This is the first study to test the activity of trabectedin in uterine leiomyosarcoma (U-LMS). Patients were eligible after receipt of 2 or more lines of chemotherapy, either in the adjuvant setting or as first-line therapy for advanced disease. Patients with U-LMS who had not already received gemcitabine + docetaxel were randomized to either trabectedin 1.3 mg/m2 or gemcitabine + docetaxel: gemcitabine 900 mg/m2 on days 1 and 8 and docetaxel 75 mg/m2 on day 8. At progression, patients who were randomized to gemcitabine + docetaxel could receive trabectedin. The primary end point was the rate of 6-month progression-free survival (PFS-6).
Between April 2010 and January 2016, 168 patients were enrolled from 26 sites: 126 patients received trabectedin and 42 patients received gemcitabine + docetaxel. Based on data from the first 113 patients who received trabectedin, the PFS-6 rate was 33% and the PFS-12 rate was 20%. No toxic deaths occurred.
Researchers concluded that trabectedin is active in patients with U-LMS who were pretreated with conventional chemotherapy. They note that its efficacy appears to remain unchanged across patients who received 1 to 3 previous lines of chemotherapy.