A Two-part Phase IIb Trial of Vigil (Bi-shRNAfurin and GMCSF Augmented Autologous Tumor Cell Immunotherapy) in Ewing's Sarcoma

Part 1 Methodology:

This is a multicenter, 1:1 randomized Phase IIb study of intradermal autologous Vigil immunotherapy (1.0 x 10e7 cells/injection; minimum of 4 to a maximum of 12 administrations) versus gemcitabine / docetaxel in patients with metastatic Ewing's sarcoma Family of Tumors (ESFT) refractory or intolerant to at least 2 prior lines of chemotherapy. Patients undergoing a standard surgical procedure (e.g., tumor biopsy or palliative resection) may have tumor tissue harvested for manufacture of investigational product. Patients meeting eligibility criteria including manufacture of a minimum of 4 immunotherapy doses will be randomized to receive either (1) intradermal Vigil every 28 days for 4-12 administrations, or (2) gemcitabine 675 mg/m2 IV at 10 mg/m2/min D1 and D8 and docetaxel 75 mg/m2 IV D8 every 21 days. The primary trial objective is to determine the overall survival of patients treated with Vigil versus gemcitabine/docetaxel. Randomization may occur as early as vaccine is released (typically 3 - 4 weeks following tumor procurement) but no later than 8 weeks following tumor procurement. Randomization of patients will be stratified by Karnofsky Performance Status (KPS) ≥ 80% vs < 80%.

Patients will be managed in an outpatient setting. Hematologic function, liver enzymes, renal function and electrolytes will be monitored monthly. Blood for immune function analyses including IFNγ-ELISPOT analysis of cytotoxic T cell response to autologous tumor antigens will be collected at tissue procurement, baseline, and prior to product administration at Cycles 2, 4, end of treatment, and every 6 months thereafter.

Part 2 Methodology:

Based on the limited accrual to Part 1 of this study, Gradalis is opening Part 2 of this clinical protocol to assess the safety of Vigil immunotherapy in combination with irinotecan and temozolomide. Part 2 will be conducted at the same centers as Part 1, studying intradermal autologous Vigil cancer vaccine (1.0 x 10e7 cells/injection; minimum of 4 to a maximum of 12 administrations) in patients with metastatic Ewing's sarcoma Family of Tumors (ESFT) refractory or intolerant to at least 1 prior line of chemotherapy. Patients undergoing a standard surgical procedure (e.g., tumor biopsy or palliative resection) may have tumor tissue harvested for manufacture of investigational product. Patients meeting eligibility criteria including manufacture of a minimum of 4 immunotherapy doses of Vigil will be registered to receive: (i) oral temozolomide 100 mg/m2 daily (Days 1 - 5, total dose 500 mg/m2/cycle), (ii) irinotecan 50 mg/m2 daily (Days 1 - 5, total dose 250mg/m2/cycle), orally or irinotecan 20mg/m2 daily (Days 1 - 5, total dose 100mg/m2/cycle ), intravenously (iii) peg-filgrastim 100μg/kg (Day 6) subcutaneously (optional and may be administered at home), and (iv) Vigil 1.0 x 107 cells/injection, intradermally on Day 15 and every 3 weeks thereafter. One cycle = 21 days. Registration onto Part 2 may occur as early as one week but no later than 8 weeks following tumor procurement. Vigil is typically released approximately 3 weeks after the completion of the two-day manufacturing process.

Patients will be managed in an outpatient setting. Hematologic function, liver enzymes, renal function and electrolytes will be monitored. Blood for immune function analyses including IFNγ-ELISPOT analysis of cytotoxic T cell response to autologous tumor antigens will be collected at tissue procurement, post-procurement screening and prior to Day 15 Vigil administration at Cycles 2, 4, end of treatment, and every 6 months thereafter. Blood for ctDNA analysis will be collected prior to chemotherapy administration at baseline, Cycle 2 - Week 1 Day 1, Cycle 4 - Week 1 Day 1, and EOT.

Tissue Procurement Inclusion Criteria:

Patients will be eligible for tissue procurement for the Vigil manufacturing process, if they meet all of the following criteria:

• Histologically confirmed Ewing's Sarcoma Family of Tumors (ESFT)
• Age ≥2 years
• Estimated survival ≥ 6 months
• Evidence of EWS translocation by FISH or RT-PCR or Next Generation Sequencing (NGS) Metastatic disease
• Refractory or intolerant to ≥ 2 lines of systemic chemotherapy (Part 1) or Refractory or intolerant to at least 1 line of systemic chemotherapy (Part 2)
• Planned standard of care surgical procedure (e.g., tumor biopsy or palliative resection or thoracentesis) and expected availability of a cumulative mass of ~10-30 grams tissue ("golf-ball" size) or pleural fluid estimated volume ≥ 500mL (must be primary tap) for immunotherapy manufacture
• Tumor intended for immunotherapy manufacture is not embedded in bone and does not contain luminal tissue (e.g., bowel, ureter, bile duct)
• Ability to understand and the willingness to sign a written informed consent document for tissue harvest

Tissue Procurement Exclusion Criteria:

Patients meeting any of the following criteria are not eligible for tissue procurement for the Vigil manufacturing:

• Medical condition requiring any form of chronic systemic immunosuppressive therapy (steroid or other) except physiologic replacement doses of hydrocortisone or equivalent (no more than 30 mg hydrocortisone or 10 mg prednisone equivalent daily) for < 30 days duration
• 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
• Brain metastases unless treated with curative intent (gamma knife or surgical resection) and without evidence of progression for ≥ 2 months
• Any documented history of autoimmune disease with exception of Type 1 diabetes on stable insulin regimen, hypothyroidism on stable dose of replacement thyroid medication, vitiligo, or asthma not requiring systemic steroids
• Known history of allergies or sensitivities to gentamicin
• Known hypersensitivity reactions to docetaxel or to other drugs formulated with polysorbate 80 that would preclude treatment with docetaxel (Part 1 only)
• 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 patient's participation for the full duration of the study, or is not in the best interest of the patient to participate, in the opinion of the treating Investigator.
• Known HIV or chronic Hepatitis B or C infection

Study Enrollment Inclusion Criteria:

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

• Successful manufacturing of at least 4 vials of Vigil
• Karnofsky performance status (KPS) ≥60% (Part 1) or KPS ≥80% (Part 2)
• Estimated survival ≥ 4 months (Part 1) or estimated survival of ≥6 months (Part 2)
• Normal organ and marrow function as defined below:

• Absolute granulocyte count ≥1,500/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
• 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.
• 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.
• Ability to understand and the willingness to sign a written informed protocol specific consent

Study Enrollment Exclusion Criteria:

Measureable disease is not a requirement for enrollment onto the trial.

In addition to the procurement exclusion criteria, patients will NOT be eligible for study registration and randomization if meeting any of the following criteria:

• Any anti-neoplastic therapy between tissue procurement for Vigil manufacture and start of study therapy
• Live vaccine used for the prevention of infectious disease administered < 30 days prior to the start of study therapy
• Post-surgery complication that in the opinion of the treating investigator would interfere with the patient's study participation or make it not in the best interest of the patient to participate