Pilot Study of Recurrent Ewing's Sarcoma Management with Vigil/Temozolomide/Irinotecan and Assessment of Circulating Tumor (ct) DNA.

PURPOSE: Treatment options for recurrent or refractory Ewing's sarcoma (ES) are limited. Vigil is a novel autologous tumor cell therapy expressing bi-shRNA furin/GMCSF plasmid, which previously demonstrated monotherapy activity in advanced ES. Herein we report safety and evidence of benefit to Vigil for ES as potential treatment. PATIENTS AND METHODS: In this pilot trial, eligible patients with recurrent or refractory ES who failed initial standard-of-care therapy received treatment with temozolomide (TEM) 100 mg/m2/day oral and irinotecan (IRI) 50 mg/m2/day oral, Days 1 to 5, in combination with Vigil (1 × 106-107 cells/mL/day intradermal, Day 15), every 21 days (Vigil/TEM/IRI). Objective response rate (ORR) by RECIST v1.1, progression-free survival (PFS), and overall survival (OS) were assessed. Circulating tumor (ct) DNA analysis was done by patient-specific droplet digital PCR on baseline and serially collected on-treatment samples. RESULTS: Eight of 10 enrolled patients were evaluable for safety and efficacy (mean age 24.6; 12.6-46.1 years old); 2 did not receive Vigil. Seven of 8 patients previously received TEM/IRI. No Vigil-related adverse events were reported. Common ≥Grade 3 chemotherapy-related toxicity included neutropenia (50%) and thrombocytopenia (38%). We observed two partial response patients by RECIST; both showed histologic complete response without additional cancer therapy. Median PFS was 8.2 months (95% confidence interval, 4.3-NA). Five patients showed stable disease or better for ≥6 months. Patient-specific EWS/FLI1 ctDNA was detectable in all 8 evaluable patients at baseline. Changes in ctDNA levels corresponded to changes in disease burden. CONCLUSIONS: Results demonstrated safety of combination Vigil/TEM/IRI.

Proof of principle study of sequential combination atezolizumab and Vigil in relapsed ovarian cancer.

Vigil® is a personalized vaccine that enhances tumor neoantigen expression. We investigated for the first time safety and efficacy of Vigil in combination with atezolizumab in relapsed ovarian cancer (OC) patients. This is a randomized, Phase 1 study of Vigil, an autologous tumor tissue transfected vaccine encoding for GMCSF and bi-shRNA-furin thereby creating enhanced immune activation and TGFß expression control. Part 1 is a safety assessment of Vigil (1 × 10e7 cells/mL/21 days) plus atezolizumab (1200 mg/21 days). Part 2 is a randomized study of Vigil first (Vigil-1st) or atezolizumab first (Atezo-1st) for two cycles followed by the combination of both agents. The primary endpoint of the study was the determination of safety. Twenty-four patients were enrolled in the study; three patients to Part 1 and 21 to Part 2. Patients in Part 1 completed combination therapy without dose-limiting toxicity justifying expansion to Part 2. Twenty-one patients were randomized (1:1) to Part 2 to Vigil-1st (n = 11) or Atezo-1st (n = 10). Grade 3/4 treatment-related adverse events of Atezo-1st vs. Vigil-1st were 17.2% vs. 5.1%. Median overall survival (OS) was not reached (NR) (Vigil-1st) vs. 10.8 months (Atezo-1st) (hazard ratio [HR] 0.33). The exploratory subset analysis of BRCAwt suggested improved OS benefit [NR in Vigil-1st vs. 5.2 months in Atezo-1st, HR 0.16, p 0.027]. The Vigil-1st combination therapy with atezolizumab was safe and results in support continued investigation in BRCAwt patients.

Corrigendum to "Long-term follow-up of Phase 2A trial results involving advanced ovarian cancer patients treated with Vigil® in frontline maintenance" [Gynecol. Oncol. Rep. 34 (2020) 100648].

[This corrects the article DOI: 10.1016/j.gore.2020.100648.].

Case Report: Immune-mediated Complete Response in a Patient With Recurrent Advanced Ewing Sarcoma (EWS) After Vigil Immunotherapy.

Ewing sarcoma is a highly resistant disease with a <10% chance of survival at 5 years after failure of frontline chemotherapy. This is a case report of an Ewing sarcoma patient with metastatic disease recurrence <2 years after standard chemotherapy/radiation who achieved a durable and sustained complete response after 2 series of treatments with Vigil (GMCSF/bi-shRNA furin DNA autologous tumor immunotherapy) serially manufactured from first and second recurrences with ELISPOT assay correlation. Results support justification of further testing of Vigil with ELISPOT assay as a biomarker to assess level of immune response and correlation with disease control.