The Art of Dosing for Subcutaneous Immunotherapy in North America

Subcutaneous immunotherapy (SCIT) is a long-established treatment option for allergic rhinoconjunctivitis. Proper dosing of the allergens is critical for the efficacy and safety of SCIT. Of the hundreds of liquid allergen extracts in the United States, effective and well-tolerated SCIT dosing has only been established for a small number. Thus, SCIT dosing remains largely empiric and continues to be, by necessity, an art. To highlight the complexity of SCIT dosing, this review summarizes the historical and current landscape of U.S. allergen extracts, differences among U.S. and European allergen extracts, allergen selection for SCIT, considerations for compounding of allergen extract mixtures, and recommended dosing. As of 2021, 18 standardized allergen extracts are available in the United States; all other extracts remain unstandardized without characterization of allergen content or potency. U.S. allergen extracts differ from European extracts in formulation and potency characterization. There is no standardized methodology for SCIT allergen selection, and interpretation of allergen sensitization is not straightforward. Compounding of SCIT mixtures requires consideration of potential dilution effects, allergen cross-reactivity, proteolytic activity, and additives. Probable effective dose ranges for SCIT are recommended in U.S. allergy immunotherapy practice parameters, although there are few studies using U.S. extracts supporting these doses as therapeutic. In contrast, optimized doses of sublingual immunotherapy tablets have been confirmed in North American phase 3 trials. The SCIT dosing for each patient remains an art that requires clinical experience and consideration of polysensitization, tolerability, compounding of allergen extract mixtures, and the range of recommended doses within the context of extract potency variability.

Anaphylaxis in Clinical Trials of Sublingual Immunotherapy Tablets

BACKGROUND

There is no consensus method to identify anaphylaxis in sublingual immunotherapy (SLIT) trials. Standardized Medical Dictionary for Regulatory Activities (MedDRA) queries (SMQs) are standardized groupings of MedDRA terms used in drug safety monitoring.

OBJECTIVE

To develop a method to identify potential anaphylaxis in SLIT-tablet trials using SMQ searches and case definitions of anaphylaxis adopted from the National Institute of Allergy and Infectious Disease.

METHODS

The SMQ search tool contained 2 criteria including treatment-emergent adverse events (AEs): (1) narrow MedDRA terms related to anaphylaxis and (2) all AEs with broad MedDRA terms from at least 2 of 3 categories (respiratory/skin/cardiovascular) occurring on the same day. Criteria were applied to a pooled data set of all subjects from 48 timothy grass, ragweed, house dust mite, and tree SLIT-tablet trials (SLIT-tablet, N = 8200; placebo, N = 7033). Additional search strategies were any treatment-emergent AE with MedDRA preferred term "hypersensitivity" and epinephrine administrations. Identified potential cases underwent blinded independent medical expert review. Nonanaphylaxis cases were designated local AEs or mild to moderate systemic reactions.

RESULTS

Using the SMQ search tool and after subsequent medical review, 8 anaphylaxis cases were identified; 3 were considered treatment-related, resulting in a proportion of anaphylaxis cases/subject of 0.02% (2 of 8200) with SLIT-tablet and 0.01% (1 of 7033) with placebo. One additional anaphylaxis case related to SLIT-tablet was identified by the preferred term "hypersensitivity." The 3 anaphylaxis cases associated with SLIT-tablet treatment were not life-threatening. The epinephrine administration rate was 17 of 8200 (0.2%) with SLIT-tablet treatment and 2 of 7033 (0.03%) with placebo.

CONCLUSIONS

SMQ search criteria for identifying potential anaphylaxis related to SLIT were developed. Anaphylaxis was rare for SLIT-tablets.

The Art of Immunotherapy

Selection of a patient with rhinitis/conjunctivitis or asthma for allergy immunotherapy (AIT) requires several decisions. First, does the patient's sensitization, pattern of exposure to an allergen, and degree of exposure to that allergen reasonably suggest a causal relationship? Does the level and duration of symptoms warrant the cost and inconvenience of immunotherapy, or is the patient motivated by the disease-modifying potential of AIT? If AIT is selected, is the choice to be greater safety and convenience with sublingual immunotherapy (SLIT) tablets, but with treatment probably limited to 2 or 3 allergens, or for subcutaneous immunotherapy where multiple allergen therapy is the rule and efficacy may be somewhat greater, at least initially, or does the physician go off-label into the unknowns of liquid SLIT? Are there extracts of sufficient potency to achieve likely effective doses? How does the physician deal with large local or systemic reactions, with gaps in treatment, with pollen seasons, and the use of premedication or cautionary prescription of epinephrine autoinjectors? How can adherence to AIT be improved? These and other questions are addressed in this paper.

Effect of intralymphatic allergen-specific immunotherapy on house dust mite in a murine model of allergic rhinitis

BACKGROUND

Intralymphatic immunotherapy (ILIT) is a promising alternative for the treatment of patients with allergic rhinitis, providing similar therapeutic efficacy to conventional allergen-specific immunotherapy (AIT). However, the allergic mechanism of ILIT is not completely known.

AIM

The aim of this study was to determine the efficacy of ILIT in a house dust mite (HDM) mouse model of allergic rhinitis.

METHODS

BALB/c mice were divided into four groups: G1, control without allergy; G2, allergy sensitized with HDM; G3, allergy with ILIT (starting with HDM 1.25 μg/mL); and G4, allergy with ILIT (starting with HDM 2.5 μg/mL). After the murine model of allergic rhinitis with HDM was established, mice were administered an intralymphatic injection through the inguinal lymph nodes with HDM.

