The tumor microenvironment state associates with response to HPV therapeutic vaccination in patients with respiratory papillomatosis

Recurrent respiratory papillomatosis: Immunological mechanisms involved in recurrence

Recurrent respiratory papillomatosis is a benign neoplastic pathology in children, young people, and adults. It causes a significant deterioration in the quality of life, with symptoms typically referred to as dysphonia and hoarseness. This disease, with variable clinical courses ranging from spontaneous resolution to dissemination of the lower airway or airway obstruction that puts the individual's life at risk, characteristically requires multiple surgical interventions. Therapy with adjuvant drugs does not yet prove the effectiveness necessary to limit the recurrence and need for surgical reoperation in this condition. The review aimed to synthesize the immunopathogenic mechanisms of relapse in recurrent respiratory papillomatosis published in the current literature and the immunological implication of risk factors and treatment.

Disease Control and Voice Outcomes Following Treatment With PRGN-2012 in Adults With Recurrent Respiratory Papillomatosis

OBJECTIVE

More than 50% of adult patients with recurrent respiratory papillomatosis that receive PRGN-2012 develop a protocol-defined complete response. The relationship between papilloma disease control and change in voice handicap following PRGN-2012 treatment requires clarity as patients and providers consider treatment.

STUDY DESIGN

A post hoc study of pretreatment and post treatment Derkay and Voice Handicap Index-10 (VHI-10) data collected prospectively as predetermined exploratory outcome measures on a completed single-arm, single-cohort, phase 1/2 registration clinical trial of PRGN-2012 monotherapy. All patients (n = 38) that were enrolled and treated were included in this study. Patients underwent prospective collection of recorded clinical nasopharyngolaryngoscopy and were administered a VHI-10 questionnaire before, during, and after treatment with PRGN-2012. Fisher's exact test, Wilcoxon rank sum test, Spearman's correlation, and multiple linear regression analyses were used to associate demographic and clinical variables to clinical response (CR) to PRGN-2012 treatment. Wilcoxon rank sum and Spearman's correlation tests were performed to compare change in anatomic Derkay to reduction in clinically-indicated interventions and VHI-10 scores after PRGN-2012 treatment compared to before treatment.

RESULTS

Greater reduction in anatomic Derkay score associated with greater percent reduction in clinically-indicated interventions after PRGN-2012 treatment (r = 0.68, P = 0.0001). Greater reduction in anatomic Derkay score significantly associated with greater reduction in VHI-10 score (r = 0.81, P < 0.0001). No association (r = 0.10, P = 0.5586) was observed between the number of clinically-indicated interventions required in the 12 months prior to treatment and CR. A reduced number of total lifetime clinically-indicated interventions associated with greater CR (r = 0.46, P = 0.0037) in univariate analysis, but the significance of this relationship was lost on multi-variate analysis (P = 0.184) adjusting for multiple co-variates.

CONCLUSIONS

These data link greater papilloma disease control with reduced need for clinically indicated procedures and reduced voice handicap after PRGN-2012 treatment independent of short- or long-term measures of disease severity.

PRGN-2012 gene therapy in adults with recurrent respiratory papillomatosis: a pivotal phase 1/2 clinical trial

BACKGROUND

Recurrent respiratory papillomatosis (RRP) is a rare debilitating condition caused by chronic infection with human papillomavirus (HPV) type 6 or 11. Papillomas develop in the aerodigestive tract, leading to significant voice disturbance and airway obstruction. No systemic treatment currently exists. We aimed to assess the safety and clinical activity of PRGN-2012 in adult patients with RRP treated at the recommended phase 2 dose.

METHODS

This was a single-centre, single-arm, phase 1/2 trial. Adult patients aged 18 years or older with RRP who required three or more interventions in the 1 year before treatment received adjuvant PRGN-2012 on day 1 following surgical debulking of disease, and on days 15, 43, and 85. Primary outcome measure was complete response rate, defined as the percentage of patients who did not require an intervention to control RRP in the 12 months after treatment. Safety outcomes included treatment-related adverse events. This study is registered ClinicalTrials.gov (NCT04724980).

