A phase II evaluation of trabectedin in the treatment of advanced, persistent, or recurrent uterine leiomyosarcoma: A gynecologic oncology group study

ObjectiveTo estimate activity and safety of trabectedin 1.5 mg/m2 IV over 24 hours every 3 weeks (1 cycle) in uterine leiomyosarcoma.MethodsPatients with chemotherapy naive, advanced, persistent or recurrent uterine leiomyosarcoma, acceptable organ function and PS ≤ 2 were eligible. A two-stage design was utilized. Three responses were required in the first stage to initiate the second stage; the target sample size was 40 for the combined stages. If the true response rate was 10%, the study design provided a 95% chance of correctly classifying the treatment as “inactive.” Conversely, if the true response rate was 30%, then the average probability of correctly classifying the treatment as active would be 90%.ResultsTwenty patients were eligible and evaluable. The median number of cycles was 10 (123 total cycles, range 2-29). The number of patients with partial responses was 2 (10%; 95% confidence interval of 1.2%-31.7%). Response durations were 3.3 and 5.7 months. Ten patients had stable disease (50%). The median progression-free survival (PFS) and overall survival were 5.8 months and greater than 26.1 months (median not reached), respectively. Observed grade 3/4 toxicity included: neutropenia 16/20 (1 infection); thrombocytopenia 3/20; metabolic 3/20; anemia, gastrointestinal and vascular 1/20 each. There were no treatment related deaths nor cases of liver failure.ConclusionsAlthough a second stage of accrual was not indicated based on the overall response rate, the drug was well tolerated.

► Trabectedin 1.5 mg/m2 IV over 24 hours every 3 weeks did not generate enough objective responses among women with chemotherapy naive, advanced, persistent or recurrent uterine leiomyosarcoma to justify a second stage of accrual. ► However, 50% of treated subjects remained progression-free for at least 6 months.