RESULTS

ILIT decreased serum total IgE level and eosinophil infiltration in the nasal mucosa. ILIT also decreased the expression levels of IL-13, IL-25, IL-33, IFN-γ, IL-6, and IL-17, and increased the expression of FoxP3(+) T reg cells.

CONCLUSIONS AND SIGNIFICANCE

Our results suggest that ILIT regulates the specific immunotherapy immunologic mechanism by downregulating Th1, Th2, and Th17 cytokines and upregulating FoxP3(+) T reg cells in the HDM allergic mouse model.

Comparison of Standard, Cluster, and Rush Allergy Immunotherapy Buildup Protocols

BACKGROUND

Allergy immunotherapy (AIT) involves a dose-escalation phase following 1 of 3 protocols: standard, cluster, or rush. Although the cluster and rush protocols have been shown to decrease the time to reach maintenance dosing, there is a lack of direct comparison between the protocols.

OBJECTIVE

This study aimed to evaluate the differences in time to maintenance dosing and occurrence of adverse reactions among the dose-escalation protocols.

METHODS

A retrospective observation study of patients on AIT was conducted. Patients were categorized as participating in the standard, cluster, or rush buildup protocols. Patients on the rush protocol, unlike the standard and cluster protocols, were required to receive prednisone, montelukast, cetirizine, and famotidine on the rush day and first 2 weekly injections thereafter. Variables analyzed include patient demographics, time until maintenance dosing, rate of adverse reactions, treatments required for reactions, and AIT formulation.

RESULTS

Data were reviewed on 237 patients on the standard (n = 41), cluster (n = 122), and rush (n = 74) protocols. The maintenance dose was achieved faster with the rush (16.50 weeks) and cluster (19.33 weeks) buildup protocols than the standard (31.09 weeks) protocol (P < .001). There was no statistically significant difference between time to maintenance dosing when comparing the cluster and rush protocols (P = .322). Despite pretreatment with the rush protocol, the rate of systemic reactions was the same for the standard (9.76%), cluster (9.84%), or rush (14.86%) buildup protocols (P = .526).

CONCLUSION

Patients on the cluster buildup protocol for AIT achieved maintenance dosing in a comparable time frame as the rush protocol with a similar rate of systemic reactions and without the need for the pretreatment required with rush immunotherapy.

Efficacy of Japanese cedar pollen sublingual immunotherapy tablets for Japanese cypress pollinosis

Background

We previously demonstrated the efficacy of Japanese cedar (JC) pollen sublingual immunotherapy (SLIT) tablets for treating seasonal allergic rhinitis in a clinical trial (trial no. 206-2-1) that covered 5 pollen dispersal seasons from 2015 to 2019.

Objective

Our aim was to perform post hoc analysis of the 206-2-1 trial data to evaluate the efficacy of JC pollen SLIT tablets for patients with rhinitis induced by pollen from Japanese cypress (JCY), a related Cupressaceae species that has a pollen dispersal season overlapping with that of JC.

Methods

Data were analyzed for 240 patients who received placebo during the first pollen dispersal season in 2015, were then rerandomized to receive JC SLIT tablets (the PA group) or placebo (the PP group) for 18 months (the 2016 and 2017 dispersal seasons), and were observed untreated for 2 years (the 2018 and 2019 dispersal seasons). The PA and PP groups were assigned to "high" and "low" subgroups if their rhinitis symptoms were exacerbated/did not change or decreased, respectively, during the peak JCY pollen dispersal period in 2015. The mean total nasal symptom and medication scores and other outcomes were compared for the high-PP, high-PA, low-PP, and low-PA groups during the 2016 to 2019 peak JCY pollen dispersal periods.

Results

The mean total nasal symptom and medication scores were significantly lower for the high-PA and low-PA groups than for the corresponding PP groups over the 4 years of treatment and observation. JCY pollen-specific IgE levels increased in both PA groups.

Conclusion

JC pollen SLIT tablets effectively suppressed JCY pollinosis symptoms, supporting the clinical relevance of immunologic cross-reactivity between JC and JCY allergens.

Eight tips for the implementation of the first licenced peanut allergy oral immunotherapy into clinical practice

BACKGROUND

Shared learnings from the early use of novel therapies can aid in their optimization. The recent introduction of peanut oral immunotherapy (peanut OIT; Palforzia [Peanut (Arachis hypogaea) Allergen Powder-dnfp]) for peanut allergy addresses a significant unmet need but also highlights the requirement for consideration of several factors by both prescribers and patients.

OBJECTIVE

To provide guidance for prescribers of licenced peanut OIT to facilitate treatment delivery and improve outcomes.

METHODS

Clinicians with experience of licenced peanut OIT (United States n = 6, United Kingdom n = 1) participated in a series of interviews and group discussions designed to elicit tips for successful implementation.

RESULTS

Clinicians identified 8 tips that were considered the most relevant, practical, and impactful for prescribers of Peanut (Arachis hypogaea) Allergen Powder-dnfp: (1) preparing to provide treatment, (2) assessing the medical indication for treatment and (3) shared decision making, (4) staff education, (5) establishing office processes, (6) managing patient expectations and using anticipatory guidance, (7) optimising adherence and (8) maintaining flexibility throughout the treatment process. In addition, a range of supporting materials (e.g., checklists and action plans) are provided.

