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

Inclusion Criteria:

1. Patients must be ≥ 12 months and ≤ 50 years of age at the time of study enrollment.

2. Patients with histologically confirmed solid tumors with an estimated poor long termsurvival.

3. Performance Level: Karnofsky ≥ 50% for patients > 16 years of age and Lansky ≥ 60for patients ≤16 years of age.

4. Patients must be post RIC haploidentical BMT.

5. Patients must have fully recovered from the acute toxic effects of prior BMT.

6. Concomitant radiation therapy can be administered in the setting of this trial.

7. Subjects must consent to allow for a baseline tumor biopsy. If a biopsy is notfeasible, then archival tumor material must be made available. Tumor biopsies to betaken (if a subject's tumor is thought to be reasonably safe and easy to biopsy) atbaseline (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 orimaging studies in the case of no identifiable masses at cycle 2. Additionaloptional biopsies may be obtained later in the course of study treatment. Theproposed investigation is considered a non-significant risk (NSR). A significantrisk procedure is generally considered to be one for which the procedure-associatedabsolute risk of mortality or major morbidity, in the patient's clinical setting andat the institution completing the procedure, is 2% or higher. Diagnostic TissueSamples Tissue, fluid, or blood may be collected from standard of care proceduresused to treat or diagnose immune related toxicities/GVHD.

8. Organ Function Requirements: I. Adequate Hematologic Parameters:

9. For patients with solid tumors without known bone marrow involvement:

• Peripheral absolute neutrophil count (ANC) ≥ 500/mm3
• Platelet count ≥ 50,000/mm3

2. Patients with known bone marrow metastatic disease will be eligible for studywithout the above criteria. They may receive transfusions provided they are notknown to be refractory to red cell or platelet transfusions. These patientswill not be evaluable for hematologic toxicity. II. Adequate Renal Function Defined as:

3. Creatinine clearance or radioisotope Glomerular filtration rate (GFR) ≥ 70ml/min/1.73 m2 or

4. A serum creatinine based on age/gender as follows:

• Age 1 to <2 years, Male: 0.6 and Female: 0.6
• Age 2 to <6 years, Male: 0.8 and Female: 0.8
• Age 6 to <10 years, Male: 1 and Female:1
• Age 10 to <13 years, Male: 1.2 and Female 1.2
• Age 13 to <16 years, Male: 1.5 and Female 1.4
• Age ≥ 16 years, Male: 1.7 and Female 1.4 III. Adequate Liver Function Defined as:

1. Bilirubin (sum of conjugated + unconjugated) ≤1.5 x upper limit of normal (ULN)for age

2. Serum glutamic pyruvic transaminase (SGPT) (ALT) ≤110 U/L. For the purpose ofthis study, the ULN for SGPT is 45 U/L.

3. Patients must have been registered on protocol J12106 "A Phase II Trial of ReducedIntensity Conditioning and HLA-matched or Partially HLA-mismatched (HLA-haploidentical) Related Donor Bone Marrow Transplant for High-risk SolidTumors" before enrolling on this study.Patient may be screened prior to Day +120 butfirst dose of study drug must be given on or after Day +120.

Exclusion Criteria:

1. GVHD: any history of Stage 4 skin GVHD or Stage 3 gut/liver GVHD (a.k.a. overallGrade III/IV GVHD) or any severe chronic GVHD. Any person with ≤ Grade II GVHD mustbe off systemic immunosuppressive therapy for at least 2 weeks prior to receivingNivolumab therapy.

2. Inhaled or topical steroids and adrenal replacement steroid doses are permitted inthe absence of active auto- or allo-immune disease

3. BMT-related toxicities: patients who developed idiopathic pneumonia syndrome (IPS)or veno-occlusive hepatic disease (VOD) must be off systemic immunosuppressionand/or defibrotide for at least 14 days to be eligible.

4. Infection: Patients who have an uncontrolled infection.

5. Patients who in the opinion of the investigator may not be able to comply with thesafety monitoring requirements of the study are not eligible.

6. Has active, known or suspected autoimmune disease. Subjects with vitiligo, type Idiabetes mellitus, residual hypothyroidism due to autoimmune thyroiditis onlyrequiring hormone replacement, or conditions not expected to recur in the absence ofan external trigger are permitted to enroll.

7. Allergies and Adverse Drug Reaction

8. History of allergy to study drug components.

9. History of severe hypersensitivity reaction to any monoclonal antibody.

10. Pregnancy or Breast Feeding: Women of childbearing potential (WOCBP) must agree tofollow instructions for method(s) of contraception for the duration of studytreatment with nivolumab and 5 months after the last dose of study treatment {i.e., 30 days (duration of ovulatory cycle) plus the time required for the investigationaldrug to undergo approximately five half-lives. Males who are sexually active withWOCBP must agree to follow instructions for method(s) of contraception for theduration of study treatment with nivolumab and 7 months after the last dose of studytreatment {i.e., 90 days (duration of sperm turnover) plus the time required for theinvestigational drug to undergo approximately five half-lives.