Skolnik, Jeffrey

ABSTRACT Objective To evaluate the long‐term safety and clinical effect of INO‐3107 immunotherapy in adults with recurrent respiratory papillomatosis (RRP). Methods RRP‐002 was a retrospective, observational extension study that followed patients enrolled in the 52‐week RRP‐001 study. Patients with moderate to severe juvenile or adult‐onset RRP who had undergone ≥ 2 surgical interventions in the year preceding dosing were eligible for enrollment in RRP‐001. Participants underwent surgical debulking within 14 days prior to initial dosing and then received INO‐3107 on Day 0, Weeks 3, 6, and 9. Efficacy assessments during RRP‐002 follow‐up were the frequency of surgical interventions and alternative medication use. The safety evaluation included reported serious adverse events (SAEs). Results Twenty‐eight (28) of 32 participants from the 52‐week RRP‐001 study were enrolled in RRP‐002. The median follow‐up time for RRP‐002 was 1.8 years (range: 1.2–2.4 years) for a total median assessment time of 2.8 years (range: 1.0–3.5 years). There were no SAEs or long‐term safety concerns identified. The mean number of surgeries was reduced from 4.1 in the pre‐treatment period to 1.7 in the first year post‐INO‐3107 treatment (Year 1) to 0.9 in the second year (Year 2). The complete response rate (0 surgeries per year) increased from 28% (9/32) in Year 1 to 50% (14/28) in Year 2. Conclusion INO‐3107 is well tolerated and provides a continued clinical effect against HPV‐6 and 11 RRP that results in further reduction of the surgical burden observed in Year 1. These data support the role of INO‐3107 immunotherapy for adult patients with RRP. Level of Evidence: III.

Abstract Recurrent respiratory papillomatosis (RRP) is a debilitating chronic disease of the airway caused by Human Papillomavirus (HPV). Here we describe the efficacy, safety, and immunogenicity from a Phase 1/2 trial of INO-3107, a DNA immunotherapy designed to elicit T-cell responses against HPV-6 and HPV-11, in adults with RRP (NCT04398433). Thirty-two eligible patients with HPV-6 and/or HPV-11 RRP, who required ≥2 surgical interventions in the year preceding dosing, were administered 4 doses of INO-3107 by intramuscular (IM) injection followed by electroporation (EP). The primary endpoint was safety and tolerability. Efficacy and immunology endpoints included the frequency of surgical interventions in the year following the first dose of INO-3107 and assessment of immune responses. The majority (26/32; 81%) of patients experienced a reduction in the number of surgeries in the year following initiation of treatment with INO-3107, when compared with the year prior. Peripheral blood assessments revealed HPV-6 and HPV-11 antigen-specific T-cell induction, inclusive of cytolytic CD8+ T-cells. RNA sequencing identified the presence of an inflammatory response in patient papillomas after treatment with INO-3107, inclusive of cytolytic CD8+ T-cell signatures. T-cell receptor sequencing revealed emergent T-cell clones in the blood and assessment of airway tissue confirmed trafficking of these clones to papillomas, which was associated with clinical benefit. Treatment was well tolerated, with 13/32 (41%) patients reporting a treatment-related adverse event (AE), all of which were low-grade. INO-3107 provides clinical benefit to adults with HPV-6 and/or HPV-11 associated RRP, is well tolerated, and generates an antigen-specific immune response against HPV. Importantly, treatment-induced peripheral T-cell responses traffick to airway tissue and are associated with clinical response, consistent with the proposed mechanism of action.

Background Human telomerase reverse transcriptase (hTERT) is frequently classified as a ‘universal’ tumor associated antigen due to its expression in a vast number of cancers. We evaluated plasmid DNA-encoded hTERT as an immunotherapy across nine cancer types. Methods A phase 1 clinical trial was conducted in adult patients with no evidence of disease following definitive surgery and standard therapy, who were at high risk of relapse. Plasmid DNA encoding one of two hTERT variants (INO-1400 or INO-1401) with or without plasmid DNA encoding interleukin 12 (IL-12) (INO-9012) was delivered intramuscularly concurrent with the application of the CELLECTRA constant-current electroporation device 4 times across 12 weeks. Safety assessments and immune monitoring against native (germline, non-mutated, non-plasmid matched) hTERT antigen were performed. The largest cohort of patients enrolled had pancreatic cancer, allowing for additional targeted assessments for this tumor type. Results Of the 93 enrolled patients who received at least one dose, 88 had at least one adverse event; the majority were grade 1 or 2, related to injection site. At 18 months, 54.8% (51/93) patients were disease-free, with median disease-free survival (DFS) not reached by end of study. For patients with pancreatic cancer, the median DFS was 9 months, with 41.4% of these patients remaining disease-free at 18 months. hTERT immunotherapy induced a de novo cellular immune response or enhanced pre-existing cellular responses to native hTERT in 96% (88/92) of patients with various cancer types. Treatment with INO-1400/INO-1401±INO-9012 drove hTERT-specific IFN-γ production, generated hTERT-specific CD4+ and CD8+ T cells expressing the activation marker CD38, and induced hTERT-specific activated CD8 +CTLs as defined by cells expressing perforin and granzymes. The addition of plasmid IL-12 adjuvant elicited higher magnitudes of cellular responses including IFN-γ production, activated CD4+ and CD8+ T cells, and activated CD8+CTLs. In a subset analysis of pancreatic cancer patients, the presence of immunotherapy-induced activated CD8+ T cells expressing PD-1, granzymes and perforin correlated with survival. Conclusions Plasmid DNA-encoded hTERT/IL-12 DNA immunotherapy was well-tolerated, immune responses were noted across all tumor types, and a specific CD8+ phenotype increased by the immunotherapy was significantly correlated with survival in patients with pancreatic cancer.