The Effect of Allergen Immunotherapy on Anti-viral Immunity in Patients With Allergic Asthma
Condition: Allergic Asthma Due to Dermatophagoides Pteronyssinus
MeSH terms: Asthma
Study type: Interventional
Phase: Phase 4

Summary: 
      Aim: To investigate the possible immune modulatory effects of allergen immunotherapy (AIT) on
      respiratory immunity in patients with allergic asthma (AA).

      Background: Allergic sensitization to aeroallergens is a common co-morbidity in asthma that
      is associated with more frequent and severe asthma attacks. The investigators have recently
      shown that patients with allergic asthma also have an increased risk of pneumonia, and hence
      allergy in asthma may be associated with a relative respiratory immunodeficiency. However,
      the increased risk was obliterated in patients treated with AIT.

      Methods: Patients with asthma sensitized to house-dust mite (HDM) is enrolled in a
      randomized, double-blind, placebo-controlled study of HDM-AIT. Patients will be scheduled for
      9 visits through 8 months including, randomization to 6 months of treatment with either
      HDM-AIT (Acarizax/Odactra) or placebo. Primary interferons (IFN) type I and III will be
      investigated in human bronchial epithelial cells as the primary outcome. Secondary outcomes
      such as: Inflammatory cytokines, immunologic phenotype and immunohistochemistry will be
      investigated in bronchial biopsies, blood, bronchoalveolar lavage fluid, sputum and HDM-patch
      biopsies as well as a thorough respiratory and allergic evaluation.

      Expected outcomes: The investigators expect that, patients with AA have 1) decreased
      production of anti-viral type I and III IFN and that AIT increases these measures. 2)
      Anti-bacterial response is reduced through IL12, ß-defensin and IFN-γ and that AIT increases
      these measures. 3) Lastly, the investigators expect that T-cell response is dysregulated
      (Th1↓1/Th2↑) in patients with AA and that these findings are modulated in an
      immuno-protective direction after AIT.

      Perspectives: This project will expand our understanding of the clinical significance of
      allergy in asthma in a completely novel direction and show how AIT may modulate the immune
      response to prevent infections.
    

Detailed description: 
      1.1 Background Respiratory viral infections are the major cause of acute worsening of asthma.
      Importantly too, these infections may also predispose to bacterial infections. Patients with
      allergic asthma suffer from more frequent lower respiratory tract infections, more severe and
      longer lasting lower respiratory tract symptoms compared to healthy controls. Hence, the need
      to use antibiotics may reflect in part the increased susceptibility to viral infection in
      allergic asthma. The investigators have recently demonstrated that patients with allergic
      asthma have an increased risk of being prescribed antibiotics for respiratory infections
      compared to non-allergic patients with asthma. Other studies have identified allergic
      sensitization and respiratory viral infections as synergetic risk factors in asthma
      exacerbations. These findings suggest a possible link between the allergic sensitization,
      asthma and an impaired immune response against respiratory infections. Furthermore, the
      investigators have found that allergen-specific immunotherapy (AIT) reduces the risk of being
      prescribed antibiotics for respiratory infections in patients with allergic asthma. These
      novel observations make it of interest to investigate mechanistic pathways in target cells
      subjected to AIT.

      In a recent study, investigating potential mechanisms involved in the interaction between
      allergen and viral infection the investigators found that house dust mite (HDM) impairs viral
      stimulus (TLR3)-induced type I and type III interferons in bronchial epithelial cells from
      asthmatic patients and similarly in an in vivo mouse model of asthma exacerbation. This novel
      finding was accompanied with a direct effect of HDM on reducing TLR3 glycosylation. Hence,
      HDM exposure in patients with allergic asthma may also contribute to a defect antiviral
      response by interfering with components important for the anti-viral signalling such as TLR3.
      Furthermore, the investigators have observed that HDM has a capacity to induce
      over-expression of upstream Th2 cytokines such as IL-33, which may contribute to asthma
      exacerbations. In our studies HDM stands out amongst different allergens in causing both
      release of inflammatory inducing damage-associated metabolic patterns and impaired interferon
      response.

      Inferentially, in this study the investigators will have the unique opportunity to examine
      effects of human in vivo HDM-AIT on the bronchial epithelial cell production of type I and
      type III interferons as well as the balance between Th1/and Th2 inflammation in response to
      viral and bacterial triggers. The investigators speculate that exposure to HDM-allergen may
      predispose to asthma exacerbations by causing dysregulation of the anti-viral interferon
      system as well as Th1/and Th2 inflammation and then that desensitization of patients with
      HDM-sensitive allergic asthma (AA) increases innate interferon response.