FINDINGS

From March 16, 2021, to June 1, 2023, 38 patients were enrolled and received the 12-week treatment course. Among the 35 patients treated at the recommended phase 2 dose of 5×1011 particle units, 18 (51%) of 35 patients had a complete response (95% CI 34-69) with the median duration of complete response yet to be reached. Adverse events were mild and included grades 1-2 injection site reaction (34 [97%] of 35), fatigue (28 [80%] of 35), chills (25 [71%] of 35), and fever (24 [69%] of 35).

INTERPRETATION

PRGN-2012 treatment resulted in complete response in 51% of the patients treated and was safe. Based on these positive pivotal study results, a biologics license application to the US Food and Drug Administration (FDA) is planned, positioning PRGN-2012 to be an FDA-approved medical treatment for adult patients with RRP.

FUNDING

National Institutes of Health.

PRGN-2009 and bintrafusp alfa for patients with advanced or metastatic human papillomavirus-associated cancer

BACKGROUND

This first-in-human phase 1 study (NCT04432597) evaluated the safety and recommended phase 2 dose (RP2D) of PRGN-2009, a gorilla adenoviral-vector targeting oncoproteins E6, E7 (human papillomavirus (HPV)16/18) and E5 (HPV16), as monotherapy (Arm 1A) and combined with the bifunctional TGF-β "trap"/anti-PD-L1 fusion protein bintrafusp alfa (BA; Arm 1B), in patients with recurrent/metastatic HPV-associated cancer.

METHODS

Patients with ≥ 1 prior treatment (immunotherapy allowed) received PRGN-2009 (1 × 1011 particle units or 5 × 1011 particle units, subcutaneously) every 2 weeks for 3 doses, then every 4 weeks (Arm 1A), or PRGN-2009 (RP2D, schedule per Arm 1A) and BA (1200 mg, intravenously) every 2 weeks (Arm 1B). Primary endpoints were safety and RP2D of PRGN-2009; secondary objectives included overall response rate (ORR) and overall survival (OS).

RESULTS

Seventeen patients were treated. In Arm 1A (n = 6) there were no dose limiting toxicities or grade 3/4 treatment-related adverse events (TRAEs), 5 × 1011 PU was selected as RP2D, no responses were observed, and median OS (mOS) was 7.4 months (95% CI 2.9-26.8). In Arm 1B (n = 11), grade 3/4 TRAEs occurred in 27% of patients, ORR was 20% for all patients (22% in checkpoint-resistant patients), and mOS was 24.6 months (95% CI 9.6-not reached). Multifunctional HPV-specific T cells were increased or induced de novo in 80% of patients and not impacted by anti-vector antibodies. Higher serum IL-8 at baseline associated with shorter OS.

CONCLUSIONS

PRGN-2009 was well tolerated, and immune responses were observed to PRGN-2009. Encouraging anti-tumor activity and OS were noted in the combination with BA arm, consisting mainly of checkpoint-resistant patients. Trial Registration ClinicalTrials.gov Identifier: NCT04432597.

Major Human Leukocyte Antigen Expression in Respiratory Papillomatosis Clinical Specimens

OBJECTIVES

Prior studies have reported low or absent major HLA class I expression on respiratory papilloma cells, conflicting with the recent clinical success of immunotherapy designed to activate HPV-specific T cells in patients with recurrent respiratory papillomatosis (RRP). We aimed to determine major human leukocyte antigen (HLA) class I expression on respiratory papilloma cells in untreated RRP clinical specimens using contemporary techniques.

METHODS

Formalin-fixed, paraffin-embedded RRP sections were subjected to signal-amplified multispectral immunofluorescence using the OPAL system to determine major and minor HLA class I expression, and digitally scanned slides were analyzed using digital pathology software. Positive and negative controls were used to optimize primary antibody conditions.

RESULTS

All samples harbored major HLA class I expression on varying proportions of papilloma cells. Considering all samples, major HLA class I expression was observed on the majority (74%) of papilloma cells. Nearly all (98%) papilloma infiltrating immune cells were positive for major HLA class I expression, serving as an internal control for each stained sample. Major HLA class I negative papilloma cells were enriched in the apical, suprabasal layers compared to the basal layers of the papillomatous epithelium, suggesting an association with the epithelial cell differentiation state. Fewer papilloma cells inconsistently expressed the minor HLA class I HLA-E across the basal and suprabasal epithelial layers.

