ABSTRACT
We describe in this review the historical evidence leading up to the concept and design of Vigil and subsequent clinical applications including safety and efficacy in a randomized, controlled Phase IIB trial. Vigil (gemogenovatucel-T) is a unique triple function targeted immunotherapy that demonstrates preclinical and clinical systemic anticancer activity. Construction of Vigil involves harvest of autologous malignant tissue for neoantigen targeting (ideally containing clonal neoantigens) followed by a two-day process involving transfection with a plasmid to provide a permissive 'training environment' for the patient's immune system. Transfected plasmid components contain an expressive human GMCSF DNA segment to enhance anticancer immune functional response and a second component expressing bi-shRNAfurin which reduces TGFß isomers (TGFß1 and TGFß2) thereby reducing cancer inhibition of the targeted immune response. Results generated to date justify advancement to confirmatory clinical trials supporting product regulatory approval.
Vigil is an anticancer treatment that employs three methods of enhancing the body's immune system to identify and kill cancer cells. The construction of Vigil involves cancer cells from the same person being treated (personalized therapy) in combination with added anticancer genetic signals to enhance the number and function anti-anticancer immune cells and to guide the immune cells to the cancer and not to normal organs of the body. In this manner, an army of immune cells are created that can move to attacking the cancer using blood vessels to get to the cancer anywhere it tries to grow in the body. One study (Phase I) performed with this product to determine safety and dose range demonstrated an optimal dose and schedule. Another study (Phase IIA) showed initial clinical benefit. A third more complex study (Phase IIB) in patients treated with Vigil compared with standard of care without Vigil demonstrated the ability to prolong the patients life and time without their cancer getting worse without any significant side effects associated with the treatment in a unique subset of ovarian cancer patients, those with the ability to repair their DNA. Based on the composite of these results, Vigil is an attractive targeted immunotherapy justified for late-stage clinical testing.
ABSTRACT
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.
Subject(s)
Circulating Tumor DNA , Sarcoma, Ewing , Humans , Young Adult , Adult , Child , Adolescent , Middle Aged , Irinotecan/adverse effects , Temozolomide/adverse effects , Sarcoma, Ewing/drug therapy , Sarcoma, Ewing/genetics , Sarcoma, Ewing/pathology , Pilot Projects , Circulating Tumor DNA/genetics , Neoplasm Recurrence, Local/drug therapy , Neoplasm Recurrence, Local/genetics , Modafinil/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/adverse effectsABSTRACT
BACKGROUND: Ewing sarcoma breakpoint region 1 gene (EWSR1) rearrangements are largely associated with the Ewing sarcoma family of tumors. OBSERVATIONS: We report the first case of infantile, mixed phenotype acute leukemia, B/myeloid (bilineal and biphenotypic [B-lymphoid and B-lymphoid/myeloid]), with a t(2;22)(q35;q12). The EWSR1-fifth Ewing variant gene fusion and nonsense mutation in STAG2 were detected by next-generation sequencing and markedly high expression of fifth Ewing sarcoma variant mRNA detected by quantitative reverse transcription polymerase chain reaction. The patient was treated with a combined myeloid/lymphoid leukemia regimen followed by allogeneic stem cell transplant and was in complete remission at 3.8-year follow-up. CONCLUSIONS: Our case study underscores the importance of a comprehensive evaluation of acute leukemia and provides insights into the phenotype of EWSR1 rearranged neoplasms in the context of partner genes and cell type.
Subject(s)
DNA-Binding Proteins/genetics , Leukemia, Biphenotypic, Acute/genetics , Leukemia, Myeloid, Acute/genetics , Oncogene Proteins, Fusion/genetics , RNA-Binding Protein EWS/genetics , Transcription Factors/genetics , Cell Cycle Proteins/genetics , Codon, Nonsense , Female , Humans , Infant , Translocation, GeneticABSTRACT
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.