      1.2 Hypothesis

        1. Viral induced type I and type III IFN is increased in HBECS from patients with allergic
           asthma sensitized to HDM, after 24 weeks of Acarizax.

        2. Viral induced type I and III IFN response is impaired in HBECs from patients with
           allergic asthma sensitized to HDM, before 24 weeks of Acarizax.

      1.3 Investigational Medical Product (IMP): ACARIZAX Acarizax is sublingual allergen
      immunotherapy (SLIT) for the treatment of HDM allergic rhinitis (AR) and allergic asthma
      (AA). Acarizax is composed of standardized allergen extract from the HDMs' Dermatophagoides
      pteronyssinus and Dermatophagoides farina.

      The efficacy of Acarizax has been tested in randomized, double-blinded, placebo-controlled
      trials as add-on treatment for the best maintenance treatment for AR and AA. The clinical
      effect of Acarizax has been demonstrated 8-14 weeks after initiation of treatment and data on
      clinical effect is available for up to 18 months of treatment. Acarizax was found to reduce
      time to first exacerbation (hazard-ratio 0.7) in patients with AA. Acarizax has been shown to
      reduce daily mean inhaled corticosteroid (budesonide) by 81 microgram/day (95% CI:
      27-136microgram/day). In AR, Acarizax has been shown to reduce Total Combined Rhinitis Score
      (TCRS). A meta-analysis on the efficacy of AIT on atopic dermatitis shows moderate level of
      efficacy. Hence, we will be studying the potential change in the immunologic phenotype as an
      exploratory outcome.

      AIT has been known for more than 100 years as a potential curative and specific treatment for
      allergic diseases. The mechanism by which AIT works is poorly understood but a key target is
      likely modulation of immunopathology. Dysregulation of the immune system is thought to play
      an essential role in atopic diseases and is influenced by multiple complex regulatory
      mechanisms. Well-established immune modulatory effects of AIT are classified into following
      type of events:

      Table 1. Mechanisms of AIT Order of events Events Change Time to initial change

        1. Basophil- and Mast cell activity and degranulation of IgE mediated histamine release
           Decrease Immediately

        2. Induction of allergen-specific Treg- and Breg cells and suppression of allergen specific
           Th1 and Th2 cells Increase Days to weeks

        3. Specific IgE Early increase followed by chronic decrease to baseline Weeks to years

        4. Specific IgG4 Continuously increase throughout treatment duration Weeks

        5. Tissue resident eosinophils, basophils and mast cells and release of their mediators
           Decrease Months

        6. Type 1 skin reactivity decrease Months

      1.4 Rationale

      Anti-viral immunity Interferons (IFNs) are essential cytokines in the anti-viral defence.
      IFN's are produced by many cell types in the lungs where human bronchial epithelial cells
      (HBECs) and plasmacytoid dendritic cells (pDCs) are the main producers. The major effects of
      IFNs include blocking of viral invasion into neighbour cells by cleaving viral nucleic acid
      and inhibiting viral replication and inducing apoptosis in affected cells. HBECs are critical
      for the development of a sufficient innate immune response to viral infection. Increasing
      evidence suggest that HBECS from patients with asthma and allergic asthma exhibit an impaired
      ability to secrete type I (IFN-beta), and III (IFN-lambda) interferons at viral infection. In
      addition, IFN-beta and IFN-lambda may inversely correlate with the level of Type 2
      inflammation in the airway epithelium.

      pDCs are essential effectors of the primary innate immune defence against viral infections,
      releasing large amounts of IFN-alpha, and driving Th1 polarisation of CD4 lymphocytes.
      However, pDCs also play an important role as antigen-presenting cells, by which they may
      drive a Th2 polarisation, increasing IgE-production in B-cells and potential cross-linking of
      FcepsilonR1-alpha receptors. Interestingly, it has recently been demonstrated that viral
      induced IFN-alpha release was diminished by activation of the FcepsilonR1-alpha receptor on
      the pDC by allergen exposure, suggesting a potential link between allergy and a reduced viral
      defence. In patients with allergic asthma viral induced IFN-alpha release was impaired in
      PBMC's indicating a more systemic impact in response to bronchial infection.