CONCLUSION

Papilloma cells express major HLA class I molecules. Using contemporary immunofluorescent techniques with signal amplification that likely provide improved sensitivity, these results clarify the major HLA class I expression status on papilloma cells in clinical specimens.

LEVEL OF EVIDENCE

N/A.

Third Proceedings of The North American Airway Collaborative (NoAAC): Consensus Statement on Trial Design for Airway Stenosis

Importance

Airway stenosis is a rare but debilitating disorder that significantly degrades the quality of life in affected patients. Treatments are primarily surgical, and disease management lacks established medical therapies. The North American Airway Collaborative held its third symposium at The Johns Hopkins Hospital in Baltimore, Maryland, on April 15, 2024, focused on strategies to advance the care of these patients. The proceedings summarize the discussion of trial design in airway stenosis and the resulting North American Airway Collaborative consensus regarding clinical end points for rigorous study of novel therapies.

Observations

The lectures and panels centered on the translation of a growing body of preclinical data into therapeutic targets. Additionally, detailed discussion explored design of clinical trials to evaluate safety and efficacy of novel therapeutics. The need for a consensus regarding clinically meaningful end points in airway stenosis was identified to facilitate the comparison of outcomes across institutions and future multi-institutional trials.

Conclusions and Relevance

The group achieved consensus regarding change in peak expiratory flow as the primary clinical end point in airway stenosis. Additional clinical measures, such as disease recurrence (identified as time to recurrent intervention), anatomical characterization of subglottic scar via axial computed tomography imaging, and patient-reported outcome measures (Clinical COPD Questionnaire [CCQ], Voice Handicap Index-10 [VHI-10], Eating Assessment Tool-10 [EAT-10], and 12-Item Short-Form Health Survey, version 2 [SF-12]) were identified as essential secondary outcomes.

DNA immunotherapy for recurrent respiratory papillomatosis (RRP): phase 1/2 study assessing efficacy, safety, and immunogenicity of INO-3107

Recurrent respiratory papillomatosis (RRP) is a chronic airway disease caused by Human Papillomavirus (HPV). INO-3107, DNA immunotherapy designed to elicit T-cells against HPV-6 and HPV-11, was evaluated in a 52-week Phase 1/2 study for efficacy, safety, and immunogenicity (NCT04398433). Thirty-two eligible adults with HPV-6 and/or HPV-11 RRP, requiring ≥2 surgical interventions in the year preceding dosing were enrolled between October 2020 and November 2021 and administered 4 INO-3107 doses by intramuscular injection followed by electroporation. The primary endpoint was safety and tolerability, as assessed by treatment-emergent adverse events (TEAEs). Secondary endpoints included surgical intervention frequency and change in RRP Severity Score (modified) post-INO-3107 and assessment of immune responses. 81% (26/32) of patients experienced surgery reduction following INO-3107 compared with the year prior to treatment. Blood assessments revealed HPV-6 and HPV-11 antigen-specific T-cell induction. RNA sequencing identified an inflammatory response in papillomas, inclusive of cytolytic CD8 + T-cell signatures. T-cell receptor sequencing revealed emergent T-cell clones in blood and confirmed trafficking to papillomas. Treatment-related adverse events (AEs) were reported in 13/32 (41%) patients, all low-grade. INO-3107 provides clinical benefit to HPV-6 and/or HPV-11-associated RRP adults and is well-tolerated. Importantly, treatment-induced peripheral T-cell responses traffic to airway tissue and are associated with clinical response.

A recent perspective on designing tumor vaccines for tumor immunology

With the rapid development of immunotherapy, therapeutic tumor vaccines, which aim to enhance the immunogenicity of tumor cells and activate the patient's immune system to kill tumor cells, as well as eliminate or inhibit tumor growth, have drawn increasing attention in the field of tumor therapy. However, due to the lack of immune cell infiltration, low immunogenicity, immune escape and other problems, the efficacy of tumor vaccine is often limited. Researchers have developed a variety of strategies to enhance tumor immune recognition, such as improving the immunogenicity of tumor antigens, selecting a suitable vaccine platform, or combining tumor vaccines with other anticancer treatments. In this review, we will deliberate on how to overcome the problem of therapeutic tumor vaccines, and discuss the up-to-date progress and achievements in the tumor vaccine development, as well as their future in cancer treatment.

