Rechallenge with trabectedin in patients with responding myxoid liposarcoma

10575 Background: To determine the efficacy of rechallenge with trabectedin (T) in patients with myxoid liposarcoma who were responding to T at the time of discontinuation but subsequently developed progressive disease. Methods: Since September 2002, 32 patients with recurrent or advanced myxoid liposarcoma received T at our institution within an expanded access program. We report herein 8 patients who received T for a median of 10 cycles (range 5–15) prior to discontinuation. We used RECIST criteria to classify patient response to therapy. During the initial administration of T, a CR had been observed in 2 patients, a PR in 3 patients, SD in 2 patients, and one had had tumor shrinkage but did not meet RECIST definition of PR. The median PFS was 24 months from treatment start, and 14 months (range 9–27) from treatment-end. In 6 of the 8 patients, the treatment had been discontinued in the absence of any evidence of disease: 4 patients had undergone complete surgical resection (R0) of residual disease and ...