The orally available active prodrug of ICRF-154, a bisdioxopiperazine derivative, with cardioprotective and antineoplastic activities. Like other ICRF compounds, sobuzoxane and its active metabolite ICRF-154 interfere with topoisomerase II activity prior to the formation of intermediate cleavable DNA-enzyme complexes during the catalytic cycle resulting in tumor cell growth inhibition. Furthermore, sobuzoxane chelates metal cations thereby limiting the formation of free radical-generating anthracycline-metal complexes and may prevent anthracycline-induced oxidative damage to cardiac and soft tissues.