk of adverse effects such as infection or impaired response to vaccinations.”
✓ VerifiedFDA pharmacology/toxicology review, p. 7Source ↗
Anti-drug antibodies: animals
ADA in 12-22% of monkeys, some neutralizing, often with reduced exposure (excluded from TK); study validity retained
“ADAs development was commonly seen in the studies in monkey (overall incidence of 12-22%), and some animals showed neutralization activity. These animals often showed reduced exposure to satralizumab and were excluded in the TK calculations.”
73% (Study 1) and 38% (Study 2) in double-blind period; neutralizing ability unknown
“In Study 1 and Study 2, anti-drug-antibodies (ADAs) were observed in 73% and 38% of patients receiving ENSPRYNG in the double-blind period, respectively. The ability of these ADAs to neutralize satralizumab-mwge binding is unknown.”
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