Pbi-shRNA™ EWS/FLI1 Type 1 LPX in Subjects With Advanced Ewing's Sarcoma

Subjects will be eligible for registration if they meet all of the following inclusion criteria:

Inclusion Criteria:

1. Histologically confirmed Ewing's Sarcoma Family of Tumors (ESFT).
2. Age ≥8 years.
3. Evidence of EWS translocation fusion by FISH or RT-PCR or NGS.
4. Evidence of Type 1 fusion by molecular diagnostics.
5. Refractory or intolerant to standard of care. Subjects must have failed surgery (if resectable), radiation (if no function-preserving surgical approach at primary site, unresectable primary following induction chemotherapy, residual microscopic or gross disease after surgery or inadequate margins), and the following chemotherapy agents: doxorubicin, vincristine, cyclophosphamide, ifosfamide, etoposide.
6. ECOG performance status (PS) = 0-2, or Karnofsky PS ≥60% or Lansky PS ≥60%.
7. Normal organ and marrow function as defined below:

   Absolute granulocyte count ≥1,000/mm3 Absolute lymphocyte count ≥400/mm3 Platelets ≥100,000/mm3 Total bilirubin ≤ institutional upper limit of normal AST(SGOT)/ALT(SGPT) ≤2x institutional upper limit of normal Creatinine \<1.5 mg/dL
8. Normal pulmonary function as defined as FEV1/FVC greater than 70% in adults or greater than 80% in individuals between 8 and 18 years of age.
9. Subject has recovered to CTCAE Grade 1 or better from all adverse events associated with prior therapy or surgery. Pre-existing motor or sensory neurologic pathology or symptoms must be recovered to CTCAE Grade 2 or better.
10. If female of childbearing potential, has a negative urine or serum pregnancy test. If the urine test is positive or cannot be confirmed as negative, a negative serum test will be required for study entry.
11. Ability to understand and the willingness to sign a written informed protocol specific consent. Pediatric patients must sign an assent with a parent or legal guardian sign a written informed consent, per institutional guidelines.

Subjects will NOT be eligible for study registration and enrollment if meeting any of the following criteria:

Exclusion Criteria:

1. Anti-cancer chemotherapy, biologic therapy or immunotherapy within 3 weeks or radiation therapy within 2 weeks of first infusion.
2. Known history of other malignancy unless having undergone curative intent therapy without evidence of that disease for ≥ 3 years except cutaneous squamous cell and basal cell skin cancer, superficial bladder cancer, in situ cervical cancer or other in situ cancers are allowed if definitively resected.
3. Patients with PET avid disease only will be excluded.
4. Brain metastases unless treated with curative intent (gamma knife or surgical resection) and without evidence of progression for ≥ 2 months.
5. History of or current evidence of thrombosis.
6. History of or current evidence of any condition (including medical, psychiatric or substance abuse disorder), therapy, or laboratory abnormality that might confound the results of the study, interfere with the subject's participation for the full duration of the study, or is not in the best interest of the subject to participate, in the opinion of the Investigator.
7. Known HIV or chronic Hepatitis B or C infection.
8. Have signs and symptoms consistent with an active infection.
9. Live vaccination for the prevention of infectious disease administered \<30 days prior to the start of study therapy or inactivated vaccination \<14 days prior to the start of study therapy.