Subject(s)
Benzhydryl Compounds/administration & dosage , Cancer Vaccines/administration & dosage , Immunotherapy/methods , Sarcoma, Ewing/therapy , Adolescent , Benzhydryl Compounds/therapeutic use , Cancer Vaccines/therapeutic use , Enzyme-Linked Immunospot Assay , Female , Granulocyte-Macrophage Colony-Stimulating Factor/therapeutic use , Humans , Modafinil , RNA, Small Interfering/therapeutic use , Salvage Therapy/methods , Sarcoma, Ewing/diagnosis , Treatment OutcomeABSTRACT
The EWS/FLI1 fusion gene is well characterized as a driver of Ewing's sarcoma. Bi-shRNA EWS/FLI1 is a functional plasmid DNA construct that transcribes both siRNA and miRNA-like effectors each of which targets the identical type 1 translocation junction region of the EWS/FLI1 transcribed mRNA sequence. Previous preclinical and clinical studies confirm the safety of this RNA interference platform technology and consistently demonstrate designated mRNA and protein target knockdown at greater than 90% efficiency. We initiated development of pbi-shRNA EWS/FLI1 lipoplex (LPX) for the treatment of type 1 Ewing's sarcoma. Clinical-grade plasmid was manufactured and both sequence and activity verified. Target protein and RNA knockdown of 85-92% was demonstrated in vitro in type 1 human Ewing's sarcoma tumor cell lines with the optimal bi-shRNA EWS/FLI1 plasmid. This functional plasmid was placed in a clinically tested, liposomal (LP) delivery vehicle followed by in vivo verification of activity. Type 1 Ewing's sarcoma xenograft modeling confirmed dose related safety and tumor response to pbi-shRNA EWS/FLI1 LPX. Toxicology studies in mini-pigs with doses comparable to the demonstrated in vivo efficacy dose resulted in transient fever, occasional limited hypertension at low- and high-dose assessment and transient liver enzyme elevation at high dose. These results provide the justification to initiate clinical testing.
Subject(s)
Liposomes , Oncogene Proteins, Fusion/genetics , Proto-Oncogene Protein c-fli-1/genetics , RNA, Small Interfering/genetics , RNA-Binding Protein EWS/genetics , Sarcoma, Ewing/genetics , Animals , Binding Sites , Cell Line, Tumor , Cytokines/metabolism , Disease Models, Animal , Drug Evaluation, Preclinical , Female , Gene Knockdown Techniques , Gene Order , Genetic Therapy , Humans , Inflammation Mediators , Male , Oncogene Proteins, Fusion/administration & dosage , Oncogene Proteins, Fusion/chemistry , Plasmids/administration & dosage , Plasmids/genetics , Proto-Oncogene Protein c-fli-1/administration & dosage , Proto-Oncogene Protein c-fli-1/chemistry , RNA Interference , RNA, Small Interfering/administration & dosage , RNA, Small Interfering/chemistry , RNA-Binding Protein EWS/administration & dosage , RNA-Binding Protein EWS/chemistry , Sarcoma, Ewing/mortality , Sarcoma, Ewing/pathology , Sarcoma, Ewing/therapy , Targeted Gene Repair , Transfection , Tumor Burden , Xenograft Model Antitumor AssaysABSTRACT
Ewing's sarcoma is a devastating rare pediatric cancer of the bone. Intense chemotherapy temporarily controls disease in most patients at presentation but has limited effect in patients with progressive or recurrent disease. We previously described preliminary results of a novel immunotherapy, FANG (Vigil) vaccine, in which 12 advanced stage Ewing's patients were safely treated and went on to achieve a predicted immune response (IFNγ ELISPOT). We describe follow-up through year 3 of a prospective, nonrandomized study comparing an expanded group of Vigil-treated advanced disease Ewing's sarcoma patients (n = 16) with a contemporaneous group of Ewing's sarcoma patients (n = 14) not treated with Vigil. Long-term follow-up results show a survival benefit without evidence of significant toxicity (no ≥ grade 3) to Vigil when administered once monthly by intradermal injection (1 × 10e(6) cells/injection to 1 × 10e(7) cells/injection). Specifically, we report a 1-year actual survival of 73% for Vigil-treated patients compared to 23% in those not treated with Vigil. In addition, there was a 17.2-month difference in overall survival (OS; Kaplan-Meier) between the Vigil (median OS 731 days) and no Vigil patient groups (median OS 207 days). In conclusion, these results supply the rational for further testing of Vigil in advanced stage Ewing's sarcoma.
