tirapazamine
DrugTirapazamine is a benzotriazine with selective cytotoxicity for hypoxic cells. Under hypoxic conditions, it undergoes a 1-electron reduction to form a cytotoxic free radical that poisons topoisomerase II and causes DNA breaks, chromosomal aberrations, and cell death.
Tirapazamine was administered on Days 1 and 22 prior to the administration of neoadjuvant cisplatin and on Days 43, 45, 47, 71, 73, and 75 within 1 or 2 hours prior to each simultaneous cisplatin dose.
Tirapazamine dose was as follows:
Level 1 - 300 mg/m2 during the induction phase and 160 mg/m2 during the simultaneous phase (n = 4)
Level 2 - 330 mg/m2 during the induction phase and 260 mg/m2 during the simultaneous phase (n = 4)
Level 3 - 300 mg/m2 during the induction phase and 220 mg/m2 during the simultaneous phase (n = 25)
Other names: Tirazone, TPZ, SR 4233, 3-amino-1,4-benzotriazine-1-N-oxide, WIN 59074