Human TCR: expected staining of lymphocytes and epithelial cells consistent with IL-36R expression; no tissue distribution studies
“Spesolimab stained lymphocytes in tonsil epithelial cells in a variety of tissues, which was considered expected based on previous data and literature on IL-36R expression.”
Infection risk (IL-36 pathway in epithelial host defence) and potential reduced cancer immunosurveillance
“Given the expression of the IL36R in epithelium of various tissues including skin and lung, and as the IL36 pathway has been implicated in host-defence, spesolimab treatment may be expected to increase the risk for serious, severe or opportunistic infections.”
26-week mouse surrogate study: ADA in 4 of 17 samples (10 mg/kg/dose) and 3 of 23 (50 mg/kg/dose)
“Anti-drug antibody (ADA) was detected in 4 of 17 samples at 10 mg/kg/dose and 3 of 23 samples at 50 mg/kg/dose.”
✓ VerifiedFDA multi-discipline review, p. 35Source ↗
Anti-drug antibodies: patients
GPP (IV): ADA in 46% by Week 12-17; 24% had titers >4000 with decreased exposure
“In GPP patients treated with IV spesolimab, anti-drug antibodies (ADAs) were formed in 46% of patients by Week 12-17 with a median onset of 2.3 weeks. Among ADA-postitive patients, those with ADA titer values greater than 4000 (24%), were observed to have significantly decreased plasma spesolimab concentrations from Week 3 onward.”
✓ VerifiedFDA multi-discipline review, p. 43Source ↗
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