ABSTRACT
We report on 12 consecutive patients with advanced/metastatic Ewing's sarcoma who were treated as a separate cohort of a phase 1 trial of FANG autologous immunotherapy (1 × 10(6)-2.5 × 10(7) cells/intradermal injection each month for minimum 4 months). Safety and clinical response were monitored. Patient immune response to unmodified autologous tumor cells was assessed by gamma interferon-enzyme-linked immunospot (γIFN-ELISPOT) assay using peripheral blood mononuclear cells from baseline (pretreatment) and multiple postvaccination time points. None of the 12 patients (47 vaccinations) developed grade 2/3/4 drug-related toxicity. Median product release granulocyte-macrophage colony-stimulating factor expression was 1,941 pg/10(6) cells, and TGFß1and TGFß2 knockdown were 99 and 100%, respectively. Eight patients were assessed for ELISPOT response to autologous tumor cells at baseline and all (100%) were negative. In contrast, follow-up ELISPOT response at month 1 or month 4 (one patient) after FANG was positive in all eight patients. One patient achieved a partial tumor response (38% tumor reduction, RECIST 1.1). The Kaplan-Meier estimated survival of these 12 patients at 1 year was 75%. In this phase 1 study in patients with Ewing's sarcoma, FANG immunotherapy was well tolerated, elicited a tumor-specific systemic immune response in all patients, and was associated with favorable 1-year survival. Further clinical testing is indicated.
Subject(s)
Immunotherapy/methods , Sarcoma, Ewing/therapy , Adolescent , Adult , Female , Gene Expression Regulation , Granulocyte-Macrophage Colony-Stimulating Factor/genetics , Granulocyte-Macrophage Colony-Stimulating Factor/metabolism , Humans , Interferon-gamma/metabolism , Leukocytes, Mononuclear/metabolism , Male , Middle Aged , Neoplasm Metastasis/therapy , Pilot Projects , Transforming Growth Factor beta1/genetics , Transforming Growth Factor beta1/metabolism , Transforming Growth Factor beta2/genetics , Transforming Growth Factor beta2/metabolism , Treatment Outcome , Young AdultABSTRACT
Children with high-risk and recurrent neuroblastoma have poor survival rates, and novel therapies are needed. Many cancer cells have been found to preferentially employ the glycolytic pathway for energy generation, even in the presence of oxygen. 3-BrOP is a novel inhibitor of glycolysis, and has demonstrated efficacy against a wide range of tumor types. To determine whether human neuroblastoma cells are susceptible to glycolysis inhibition, we evaluated the role of 3-BrOP in neuroblastoma model systems. Neuroblastoma tumor cell lines demonstrated high rates of lactate accumulation and low rates of oxygen consumption, suggesting a potential susceptibility to inhibitors of glycolysis. In all ten human tested neuroblastoma tumor cell lines, 3-BrOP induced cell death via apoptosis in a dose and time dependent manner. Furthermore, 3-BrOP-induced depletion of ATP levels correlated with decreased neuroblastoma cell viability. In a mouse neuroblastoma xenograft model, glycolysis inhibition with 3-BrOP demonstrated significantly reduced final tumor weight. In neuroblastoma tumor cells, treatment with 3-BrOP induced mTOR activation, and the combination of 3-BrOP and mTOR inhibition with rapamycin demonstrated synergistic efficacy. Based on these results, neuroblastoma tumor cells are sensitive to treatment with inhibitors of glycolysis, and the demonstrated synergy with rapamycin suggests that the combination of glycolysis and mTOR inhibitors represents a novel therapeutic approach for neuroblastoma that warrants further investigation.