CONCLUSION

The introduction of a novel therapy often requires healthcare providers to modify or adopt practices to effectively employ the treatment. The provision of guidance based upon early real-world experiences of licenced peanut OIT may help inform clinical practice and improve treatment outcomes.

Long-term real-world effectiveness of allergy immunotherapy in patients with allergic rhinitis and asthma: Results from the REACT study, a retrospective cohort study

Background

Allergen immunotherapy (AIT) is the only causal treatment for respiratory allergy. Long-term real-life effectiveness of AIT remains to be demonstrated beyond the evidence from randomised controlled trials (RCTs).

Methods

REACT (Real world effectiveness in allergy immunotherapy) is a retrospective cohort study using claims data between 2007 and 2017. Study eligibility was a confirmed diagnosis of allergic rhinitis (AR), with or without asthma, and AIT. To ensure comparable groups, AIT-treated subjects were propensity score matched 1:1 with control subjects, using characteristic and potential confounding variables. Outcomes were analysed as within (pre vs post AIT) and between (AIT vs control) group differences across 9 years of follow-up (ClinicalTrial.gov: NCT04125888).

Findings

46,024 AIT-treated subjects were matched with control subjects and 14,614 were included in the pre-existing asthma cohort. AIT-treated subjects were 29·5 (16·3) years and 53% were male. Compared to pre-index year, AIT was consistently associated with greater reductions compared to control subjects in AR and asthma prescriptions, including both asthma controller and reliever prescriptions. Additionally, the AIT group had significantly greater likelihood of stepping down asthma treatment (P <0·0001). In addition to the reduction in asthma treatment in the AIT group, a greater reduction in severe asthma exacerbations was demonstrated (P<0·05). Reductions in pneumonia with antibiotic prescriptions, hospitalisations, and duration of inpatients stays were all in favour of AIT.

Interpretation

The study extends the existing RCT evidence for AIT by demonstrating longer-term and sustained effectiveness of AIT in the real world. Additionally, in patients with concurrent asthma, AIT was associated with reduced likelihood of asthma exacerbations and pneumonia.

Funding

The study was funded by ALK A/S.

Subcutaneous immunotherapy takes more than the time in the clinic

OBJECTIVE

The aim of this study was to investigate the time use and both direct and indirect costs associated with subcutaneous immunotherapy (SCIT) for adults with allergic rhinitis (AR) and caregivers of children with AR in the US.

METHODS

We conducted a survey to assess the retrospective time use and direct costs of SCIT. The populations surveyed included adults and caregivers of children (aged 5-17) with symptomatic AR of moderate or higher severity who are currently receiving or have previously started allergy immunotherapy (AIT). The retrospectively collected, self-reported time consumption and direct costs per clinic visit when receiving SCIT were assessed as well as the productivity loss associated with SCIT. Data were analyzed using univariate descriptive statistics.

RESULTS

The study included 106 adults with AR and 191 caregivers of children with AR. We found that the median time spent per visit to the clinic was 50 min for both groups, including travel time and time at the clinic. The direct costs related to each visit included parking fees, road tolls and other costs. Adults spent $10 on parking, $9 on tolls and $10 on other costs. Finally, a median of 4 h of work was missed for both the adult patients and the adults accompanying a child.

CONCLUSIONS

We found that SCIT is associated with substantial direct patient costs and productivity loss for both adults with AR and caregivers of children with AR.

Reduced anaphylactic potential of denatured pullulan-conjugated Cry j 1

Japanese Cedar (JC) pollinosis is the most common seasonal allergic rhinitis in Japan. Throughout the JC pollen season, patients suffer from the allergic symptoms, resulting in a reduction of quality of life. Allergy immunotherapy (AIT) is an established treatment option for a wide range of allergens that unlike symptomatic treatments (e.g. antihistamines) may provide sustained immune tolerance. However, AIT, especially subcutaneous immunotherapy (SCIT) has a fatal anaphylaxis risk due to the use of crude allergen extracts. Consequently, development of allergen derivatives with substantially reduced anaphylactic potential is desirable. An allergen derivative that showed reduced IgE-binding and anaphylactic potential was developed through conjugation of native Cry j 1 (n Cry j 1), a major JC allergen, to the polysaccharide pullulan followed by chemical but non-covalent denaturation. The resulting Cry j 1 allergen derivative, Dn p-Cry j 1, showed reduced IgE-binding and IgE-mediated effector cell activation in vitro using an ELISA competition assay and a mast cell activation model (EXiLE). Reduced anaphylactic potential of Dn p-Cry j 1 in vivo was demonstrated using the rat passive cutaneous anaphylaxis (PCA) assay. The difference in anaphylactic potential of Dn p-Cry j 1 compared to n Cry j 1 in wild-type rats was of the same magnitude as the difference seen in the anaphylaxis reactions obtained with n Cry j 1 in wild-type rats and mast-cell deficient rats, indicating a dramatic reduction in anaphylactic potential of Dn p-Cry j 1. These results indicate that Dn p-Cry j 1 is a promising candidate for next-generation JC AIT.

Disease-Modifying Effect of Japanese Cedar Pollen Sublingual Immunotherapy Tablets

BACKGROUND

Japanese cedar (JC) pollinosis is a common allergic rhinitis in Japan. JC pollen sublingual immunotherapy (SLIT) tablets are licensed for the treatment of JC pollinosis.

OBJECTIVE

To assess the disease-modifying effects of JC pollen SLIT tablets over 5 years (2014-2019), comprising a 3-year treatment period and 2-year follow-up.

