Trabectedin (T) In Advanced, Pretreated Synovial Sarcomas (Ss): A Retrospective Analysis Of 39 Patients (Pts) From Three European Institutions.

10030 Background: T is effective in advanced soft tissue sarcomas, with special regard to liposarcoma and leiomyosarcoma. Mechanisms of action may be multifold: induction of DNA damage, involving specific and peculiar DNA repair pathways, and transcriptional interference. The latter mechanism may be more significant in myxoid liposarcomas. Other translocation-related sarcomas may be sensitive to T. SS is a translocation-related sarcoma. We report on a series of 39 pts with advanced SS who were treated with T in three European sarcoma centres within compassionate-use programs. Methods: The datasets of Istituto Nazionale Tumori, Milano, Italy; Centre Leon Berard, Lyon, and Institut Gustave Roussy, Villejuif, France, were retrospectively reviewed from 2000 to 2009. Overall, 21/39 pts were female, and age ranged from 18 to 67 years. Sites of primary lesions were extremities = 23, mediastinum = 6, trunk = 5, pelvis = 4, head and neck = 1. At the time of treatment, all pts presented with metastatic disease, and were pre-treated with a median of 3 chemotherapy lines (range: 2-7). Results: 186 courses were delivered (median: 3). All pts were evaluable for response. Seven pts had a PR, for an overall response rate (RR) of 18%. In addition, 2 MR, and 11 SD were observed. Progression-free survival at 6 months (PFR-6) was 23%. Median PFS was 29, 21, and 18 weeks, respectively, in pts who experienced PR, MR and SD. Conclusions: In this series of adult pts with advanced pre-treated SS, T induced a RR of 18% and a PFR-6 of 23%. This suggests that SS constitute a sarcoma subgroup with distinct sensitivity to T. Author Disclosure Employment or Leadership Position Consultant or Advisory Role Stock Ownership Honoraria Research Funding Expert Testimony Other Remuneration PharmaMar PharmaMar PharmaMar PharmaMar PharmaMar PharmaMar