Rechallenge with trabectedin in patients with locally advanced or metastatic soft tissue sarcoma following drug holiday: The experience of the French Sarcoma Group (FSG).

10062 Background: Trabectedin (T) is a marine-derived alkaloid used to treat advanced soft tissue sarcomas (STS) after ifosfamide and/or anthracyclins failure. Since then, the FSG evaluated the clinical benefit in re-administrating T after an initial hold, either medically indicated or upon patient’s request. Methods: Following an online request, clinical and histopathological data were collected from six centers of the FSG who declared to have rechallenged patients. Baseline data were collected and analyze will be used. Results: From 1999 to 2011, 49 pts with T drug holiday have been identified (26 male/ 23 female), with a median age of 50 y [23-75]. Most frequent histotypes were: myxoid liposarcoma (18, 36.7%), leiomyosarcomas (13, 26.5 %) and well-differentiated/dedifferentiated liposarcoma (9, 18%). WHO grade were 1 in 14 (29%), 2 in 19 (39%) and 3 in 5 (10%) pts respectively. Patients who had a maximum of 2, 3 or 4 therapeutic sequences (TS) with T (drug-holiday and rechallenge) were 41/49 ,7/49 and ...