ADA in all monkeys at all doses in 13-week study, reducing low-dose exposure; reduced thymic/lymphoid cellularity
“Anti-drug antibodies were detected in all animals at all doses tested in the chronic toxicity study.”
✓ VerifiedFDA multi-discipline review, p. 176Source ↗
Biodistribution & persistence
Mouse xenograft: radiolabeled ADC to tumour plus liver, spleen, kidney, lung; SN-38 released in serum (t1/2 ~1-2 days); free SN-38 ~2.3% of total
“In addition to tumour, both hRS7 and sacituzumab govitecan distributed to normal tissues, primarily to liver, spleen, kidney and lungs among the normal tissues analysed.”
SN-38 payload myelosuppression and GI toxicity (UGT1A1-dependent), Trop-2-dependent skin toxicity; hydrolysable linker releases payload
“Findings in the gastrointestinal tract and reductions in white blood cells are known toxicities of irinotecan-derived SN-38. Findings in skin may represent Trop-2-dependent toxicity.”