METHODS

A total of 1042 patients with JC pollinosis (aged 5-64 years) were included in the study. An optimal dose-finding study was performed in the first 15 months, after which 240 patients in the placebo (P) group and 236 patients in the optimal active dose (A) group (5000 Japanese allergy units) were re-randomized to receive P or A for an additional 18 months (designated AA, AP, PA, and PP groups). Clinical efficacy was evaluated by the total nasal symptom and medication score (TNSMS) during the peak symptom period of each JC pollen season over 3 years of treatment and 2 years of observation after treatment cessation.

RESULTS

The AA, AP, and PA groups exhibited significantly reduced TNSMS; however, the largest relative reduction was seen in the AA group both during the treatment period (third season, 46.3% vs PP, P < .001) and during the 2-year follow-up period (fourth and fifth seasons, 45.3% and 34.0% vs PP, respectively; P < .001). The most common adverse drug reactions were mild reactions at the administration site.

CONCLUSIONS

JC pollen SLIT tablets show sustained clinical efficacy during 3 years of treatment and sustained disease-modifying effects for at least 2 years after treatment cessation.

Sublingual immunotherapy tablet: a cost-minimizing alternative in the treatment of tree pollen-induced seasonal allergic rhinitis in Canada

BACKGROUND

A cost-minimization analysis (CMA) was performed to evaluate the economic implications of introducing the SQ Tree sublingual immunotherapy (SLIT)-tablets marketed as ITULATEK® (Health Canada regulatory approval in April 2020) for the treatment of pollen-induced (birch, alder and/or hazel) seasonal allergic rhinitis in Canada (Ontario and Quebec), where Tree Pollen subcutaneous immunotherapy (SCIT) is already an available treatment option.

METHODS

A CMA was deemed appropriate and was based on the assumption that the SQ Tree SLIT-tablets have comparable efficacy to Tree Pollen SCIT. A societal perspective was adopted in the model, including relevant costs of medications, costs of health care services, and productivity losses. The time horizon in the model was three years, which corresponds to a minimal treatment course of allergy immunotherapy. Resource use and costs were based on published sources, where available, and validated by Canadian specialist clinicians (allergists) in active practice in Ontario and in Quebec, where applicable. A discount rate of 1.5% was applied in accordance with the Canadian Agency for Drugs and Technologies in Health (CADTH) guidelines. To assess the robustness of the results, scenario analyses were performed by testing alternative assumptions for selected parameters (e.g., Tree Pollen SCIT resource use, discount rates, number of injections, annual SCIT dosing with maintenance injections, and nurse time support), to evaluate their impact on the results of the analysis.

RESULTS

The direct costs, including the drug costs, and physician services costs, for three years of treatment, were similar for both SQ Tree SLIT-tablets vs. Tree Pollen SCIT in both Ontario and Quebec ($2799.01 and $2838.70 vs. $2233.76 and $2266.05 respectively). However, when the indirect costs (including patient's travel expenses and lost working hours) are included in the model, total savings for the treatment with SQ Tree SLIT-tablets of $1111.79 for Ontario and $1199.87 for Quebec were observed. Scenario analyses were conducted and showed that changes in assumptions continue to result in the savings of SQ Tree SLIT- tablets over Tree Pollen SCIT.

CONCLUSIONS

The CMA indicates that SQ Tree SLIT-tablets are a cost-minimizing alternative to Tree Pollen SCIT when considered from a societal perspective in Ontario and Quebec.

Real-world evidence costs of allergic rhinitis and allergy immunotherapy in the commercially insured United States population

OBJECTIVE

To assess total and allergic rhinitis (AR)-related healthcare costs among AR patients residing in the United States with a focus on patients persisting with AIT.

METHODS

AR patients were identified in the IBM MarketScan database between 1 January 2014 to 31 March 2017. Patients receiving allergy immunotherapy (AIT) were identified with relevant billing codes (earliest AIT claim = index date); non-AIT patients were identified with claims containing a diagnosis code for AR (earliest AR claim = index date). AIT patients reaching 25+ injection claims were analyzed as a separate maintenance cohort. All patients were required to have continuous enrollment for 12 months preceding and following index.

RESULTS

A total of 2,334,530 AR patients were included; 103,207 had at least 1 AIT claim, with 45,279 (43.9%) of these patients reaching maintenance, and 24,640 AIT patients (23.9%) never presenting a single injection claim. Compared to non-AIT patients, patients initiating AIT presented higher rates of baseline comorbidities, including asthma (30.1% vs. 7.5%) and conjunctivitis (21.7% vs. 4.4%). During the follow-up period, patients reaching the maintenance phase of AIT incurred lower total costs than the overall AIT cohort ($10,431±$16,606 vs. $11,612±$24,797), and also presented lower follow-up hospitalization costs ($698±$7,248 vs. $1,281±$12,991) and total medical costs ($7950±$13,844 vs. $8989±$22,019).

