etoposide toniribate

A prodrug of etoposide, a semisynthetic derivative of podophyllotoxin extracted from the mandrake root Podophyllum peltatum, with potential antineoplastic activity. Upon intravenous administration of etoposide toniribate, etoposide is released after enzymatic cleavage of CAP7.1 by specific carboxylesterases (CE) 1 and 2, which are upregulated in certain tumor cell types. Etoposide acts primarily in the G2 and S phases of the cell cycle. This drug binds to and inhibits topoisomerase II, an enzyme elevated in tumor cells. This results in the accumulation of double-strand DNA breaks, the inhibition of DNA replication and transcription and the induction of apoptotic cell death. The tumor-specific activation of etoposide increases its efficacy while lowering its systemic toxicity.