      AIT: Mechanisms leading to suppression of allergic inflammation In general, it is
      acknowledged that Th2 / Treg cells tolerance is decisive for the development or suppression
      of allergic inflammation. Treg cells secrete high amounts of essential suppressor cytokines
      IL-10 and TGF-beta. These cytokines contribute to the control of Th2 mediated allergic
      disease in various ways. Treg cells regulates B-cells by inducing a competitive IgG4 and IgA
      response resulting in suppression of IgE. Furthermore, Treg cells may suppress activation and
      degranulation of mast cells, basophils and eosinophils. Lastly Treg cells, suppress Th2 cells
      homing to tissue and epithelial cell activation and production of proinflammatory cytokines.
      Breg cells control excessive inflammatory responses through secretion of IL-10, supports
      differentiation of Treg cells and induces synthesis of IgG4. These effects may be involved in
      response to AIT and correlate with clinical improvement. Thus, AIT may result in a decrease
      of bronchial, nasal and conjunctival hyperreactivity, which is a reflection of decrease in
      underlying mucosal inflammation. Anti-IgE treatment ameliorates the seasonal variations in
      asthma exacerbations associated with virus infections, which may be related to an increase in
      the initial interferon response to viral infections. We thus speculate, that the potential
      immunomodulatory effects of AIT resulting in lowered risk of prescription antibiotics is the
      net result of alteration in allergen-induced mucosal Th-2 inflammation, mediated by an
      increase in primary IFN defence responses to viral infections.

      6.6 Study governance and oversight

      6.6.1 Study Site Bispebjerg Hospital, Dep. of Respiratory Medicine Bispebjerg Bakke 23,
      Entrance 66 DK - 2400 Copenhagen NV Denmark Phone: (+45) 35 31 35 69 Fax: (+45) 35 31 21 79

      6.6.12 Additional sites of analyses

        -  Department of Immunology and Microbiology, University of Copenhagen

        -  Department of Respiratory Immunopharmacology University of Lund

        -  ALK-Abelló A/S, Boege Allé 6-8, 2970 Hoersholm

      6.6.13 Study registration and authorities Study code: VITAL EudraCT: 2019-003261-18 Ethics
      Committee journal number: H-19052148 Danish Medicines Agency: 2019-003261-18
      ClinicalTrial.gov: NCT04100902

      6.6.14 Steering Committee Christian Uggerhoej Woehlk, M.D., Ph.D.-student Asger Sverrild,
      M.D., Ph.D. Charlotte Menné Bonefeld, Professor Lena Uller Ass. Professor Steen Roenborg,
      M.D. Ph.D. Celeste Porsbjerg, Professor, M.D.

      6.6.15 Participants and collaborators

        1. Pharmacy: Region Hovedstadens Apotek, Marielundvej 25, 2730 Herlev, Denmark.

        2. Peter Arvidsson, M.D., PhD.: ALK-Abelló Nordic A/S, Kungbacke Sweden

        3. Peter Sejer Andersen: ALK-Abelló A/S, Boege Allé 6-8, Bygn. 9, 2970 Hoersholm

        4. Peter Adler Würtzen, Senior Specialist, PhD: ALK-Abelló A/S, Boege Allé 6-8, Bygn. 9,
           2970 Hoersholm

      8. STATISTICAL ANALYSES 8.1 Sample size estimate Sample size calculations have been carried
      out using G-Power software (Behaviour Research Methods 2007 Faul et al).

      8.1.1 Primary outcome:

      To our knowledge there is no preceding studies investigation the relationship between AIT
      treatment and change in IFN-response in HBECS. The investigators have previously shown that
      treating human airway epithelium in vitro with azithromycin increase the IFN-response to
      viral infection mimics in a dose-dependent manner. Fold-change in INF-β was 1.55 (SD 0.555)
      at the given concentration. Given a significant change in IFN-β from week 0 to week 24 is set
      to be a 1.55-fold change with SD of 0.555, that alpha is set to 0.05, and the power to 0.80,
      in a two-sided test design, the calculation would look like this:

      Mean (fold change in INF-β) group 1 (placebo): 1 Mean (fold change in INF-β) group 2
      (Acarizax): 1.55 SD: 0.55 16 subjects will be needed in each study arm. Assuming a drop-out
      of 20%, a minimum of 40 subjects in total will need to be randomized.

      8.2 Definitions of analysis sets 1) Populations for analysis:

        1. Intention-to-treat population: All randomized subjects who receive at least one dose of
           Acarizax or placebo. A comparison of the treatment groups will be performed.

      2) Population for analysis based on adherence ≥ 80% to treatment.

      1. Intention-to-treat population: All randomized subjects with adherence ≥ 80% to Acarizax
      therapy or placebo. A comparison of the treatment groups will be performed.