CONCLUSIONS

Continued efforts are needed to increase patient awareness of available options and adherence to AIT, along with reducing wastage. Despite AIT patients presenting fairly progressed disease at the time of treatment initiation, this therapy remains an economical treatment option, as it was not accompanied by substantial increases in overall healthcare expenditure, and may promote positive societal impacts beyond the direct medical costs.What is known on this topicThe prevalence of allergic diseases has increased over the past 50 years and affects between 10-30% of the world population.Allergic rhinitis (AR) poses a significant economic burden in the form of both direct and indirect costsAllergy immunotherapy (AIT) is the only treatment option able to modify the underlying course of the disease.What this study addsSpecific all-cause and AR-related healthcare costs decreased following the initiation of AIT among patients diagnosed with AR, with the largest decreases observed among AIT patients reaching the maintenance phase of treatment, while non-AIT patients showed increases in all categories assessed over a similar follow-up period.Cost decreases among AIT patients were observed despite increased levels of comorbidities compared to non-AIT patients, as the AIT cohort presented elevated rates of atopic dermatitis (7.1% vs. 2.7%), conjunctivitis (21.7% vs. 4.4%), asthma (30.1% vs. 7.5%), and chronic sinusitis (22.6% vs. 4.9%).An analysis of patients' index subcutaneous AIT consultation revealed substantial variability in the initial treatment costs, with nearly 20% of paid amounts exceeding $1,000; given nearly 1 in 4 AIT patients who get AIT mixed never came back for their first injection, this highlights an opportunity to target frontloaded billing practices and the timing of mixing/injection as an area to minimize healthcare waste.

A Real-Life One-Year Non-Interventional Study Assessing Safety, Tolerability, and Treatment Outcome of the SQ HDM SLIT-Tablet (Acarizax®) in House Dust Mite Allergic Rhinitis With or Without Asthma

Introduction

The aim of this study was to investigate the safety profile, tolerability, and outcome of the SQ^® house dust mite (HDM) sublingual immunotherapy (SLIT)-tablet after 1 year of treatment in clinical practice among adults with HDM-related allergic rhinitis (AR) ± allergic asthma (AA).

Methods

In a non-interventional multicenter, observational study, patients were followed at 3 visits for 1 year. Adverse events (AE) were recorded at all visits. Patients graded their allergic symptoms as none, mild, moderate, or severe, and recorded AR and AA medication use. Asthma symptom control was assessed according to the Global Initiative for Asthma (GINA).

Results

One hundred and ninety-eight patients were included; 115 (58%) had AR without asthma and 83 (42%) had both AR and AA. One hundred and sixty-six (84%) patients completed the study. Eighty percent of patients experienced an AE: 151 (75%) AEs were mild, 42 (21%) moderate, and 4 (2%) severe. Three patients (1.5%) reported four events that were considered serious (SAEs). One SAE was considered possibly treatment-related. No anaphylactic reactions occurred. The proportion of patients experiencing allergy symptom reductions by at least one step were 75% (nasal), 62% (eye), 16% (skin), and 13% (other symptoms); 75% of patients with AA experienced a decrease of at least one step in bronchial symptoms. AR medication and inhaled corticosteroids were statistically significant reduced.

Conclusion

The SQ HDM SLIT-tablet was safe and well tolerated; the type, frequency, and severity of AEs resembled what RCTs have previously demonstrated. As explorative endpoints, statistically significant reductions in AR and AA symptoms and medication use were seen along with improved asthma control after 1 year of treatment, implying that clinically meaningful changes were seen after 1 year of treatment with the SQ HDM SLIT-tablet.

Supplementary Information

The online version contains supplementary material available at 10.1007/s41030-021-00150-z.

Biologics and Allergy Immunotherapy in the Treatment of Allergic Diseases

Allergic diseases represent some of the most chronic and costly chronic conditions. Medical management may require long-term pharmacotherapy, which is often associated with poor adherence. Although medications provide symptomatic control, they do not modify the allergic disease. Patients may prefer disease-modifying treatments that provide lasting benefits after discontinuation. To date, allergy immunotherapy is the only proved disease modification therapy associated with lasting benefits after discontinuation. However, allergy immunotherapy safety and efficacy has only been established in allergic rhinitis, mild to moderate asthma, and some patients with atopic dermatitis.

Clinical Practice of Allergen Immunotherapy for Allergic Rhinoconjunctivitis and Asthma: An Expert Panel Report

Allergen immunotherapy (AIT) reduces symptoms and medication use associated with allergic rhinitis with or without conjunctivitis and allergic asthma. Although several AIT guidelines exist, there remain unanswered questions about AIT that are relevant to everyday practice. Our objective was to prepare an evidence-based overview addressing the practical aspects of AIT in clinical practice based on published evidence and the experience of international experts in the field. Topics covered include interpretation and translation of clinical trial data into everyday clinical practice (eg, allergen doses and treatment duration), assessment of risk and treatment of local and systemic allergic reactions, recommendations for improvement of AIT guidelines, and identification of appropriate data for seeking regulatory approval, to name a few. Many informational gaps in AIT practice need further evaluation as products and practices evolve.

Health and Economic Outcomes of Home Maintenance Allergen Immunotherapy in Select Patients with High Health Literacy during the COVID-19 Pandemic: A Cost-Effectiveness Analysis During Exceptional Times

BACKGROUND

Allergen immunotherapy (AIT) is safe and effective but is typically administered under strict clinic observation to mitigate the risk of a systemic reaction to immunotherapy (SRIT). However, in the setting of the global coronavirus disease 2019 pandemic, alternative care models should be explored.

OBJECTIVE

To evaluate the cost-effectiveness of home immunotherapy self-administration (HITSA) in a highly idealized circumstance for provision of maintenance AIT in a shelter-in-place or other scenarios of unforeseen reduction in nonessential medical services.

METHODS

Markov modeling was used to compare in-office clinic AIT in selected patients using cohort analysis and microsimulation from the societal and health care perspectives.

