Phase III trial of ifosfamide with or without paclitaxel in advanced uterine carcinosarcoma: A gynecologic oncology group study

Purpose: To determine if paclitaxel added to ifosfamide as first-line treatment for advanced uterine carcinosarcoma (CS) improves overall survival (OS), progression-free survival (PFS), response, and toxicity. Patients and Methods: Eligible patients had measurable stage III or IV, persistent, or recurrent uterine CS. Random assignment to treatment was between ifosfamide 2.0 g/m² intravenously (IV) daily for 3 days (arm 1) or ifosfamide 1.6 g/m² IV daily for 3 days plus paclitaxel 135 mg/m² by 3-hour infusion day 1 (arm 2). Mesna was administered similarly (both arms); filgrastim began on day 4 (arm 2). Cycles were repeated every 21 days up to eight cycles. Results: Of 214 patients enrolled, 179 were eligible (arm 1, 91 patients; arm 2, 88 patients). Arm 2 patients experienced more frequent and severe sensory neuropathy (grade 1 to 4; 8% v 30%). The crude response rate was 29% (arm 1) and 45% (arm 2). The odds of response stratified by performance status were 2.21 greater in arm 2 (P = .017). Median PFS and OS, respectively, for arm 1 compared with arm 2 were 3.6 v 5.8 months and 8.4 v 13.5 months, respectively. There was a 31% decrease in the hazard of death (hazard ratio [HR], 0.69; 95% CI, 0.49 to 0.97; P = .03) and a 29% decrease in the hazard of progression (HR, 0.71; 95% CI, 0.51 to 0.97; P = .03) relative to arm 1 when stratifying by performance status. Conclusion: OS was significantly improved in arm 2, and toxicities were as expected and manageable. However, the need for active new agents persists, given that OS remains relatively poor in this disease.