Dallas, Michael J.

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.

Objective To evaluate the safety, immunogenicity, and efficacy of INO‐3107, a DNA immunotherapy designed to elicit targeted T‐cell responses against human papillomavirus (HPV) types 6 and 11, in adult patients with recurrent respiratory papillomatosis (RRP; NCT04398433). Methods Eligible patients required ≥2 surgical interventions for RRP in the year preceding dosing. INO‐3107 was administered by intramuscular (IM) injection followed by electroporation (EP) on weeks 0, 3, 6, and 9. Patients underwent surgical debulking within 14 days prior to first dose, with office laryngoscopy and staging at screening and weeks 6, 11, 26, and 52. Primary endpoint was safety and tolerability, as assessed by treatment‐emergent adverse events (TEAEs). Secondary endpoints included frequency of surgical interventions post‐INO‐3107 and cellular immune responses. Results An initial cohort of 21 patients was enrolled between October 2020 and August 2021. Fifteen (71.4%) patients had ≥1 TEAE; 11 (52.4%) were Grade 1, and 3 (14.3%) were Grade 3 (none treatment related). The most frequently reported TEAE was injection site or procedural pain ( n = 8; 38.1%). Sixteen (76.2%) patients had fewer surgical interventions in the year following INO‐3107 administration, with a median decrease of 3 interventions versus the preceding year. The RRP severity score, modified by Pransky, showed improvement from baseline to week 52. INO‐3107 induced durable cellular responses against HPV‐6 and HPV‐11, with an increase in activated CD4 and CD8 T cells and CD8 cells with lytic potential. Conclusion The data suggest that INO‐3107 administered by IM/EP is tolerable and immunogenic and provides clinical benefit to adults with RRP. Level of Evidence 3 Laryngoscope , 133:3087–3093, 2023