RESULTS

Assuming similar SRIT rates, HITSA was found to be a cost-effective option with an incremental cost-effectiveness ratio of $44,554/quality-adjusted life-year when considering both incremental epinephrine autoinjector costs and coronavirus disease 2019 risks. Excluding epinephrine autoinjector costs, HISTA dominated other options. However, outside of pandemic considerations, HITSA was not cost-effective (incremental cost-effectiveness ratio, $198,877,286) at annual epinephrine autoinjector costs above $287. As the incremental HITSA SRIT rate increased above 15%, clinic AIT was the most cost-effective strategy. Excluding both pandemic risks and risk of motor vehicle accident fatality from round-trip clinic transit, clinic AIT dominated other strategies. Clinic AIT was the more cost-effective option at very high fatality relative risk for HITSA or at very low annual risk of contracting coronavirus disease 2019.

CONCLUSIONS

Under idealized assumptions HITSA can be a safe and cost-effective option during a global pandemic in appropriately selected patients provided home rates of SRIT remain stable.

COVID-19: Pandemic Contingency Planning for the Allergy and Immunology Clinic

In the event of a global infectious pandemic, drastic measures may be needed that limit or require adjustment of ambulatory allergy services. However, no rationale for how to prioritize service shut down and patient care exists. A consensus-based ad-hoc expert panel of allergy/immunology specialists from the United States and Canada developed a service and patient prioritization schematic to temporarily triage allergy/immunology services. Recommendations and feedback were developed iteratively, using an adapted modified Delphi methodology to achieve consensus. During the ongoing pandemic while social distancing is being encouraged, most allergy/immunology care could be postponed/delayed or handled through virtual care. With the exception of many patients with primary immunodeficiency, patients on venom immunotherapy, and patients with asthma of a certain severity, there is limited need for face-to-face visits under such conditions. These suggestions are intended to help provide a logical approach to quickly adjust service to mitigate risk to both medical staff and patients. Importantly, individual community circumstances may be unique and require contextual consideration. The decision to enact any of these measures rests with the judgment of each clinician and individual health care system. Pandemics are unanticipated, and enforced social distancing/quarantining is highly unusual. This expert panel consensus document offers a prioritization rational to help guide decision making when such situations arise and an allergist/immunologist is forced to reduce services or makes the decision on his or her own to do so.

A quality-of-life mapping function developed from a grass pollen sublingual immunotherapy trial to a tree pollen sublingual immunotherapy trial

Aims: Allergic rhinitis is caused by sensitivity to environmental allergens that can significantly impact quality-of-life. The objective of this analysis was to estimate health state utilities and quality-adjusted life days (QALDs) for a tree allergy immunotherapy trial, TT-04 (EudraCT No.2015-004821-15). Health-state utilities are a measure of patient preference for health states and are necessary to derive QALDs for cost-utility analysis. Preference-based utilities were not collected in the TT-04 trial, so a mapping algorithm was developed based on a similar grass allergy immunotherapy trial, GT-08 (EudraCT No. 2004-000083-27), to estimate utilities.Methods: A two-part model was developed to predict utilities for the GT-08 trial and applied to the TT-04 trial to estimate the difference in mean utility and QALDs between SQ tree sublingual immunotherapy (SLIT)-tablet and placebo.Results: Mean utility difference between SQ tree SLIT-tablet and placebo was 0.030 [95% CI = 0.015-0.046] during the birch pollen season (BPS), 0.019 [95% CI = 0.007-0.030] during the tree pollen season (TPS) and 0.018 [95% CI = 0.007-0.030] during the full trial. The treatment showed a QALD benefit of 1.26 [95% CI = 0.619-1.917] during the BPS, 1.90 [95% CI = 0.692-3.047] during the TPS, and 2.47 [95% CI = 0.930-4.101] during the full trial.Limitations: The generalizability of this algorithm is limited to allergy trials containing the same covariates as those present in the model. The analysis also assumes that grass and tree pollen allergy have the same relationship with EQ5D utilities, which is supported by the fact that both grass and tree pollen induce similar symptoms.Conclusions: Application of the mapping function enabled the calculation of QALDs associated with the treatment, with the caveat that data were extrapolated from grass seasonal allergy to tree seasonal allergy. The results showed a significant QALD benefit of the treatment over placebo in treatment of tree pollen-induced rhinoconjunctivitis.

Allergen Immunotherapy and Atopic Dermatitis: the Good, the Bad, and the Unknown

PURPOSE OF REVIEW

In light of the recent advancements in atopic dermatitis treatment, this review aims to summarize the utility and efficacy of allergy immunotherapy in atopic dermatitis patients. We examine its mechanism, pathophysiology, cost-efficacy, and current guidelines for clinical practice.

RECENT FINDINGS

The literature supports the use of allergy immunotherapy in atopic conditions such as allergic rhinitis and asthma but insufficient evidence exists to suggest its efficacy in atopic dermatitis. The use of allergy immunotherapy has been shown to provide long-term cost savings in both the USA and the European Union in certain populations but differences in prescribing patterns and manufacturing make it difficult to study its impact on a larger, generalizable scale. Conflicting meta-analyses data and conclusions highlight the need for better, higher quality research to better understand allergy immunotherapy utility in atopic dermatitis.

Efficacy and Safety of HDM SLIT Tablet in Japanese Adults with Allergic Asthma

BACKGROUND

The standardized quality (SQ) house dust mite (HDM) sublingual immunotherapy (SLIT) tablet has demonstrated efficacy and safety for allergic asthma (AA) in European trials.

OBJECTIVE

To evaluate the efficacy and safety of SQ HDM SLIT tablet treatment for up to 19 months in Japanese adults with AA.

