A synthetic silicon-containing agent related to camptothecin with antineoplastic properties. Cositecan stabilizes the cleavable complex between topoisomerase I and DNA, resulting in DNA breaks and consequently triggering apoptosis. Because it is lipophilic, karenitecin exhibits enhanced tissue penetration and bio-availability compared to water-soluble camptothecins. or A drug being studied in the treatment of cancer. It is a type of topoisomerase inhibitor. It is related to the anticancer drug camptothecin.