Purpose: Tumor hypoxia confers chemotherapy resistance. Tirapazamine is a cytotoxin that selectively targets hypoxic cells. We conducted a phase III clinical trial to determine whether the addition of tirapazamine to paclitaxel and carboplatin offered a survival advantage when used in the treatment of patients with advanced non-small-cell lung cancer (NSCLC). Patients and Methods: Of 396 patients registered, 367 eligible patients were randomly assigned to either arm 1 (n = 181), which consisted of treatment every 21 days with paclitaxel 225 mg/m2/3 h, carboplatin (area under the curve = 6), and tirapazamine 260 mg/m2 in cycle 1 (which was escalated, if tolerable, to 330 mg/m2 in cycle 2), or arm 2 (n = 186), which consisted of paclitaxel and carboplatin as in arm 1 with no tirapazamine. Results: Patient characteristics were similar between the two arms. There were no statistically significant differences in response rates, progression-free survival, or overall survival. Patients on arm 1 had significantly (P < .05) more abdominal cramps, fatigue, transient hearing loss, febrile neutropenia, hypotension, myalgias, and skin rash and were removed from treatment more often as a result of toxicity than patients in arm 2 (26% v 13%, respectively; P = .003). More than 40% of patients did not have the tirapazamine dose escalated, primarily because of toxicity. The trial was closed early after an interim analysis demonstrated that the projected 37.5% improvement in survival (8 v 11 months median survival) in arm 1 was unachievable (P = .003). Conclusion: The addition of tirapazamine to paclitaxel and carboplatin does not result in improved survival in advanced NSCLC compared with paclitaxel and carboplatin alone but substantially increases toxicity.
ASJC Scopus subject areas
- Cancer Research