METHODS

In this randomized, double-blind, placebo-controlled trial, patients aged 18 to 64 years with AA were randomly assigned (1:1:1) to SQ HDM SLIT doses of 10,000 or 20,000 Japanese Allergy Unit or placebo. Subjects had Asthma Control Questionnaire score of 1.0 to 1.5 and daily inhaled corticosteroid use of 200 to 400 μg of fluticasone propionate at randomization. The primary end point was the time from randomization to the first asthma exacerbation as the inhaled corticosteroid dose was being reduced.

RESULTS

Of the 826 randomized subjects, 693 (84%) completed the trial. No statistically significant differences between the active groups and the placebo group were observed for the primary or any other efficacy end points. However, post hoc analysis indicated a significant difference between the 20,000 Japanese Allergy Unit and placebo groups among subjects who used a short-acting β₂-agonist during the baseline period (hazard ratio, 0.70; 95% CI, 0.48-1.00; P = .04997). No deaths or anaphylactic reactions were reported. Most adverse events were mild to moderate in severity.

CONCLUSIONS

The trial demonstrated a favorable safety profile of the SQ HDM SLIT tablet in Japanese adult patients with AA. The treatment appeared to be efficacious in patients requiring rescue medication (ie, short-acting β₂-agonist) at baseline in the efficacy assessment using asthma exacerbation during inhaled corticosteroid reduction (JapicCTI number 121847).

Coadministration of Sublingual Immunotherapy Tablets and Management of Potential Adverse Effects: Austrian, German, and Swiss Expert Recommendations

Sublingual immunotherapy (SLIT) is currently available as liquid drops and tablets for treatment of allergic patients. Because several allergens are available and many patients are polyallergic, it is possible to treat patients with multiple clinically relevant allergies by >1 SLIT product. Austrian, German, and Swiss medical experts discussed the available data on allergen uptake at the oral mucosa and recently published data on coadministration of a grass and a ragweed tablet. The experts agreed on a schedule considering data from a North American trial on sequential administration of 2 SLIT-tablets with different allergens and their own experiences made during initiation of treatment with >1 SLIT-tablet in their clinics and subsequent self-administration by the patient and discussed the handling and management of potential adverse drug reactions (ADRs). According to the medical experts' opinion, tolerability at each phase of administration and patient preference should be taken into consideration to ensure a high level of adherence to treatment. Local ADRs that are uncomfortable for the patient may be alleviated by a 2- to 4-week course of antihistamine pretreatment. ADRs with severe swelling and/or systemic ADRs need the physician's particular attention and a decision together with the patient on continuation of treatment with SLIT or possible alternative routes of administration.

Establishment of enzyme-linked immunosorbent facilitated antigen binding as a biomarker assay for Japanese cedar pollen allergy immunotherapy

BACKGROUND

Clinical efficacy of allergen-specific Immunotherapy (AIT) towards Japanese cedar (JC) pollen allergy is firmly established but JC pollen-specific biomarker assays are lacking. Treatment-related increase of allergen-specific antibodies is a robust biomarker of successful AIT. Allergen-specific non-IgE antibodies are believed to reduce the effects of allergen exposure by competing with IgE for allergen binding, and in-vitro assays quantifying the effects of AIT-induced IgE-blocking antibodies are advantageous. A cell-free enzyme-linked immunosorbent facilitated antigen binding (ELIFAB) assay of JC pollen was established.

METHODS

Serum IgE-allergen complexes were captured by immobilized recombinant CD23, and allergen-IgE-CD23 complexes were detected by a biotin-conjugated anti-human IgE antibody. Sera from JC pollen-allergic subjects without or with subcutaneous immunotherapy (SCIT) with JC pollen extract were used (n = 11/group).

RESULTS

Optimal assay conditions were established at 20 μg/mL CD23 and 0.3 μg/mL JC pollen extract, and the dependency on CD23 and IgE was verified. The data show that the JC pollen ELIFAB assay is fit for purpose and demonstrates that the IgE-blocking activity is significantly increased in the JC pollen SCIT group compared with the non-treated group.

CONCLUSION

The JC pollen ELIFAB assay represents a simple, cell-free biomarker assay for monitoring the development of IgE-blocking antibody activity during JC pollen AIT.

Sublingual immunotherapy tablet for the treatment of house dust mite allergic rhinitis in Canada: an alternative to minimize treatment costs?

BACKGROUND

A cost-minimization analysis (CMA) was performed to estimate the economic impact of introducing the SQ house dust mite sublingual immunotherapy (SQ HDM SLIT)-tablet marketed as ACARIZAX™ (regulatory approval May 2017) for the treatment of HDM-induced allergic rhinitis in Canada (Ontario and Quebec), where house dust mite subcutaneous immunotherapy (HDM SCIT) is already an available treatment option.

METHODS

A CMA was deemed appropriate and was based on the assumption that the SQ HDM SLIT-tablet has comparable efficacy to HDM SCIT. A societal perspective was adopted in the model, including relevant costs of medications, health care services and productivity loss. A 3 year time horizon was used corresponding to a recommended treatment course of allergy immunotherapy. Resource use and costs were based on published sources, where possible, and validated and complemented by a Canadian specialist clinician (allergist) in active practice in Ontario and in Quebec, respectively, where applicable. A discount rate of 1.5% was applied in accordance with the Canadian Agency for Drugs and Technologies in Health (CADTH) guidelines. To assess the robustness of the results, sensitivity analyses were performed by testing alternative assumptions for selected parameters, to understand their impact on the results of the analysis.

