Trial of Nab-paclitaxel in Patients With Desmoid Tumors and Multiply Relapsed/Refractory Desmoplastic Small Round Cell Tumors and Ewing Sarcoma

A two-cohort, fase II, open-label, non-randomized, multicenter clinical trial. 14 sites in Spain. Cohort 1: Subjects with desmoid tumor (DT) Cohort 2: Subjects with desmoplastic small round cell tumor or Ewing sarcoma (DSRCT and ES) Nab-paclitaxel (ABRAXANE) will be administered as follows: Age ≥ 21 and ≤ 80 years: 125 mg/m2 days 1, 8 and 15 in cycles of 28 days Age ≥ 6 months and ≤ 20 years: 240 mg/m2 days 1, 8 and 15 in cycles of 28 days Subjects in the DT cohort will receive a maximum of three cycles. Subjects in the DSRCT and ES cohort will receive unlimited cycles until disease progression, the subject begins a new anticancer treatment, withdrawal of parent/guardian/subject consent/assent, parent/guardian/subject refusal, physician decision, toxicity that cannot be managed by dose delay or dose reduction alone or the study ends for any reason. The main goal is to determine the objective response rate (ORR), using RECIST 1.1 criteria and to determine the clinical benefit rate (CBR), defined as CR+PR+SD for 3 months with improvement of pain with at least minimally important difference (MID) of 2 in subjects with desmoid tumors (DT cohort) and to determine the objective response rate (ORR) in subjects with desmoplastic small round cell tumor and Ewing sarcoma, using RECIST 1.1 criteria (DSRCT and ES cohort)