Trial in Patients With Metastatic or Locally Advanced Leiomyosarcoma

The management of patients with leiomyosarcomas determines many difficulties. Despite patients with metastatic disease at diagnosis or who recur after initial treatment have a dismal prognosis and, except for a subset of selected patients with completely resectable disease, the median survival is less than two years. At the advanced-disease stage, the main aim of treatment is to improve patient's quality of life, possibly survival, with the best compromise between toxicity and symptoms. Trabectedin (T) is a marine-derived cytotoxic approved by European MEdicine Agency (EMEA) and FDA. It is indicated for the treatment of patients with advanced soft tissue sarcoma, after failure of anthracyclines-based chemotherapy or who are unsuitable to receive these agents. Among Soft Tissue Sarcoma (STS), activity has been mainly detected in synovial sarcoma, liposarcoma and leiomyosarcoma. Although the response rate did not exceed 10%, T was demonstrated to provide disease control, with progression arrest rates exceeding 50% and progression-free survival rates exceeding 20% at 6 months. So far no phase II or III studies have been addressed to test the activity of T in leiomyosarcoma specifically (without differentiation between site of primary localization) in comparison with Gemcitabine. This study is aimed at evaluating the activity of Trabectedin (arm A) in advanced leiomyosarcomas, having Gemcitabine (arm B) as the comparator. In parallel an optional translational study will be performed to identify factors predictive of the activity of Trabectedin or Gemcitabine in this specific histotype. In addition to the randomized cohort, the study has also an observational prospective cohort which include patients who will refuse the randomization or for whom the investigator will not judge the randomization as an appropriate option. In order to allow the participation of sites only to the prospective-observational (non randomized) cohort, it was introduced the possibility to participate to the study and receive the ethical approval only to the Observational Prospective Cohort In parallel an optional translational study will be performed, in both cohorts, to identify factors predictive of the activity of Trabectedin or Gemcitabine in this specific histotype.