A Consensus Statement on the Administration of Systemic Bevacizumab in Patients with Recurrent Respiratory Papillomatosis

OBJECTIVE

To provide detailed guidance on the administration of systemic bevacizumab in patients with recurrent respiratory papillomatosis (RRP) based on a detailed review of the scientific literature and a consensus of experts with real-world clinical experience.

METHODS

A bevacizumab consensus working group (N = 10) was composed of adult and pediatric otolaryngologists, adult and pediatric oncologists, and a representative from the RRP Foundation (RRPF), all with experience administering systemic bevacizumab in patients with RRP. After extensive review of the medical literature, a modified Delphi method-based survey series was utilized to establish consensus on the following key areas: clinical and patient characteristics ideal for treatment candidacy, patient perspective in treatment decisions, treatment access, initial dosing, monitoring, guidelines for tapering and discontinuation, and reintensifying therapy.

RESULTS

Seventy-nine statements were identified across nine critical domains, and 45 reached consensus [clinical benefits of bevacizumab (3), patient and disease characteristics for treatment consideration (7), contraindications for treatment (3), shared decision-making (incorporating the patient perspective) (5), treatment access (3), initial dosing and administration (8), monitoring (7), tapering and discontinuation (6), and reintensification (3)].

CONCLUSION

This consensus statement provides the necessary guidance for clinicians to initiate systemic administration of bevacizumab and represents a potential paradigm shift toward nonsurgical treatment options for patients with RRP.

LEVEL OF EVIDENCE

5 Laryngoscope, 134:5041-5046, 2024.

Pyroptosis in lung cancer: The emerging role of non-coding RNAs

Lung cancer remains an intractable malignancy worldwide, prompting novel therapeutic modalities. Pyroptosis, a lethal form of programmed cell death featured by inflammation, has been involved in cancer progression and treatment response. Simultaneously, non-coding RNA has been shown to have important roles in coordinating pattern formation and oncogenic pathways, including long non-coding RNA (lncRNAs), microRNA (miRNAs), circular RNA (circRNAs), and small interfering RNA (siRNAs). Recent studies have revealed that ncRNAs can promote or inhibit pyroptosis by interacting with key molecular players such as NLRP3, GSDMD, and various transcription factors. This dual role of ncRNAs offers a unique therapeutic potential to manipulate pyroptosis pathways, providing opportunities for innovative cancer treatments. In this review, we integrate current research findings to propose novel strategies for leveraging ncRNA-mediated pyroptosis as a therapeutic intervention in lung cancer. We explore the potential of ncRNAs as biomarkers for predicting patient response to treatment and as targets for overcoming resistance to conventional therapies.

Quantification and Functional Studies of Neutrophilic Cells Identifies Distinct Papilloma Phenotypes

OBJECTIVES

To characterize the distribution of immune cell subsets within laryngeal papillomas and to study the function of potentially immunosuppressive neutrophilic and regulatory T cells (Tregs).

METHODS

Fresh clinical papilloma specimens were collected at the time of surgery and studied with multiparameter flow cytometry. Papilloma infiltrating neutrophilic cells and Tregs were sorted and studied functionally with ex vivo T cell suppression assays.

RESULTS

Flow cytometric analysis of fresh laryngeal papillomas samples from 18 adult patients with recurrent respiratory papillomatosis revealed patterns in immune constituency between patients. Clearly divergent phenotypes based primarily on the degree of neutrophilic and T cell infiltration were identified. Relative neutrophilic cell enrichment and T cell depletion were observed in 50% of samples and neutrophilic cell depletion and T cell enrichment were observed in the others. Greater papilloma neutrophilic cell enrichment was positively associated with the number of clinically indicated interventions required in the 12 months prior to sample collection, linking papilloma neutrophil inflammation to disease severity. Functional assays revealed the ability of both papilloma infiltrating neutrophilic and Tregs to suppress T cell function at roughly equal magnitudes, but substantially increased infiltration of neutrophilic cells compared to Tregs across samples.

CONCLUSION

Neutrophilic cells are an important contributor to immunosuppression within the respiratory papilloma microenvironment. Given these data and the association between greater neutrophilic cell infiltration and lack of clinical response to therapeutic vaccination, additional study of strategies aimed at limiting neutrophilic cell infiltration or function within papillomas is warranted.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:3238-3244, 2024.

