Trial of Nivolumab Following Partially Human Leukocyte Antigen (HLA) Mismatched BMT in Children & Adults With Sarcoma

Inclusion criteria

• . Patients must be ≥ 12 months and ≤ 50 years of age at the time of study enrollment.
• . Patients with histologically confirmed solid tumors with an estimated poor long term survival.
• . Performance Level: Karnofsky ≥ 50% for patients \> 16 years of age and Lansky ≥ 60 for patients ≤16 years of age.
• . Patients must be post RIC haploidentical BMT.
• . Patients must have fully recovered from the acute toxic effects of prior BMT.
• . Concomitant radiation therapy can be administered in the setting of this trial.
• . Subjects must consent to allow for a baseline tumor biopsy. If a biopsy is not feasible, then archival tumor material must be made available. Tumor biopsies to be taken (if a subject's tumor is thought to be reasonably safe and easy to biopsy) at baseline (any time prior to the first dose after eligibility is met) and at Cycle 2 (4-6 cores per time point) or when lesions are visualized on physical examination or imaging studies in the case of no identifiable masses at cycle 2. Additional optional biopsies may be obtained later in the course of study treatment. The proposed investigation is considered a non-significant risk (NSR). A significant risk procedure is generally considered to be one for which the procedure-associated absolute risk of mortality or major morbidity, in the patient's clinical setting and at the institution completing the procedure, is 2% or higher. Diagnostic Tissue Samples Tissue, fluid, or blood may be collected from standard of care procedures used to treat or diagnose immune related toxicities/GVHD.