Etoposide phosphate disodium (BMY-40481 disodium), a phosphate ester prodrug of etoposide, functions as a potent chemotherapeutic agent by selectively inhibiting topoisomerase II, hindering the re-ligation of DNA strands. It is regarded as the active equivalent of etoposide, effectively inducing cell cycle arrest, apoptosis, and autophagy in cancer cells.