This is an Italian, multicenter, randomized, open-label , two arm, study, to determine the best time to secondary resistance between responding patients who discontinue treatment and resumed Trabectedin at the time of progression versus patients who continued treatment until progression. The aim is to evaluate the best clinical practice for responding patients as Trabectedin has an acceptable safety profile with no evidence of cumulative toxicity.~After signing informed consent and being assessed for eligibility criteria , eligible patients will start the trabectedin treatment.~All the patients who will complete 6 cycles of treatment without disease progression will be be randomized to continue Trabectedin versus treatment interruption followed by re-challenge at progression. Patients randomized to discontinue treatment will be candidate to other 6 cycles of treatment and if they do not progress, to another interruption. The treatment will be resumed again at progression for other 6 cycles and this scheme of treatment will be proposed until progression under Trabectedin.~The study will be conducted in Italy in approximately 12 centers, in order to recruit 330 evaluable patients over a 4 year period. The follow-up will last approximately 3 years.
Two arm, randomized, open-label study, to determine the best time to secondary resistance between responding patients who discontinue treatment and resumed Trabectedin at the time of progression versus patients who continued treatment until progression. T