Gillespie, Elisabeth

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.

Abstract Chronic hepatitis C can lead to cirrhosis and hepatocellular carcinoma. We studied the safety and immunogenicity of a novel therapeutic hepatitis C virus (HCV) genotype 1a/1b consensus DNA vaccine, INO-8000, encoding HCV NS3, NS4A, NS4B, and NS5A proteins alone or co-administered with DNA-encoding IL12 (INO-9012), a human cytokine that stimulates cellular immune function, in individuals with chronic hepatitis C. This was a phase I, multisite dose-escalation trial with an expansion cohort evaluating doses of 0, 0.3, 1.0, and 3.0 mg of INO-9012 (IL12 DNA) as an addition to 6.0 mg of (INO-8000; HCV DNA vaccine). Vaccines were administered by intramuscular injection followed by electroporation at study entry and at weeks 4, 12, and 24. HCV-specific CD4+ and CD8+ T-cell immune responses were measured by IFNγ ELISpot and flow cytometry–based assays. Transient, mild-to-moderate injection site reactions unrelated to IL12 DNA dose were common. Increases in HCV-specific IFNγ production occurred in 15/20 (75%) participants. Increases in the frequency of HCV-specific CD4+ and CD8+ T cells occurred at all dose levels, with the greatest increases seen at 1.0 mg of INO-9012. HCV-specific CD8+ and CD4+ T-cell activities increased in 16/18 (89%) and 14/17 (82%) participants with available data, respectively. The vaccine regimen was safe and induced HCV-specific CD4+ and CD8+ cellular immune responses of modest magnitude in most HCV-infected participants. The addition of 1.0 mg of IL12 DNA provided the best enhancement of immune responses. The vaccine regimen had little effect on controlling HCV viremia. Prevention Relevance: The administration of IL12 DNA along with a hepatitis C viral antigen DNA vaccine enhanced the HCV-specific immune responses induced by the vaccine in individuals with chronic hepatitis C, an important cause of hepatocellular carcinoma. IL12 could be an effective adjuvant in vaccines targeting HCV and other oncogenic viruses.