      8.2.1 Efficacy analysis set Intention-to-treat population (as defined in 8.2).

      8.2.2 Safety analysis set All patients who receive at least one dose of Acarizax/placebo.

      8.3 Methods for statistical analyses All data limited to primary and key secondary outcomes
      will be analysed using SPSS v. 14 or later. all data are reported as median values with
      interquartile ranges and were analysed using non-parametric tests. Data within each group
      (Acarizax and placebo) will be analysed using linear mixed model or ANCOVA. Statistical
      differences between the Acarizax and placebo groups will be determined using the Mann -
      Whitney U test for unrelated samples. Skewed-data will be log-transformed before analysis and
      reported using median and 25/75 % percentiles. Parametric data will be analysed using the
      above-mentioned methods. Categorial data will be analysed using χ²-test. Statistical
      significance is defined as p<0.05. The data from the subject dropping out will still be used
      in the analysis using methods for handling of missing data.

      8.3.1 Analysis of the primary variable(s) The fold-change in IFN-β and IFN-λ are analysed
      before and after RV infection and/or poly(I:C) stimulation from V3 to V12 and will be
      compared between intervention and placebo treatment. The investigators expect parametric
      distribution of data.

      The calculation will be as follows:

        1. deltaIFN-β: IFN-β V12 - IFN-βV3

        2. Mean fold-change IFN-β: Sum of individual changes / N

      Supportive primary objectives are calculated between intervention and placebo treatment
      groups:

        1. Change in expression of IFN-λ measured in ρg/ml (ELISA) and reported as fold change mean
           ± SD

        2. Change in viral load/TCID50 assay measure reported as fold change mean ± SD

      8.3.2 Analysis of the secondary variable(s)

        -  Changes in IFN-responses will be analysed using same procedure as analysis of the
           primary outcome.

        -  Cytokines will be analysed accordingly to the method described in 8.3.1 and reported as
           ρm/ml (or similar quantitative method) and reported as fold change mean ± SEM

        -  Change in IFN-β/TSLP ratio and reported in %.

        -  The change, expressed as a ratio, in number of airway submucosal, muscle and epithelium
           mast cells, eosinophils, neutrophils, NK-cells, (MCT, MCTC and MCCPA3) per mm2
           determined by microscopic evaluation of mucosa biopsies and epithelial brushings from V2
           to V7.

      8.3.3 Interim analysis No interim analysis is planned.

      8.3.4 Use of database REDCap will be used for online CRF data management.

      9. STUDY AND DATAMANGEMENT 9.1 Economy

      The scientific ideas of protocol are based solely on the work of members of the steering
      committee. None of the members of the steering committee have any commercial interest in the
      results of this study. As per 01.08.19, the project has received:

        1. Unrestricted grant from ALK-Abelló Nordic of (900.000dkk)

        2. Unrestricted grant from Sawmill owner Jeppe Juhl and wife Ovita Juhls memorial fund
           (250.000 dkk).

        3. HARBOEFONDEN: DKK 200.000

        4. Pharmaxis: Osmohale Mannitol Challenge tests

      9.2. Subject reimbursement Each subject completing the study will receive a total of 6 months
      of Acarizax treatment equivalent to approximate 5.500 dkk. Subject randomized to Acarizax arm
      will not be furtherly compensated.

      9.2.1 Source data Will be filed at Bispebjerg Hospital, Denmark (study site) in accordance
      with The Danish Data Protection Agency laws. Source data will be kept for a maximum of 20
      years from (01.09.2019). At this point all source data will be destroyed.

      9.2.2 Study agreements All agreements relating to the study will be available in the trial
      master file (TMF).

      9.2.3 Archiving of study documents Documents will be archived at Bispebjerg Hospital, Denmark
      (study site) in accordance with GCP and The Danish Data Protection Agency laws.

      9.3 Monitoring of the study

      The study will be monitored by the GCP Unit in Copenhagen:

      Copenhagen University Hospital GCP-unit Bispebjerg Hospital, Building 51, 3.fl Bispebjerg
      Bakke 23 DK - 2400 København NV Denmark Phone: (+45) 3531 3887 E-mail:
      gcp-enheden.bispebjerg-frederiksberg-hospitaler@regionh.dk www.gcp-enhed.dk.
    

Intervention name(s): ODACTRA 12 SQ-HDM Sublingual Tablet; Placebo sublingual tablet
Intervention type(s): Drug; Drug
Intervention description(s): Subjects are randomized to either HDM-AIT or Placebo for 24 weeks of therapy; Subjects are randomized to either HDM-AIT or Placebo for 24 weeks of therapy
Other intervention name(s): 12-SQ-HDM sublingual tablet
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary purpose: Treatment
Keywords: Allergic asthma; Allergen Immunotherapy; Anti-viral immunity; House dust mite