SN22

**SN22** is a synthetic camptothecin analog and potent **topoisomerase I inhibitor** optimized for anticancer activity, particularly against high-risk neuroblastoma. It promotes death of rapidly dividing tumor cells by stabilizing the topoisomerase I-DNA cleavage complex, preventing DNA religation and causing lethal double-strand breaks. Unlike irinotecan or topotecan, SN22 evades efflux transporters, enabling superior tumor penetration and retention, while minimizing dose-limiting toxicities like diarrhea. Developed by researchers at Children's Hospital of Philadelphia (CHOP), it is delivered as polymer-linked prodrugs (e.g., PEEL-224 with PEG or Poloxamer/Pluronic carriers) to enhance circulation time, tumor uptake, and sustained exposure, achieving complete tumor regression in preclinical models of MYCN-amplified and chemoresistant neuroblastoma.[2][4][5]

Other names

7-ethyl Camptothecin(S)-4,11-diethyl-4-hydroxy-1H-pyrano[3',4':6,7]indolizino[1,2-b]quinoline-3,14(4H,12H)-dione