VEGF as a Key Actor in Recurrent Respiratory Papillomatosis: A Narrative Review

Recurrent respiratory papillomatosis (RRP) is a benign disease of the upper aerodigestive tract caused by human papillomavirus (HPV) types 6 and 11. The clinical course is unpredictable and some patients, especially younger children, experience a high rate of recurrence with a significant impact on their quality of life. The molecular mechanisms of HPV infection in keratinocytes have been extensively studied throughout the years, with particular regard to its role in causing malignant tumors, like cervical cancer and head and neck carcinomas. A minor but not negligible amount of the literature has investigated the molecular landscape of RRP patients, and some papers have studied the role of angiogenesis (the growth of blood vessels from pre-existing vasculature) in this disease. A central role in this process is played by vascular endothelial growth factor (VEGF), which activates different signaling cascades on multiple levels. The increased knowledge has led to the introduction of the VEGF inhibitor bevacizumab in recent years as an adjuvant treatment in some patients, with good results. This review summarizes the current evidence about the role of VEGF in the pathophysiology of RRP, the molecular pathways activated by binding with its receptors, and the current and future roles of anti-angiogenic treatment.

J. Ertl H. Preclinical Immunogenicity and Efficacy Studies for Therapeutic Vaccines for Human Papillomavirus-Type-16-Associated Cancer

The objective of this study was to conduct preclinical immunogenicity and efficacy studies with several therapeutic vaccines for human papillomavirus (HPV)-16-associated cancers expressing the early antigens E5, E6, and E7 with or without E2. The viral oncoproteins were either expressed by themselves as fusion proteins or the fusion proteins were inserted genetically into herpes simplex virus (HSV)-1 glycoprotein D (gD) which, upon binding to the herpes virus entry mediator (HVEM), inhibits an early T cell checkpoint mediated by the B and T cell mediator (BTLA). This, in turn, lowers the threshold for T cell activation and augments and broadens CD8+ T cell responses to the antigens. The fusion antigens were expressed by chimpanzee adenovirus (AdC) vectors. Expression of the HPV antigens within gD was essential for vaccine immunogenicity and efficacy against challenge with TC-1 cells, which express E7 and E6 of HPV-16 but neither E5 nor E2. Unexpectedly, inclusion of E2 increased both CD8+ T cell responses to the other oncoproteins of HPV-16 and the effectiveness of the vaccines to cause the regression of sizable TC-1 tumors.

The Larynx is Protected from Secondary and Vertical Papillomavirus Infection in Immunocompetent Mice

OBJECTIVE

Mouse papillomavirus MmuPV1 causes both primary and secondary infections of the larynx in immunocompromised mice. Understanding lateral and vertical transmission of papillomavirus to the larynx would benefit patients with recurrent respiratory papillomatosis (RRP). To test the hypothesis that the larynx is uniquely vulnerable to papillomavirus infection, and to further develop a mouse model of RRP, we assessed whether immunocompetent mice were vulnerable to secondary or vertical laryngeal infection with MmuPV1.

METHODS

Larynges were collected from 405 immunocompetent adult mice that were infected with MmuPV1 in the oropharynx, oral cavity, or anus, and 31 mouse pups born to immunocompetent females infected in the cervicovaginal tract. Larynges were analyzed via polymerase chain reaction (PCR) of lavage fluid or whole tissues for viral DNA, histopathology, and/or in situ hybridization for MmuPV1 transcripts.

RESULTS

Despite some positive laryngeal lavage PCR screens, all laryngeal tissue PCR and histopathology results were negative for MmuPV1 DNA, transcripts, and disease. There was no evidence for lateral spread of MmuPV1 to the larynges of immunocompetent mice that were infected in the oral cavity, oropharynx, or anus. Pups born to infected mothers were negative for laryngeal MmuPV1 infection from birth through weaning age.

CONCLUSION

Secondary and vertical laryngeal MmuPV1 infections were not found in immunocompetent mice. Further work is necessary to explore immunologic control of laryngeal papillomavirus infection in a mouse model and to improve preclinical models of RRP.

LEVEL OF EVIDENCE

NA Laryngoscope, 134:2322-2330, 2024.