RESULTS

The direct treatment costs for a 3-year treatment with SQ HDM SLIT-tablets were higher than for HDM SCIT for both provinces, Ontario and Quebec ($4732.12 and $4829.03 vs. $3434.51 and $2987.74). However, when adding the indirect costs to the model, total savings for the treatment with SQ HDM SLIT-tablets of $1833.00 for Ontario and $769.03 for Quebec were observed. Sensitivity analyses with varying HDM SCIT resource use, discount rates, titration and maintenance injections, nurse time, and number of injections per vial resulted in savings of SQ HDM SLIT-tablets over HDM SCIT in all scenarios analysed.

CONCLUSIONS

The CMA indicates that SQ HDM SLIT-tablets are a cost-minimizing alternative to HDM SCIT when considered from a societal perspective in Ontario and Quebec.

Two grass pollen tablets commercially available for allergy immunotherapy display different IgE epitope repertoires

Background

The distribution of Pooideae species varies across Europe. Especially, Timothy is less represented in Southern than in Northern Europe. Since allergenic cross-reactivity between pollens from different grasses is only partial, grass pollen-allergic patients are expected to display different sensitization profiles, with specific IgE directed against different combinations of allergenic epitopes, depending on their living places in Europe and the grasses they are exposed to. In this context, this study aimed at comparing two tablets commercially available for allergy immunotherapy, namely a 5-grass (Cocksfoot, Meadow-grass, Rye-grass, Sweet vernal-grass and Timothy) and a 1-grass (Timothy) pollen tablets, for their ability to represent the sensitization profiles of patients, depending on whether they live in Southern or Northern Europe.

Methods

Sera were collected from adult patients living in Spain (n = 19) and Sweden (n = 22). Tablets were compared for their ability to inhibit the binding of patient serum IgE to pollen allergens from twelve grasses commonly distributed throughout Europe, as determined by the areas under the curves obtained by ELISA-inhibition. Tablets were adjusted to an equivalent allergenic activity, based on the CBER/FDA bioequivalent allergy unit.

Results

Inhibition of the IgE binding to pollen allergens from twelve grasses was significantly stronger with the 5-grass than with the 1-grass pollen tablet (p < 0.0001), regardless of whether patients were considered as a whole or by geographical area. This difference between tablets was significantly greater for Southern than Northern European patients (p < 0.05).

Conclusions

Compared to the 1-grass tablet, the 5-grass tablet generally covers better the sensitization profiles of European patients, especially patients from Southern Europe, in principle less exposed to pollen from Timothy than from other grasses. The 5-grass tablet is therefore expected to elicit larger spectra of blocking antibodies, which might have implications in light of the generally accepted mechanisms of allergy immunotherapy.

Electronic supplementary material

The online version of this article (10.1186/s13601-019-0253-z) contains supplementary material, which is available to authorized users.

Safety profile of the SQ house dust mite sublingual immunotherapy-tablet in Japanese adult patients with house dust mite-induced allergic asthma: a randomized, double-blind, placebo-controlled phase I study

Objective: The SQ house dust mite (HDM) sublingual immunotherapy (SLIT)-tablet has demonstrated effective treatment of HDM-induced allergic asthma in patients 18 years or older in European trials. This study investigated its safety and immunology profile in Japanese adult patients with mild-to-moderate HDM-induced allergic asthma. Methods: In this randomized, double-blind, placebo-controlled study, 48 Japanese patients were randomly assigned to a daily treatment of SQ HDM SLIT-tablet or placebo (3:1) for 14 d with or without an up-dosing regimen. Active groups comprised 5000, 10,000 or 20,000 Japanese Allergy Unit (JAU) for 14 d, and the up-dosing group comprised 5,000 JAU in day 1-3, 10,000 JAU in day 4-7 and 20,000 JAU in day 8-14. Results: No marked differences were observed in the incidence rate of adverse events (AEs) and their severity among active groups. The five most common investigational medicinal product (IMP)-related AEs were local events at the application site observed within 30 min after the intake of the SQ HDM SLIT-tablet. Although most events recovered within 1 h, mouth edema indicated a different profile of duration with more than 25% of the events lasting for more than 1 h. Conclusions: The SQ HDM SLIT-tablet of up to 20,000 JAU was well tolerated, and safety profile was acceptable for Japanese subjects with HDM-induced allergic asthma.

Peanut allergens

Peanut allergens have the potential to negatively impact on the health and quality of life of millions of consumers worldwide. The seeds of the peanut plant Arachis hypogaea contain an array of allergens that are able to induce the production of specific IgE antibodies in predisposed individuals. A lot of effort has been focused on obtaining the sequences and structures of these allergens due to the high health risk they represent. At present, 16 proteins present in peanuts are officially recognized as allergens. Research has also focused on their in-depth immunological characterization as well as on the design of modified hypoallergenic derivatives for potential use in clinical studies and the formulation of strategies for immunotherapy. Detailed research protocols are available for the purification of natural allergens as well as their recombinant production in bacterial, yeast, insect, and algal cells. Purified allergen molecules are now routinely used in diagnostic multiplex protein arrays for the detection of the presence of allergen-specific IgE. This review gives an overview on the wealth of knowledge that is available on individual peanut allergens.

Intra-Seasonal Initiation of the SQ-Standardised Grass Allergy Immunotherapy Tablet Routinely Applied by Allergy Specialists and General Practitioners with Experience in Treatment of Allergy: A Non-Interventional Observational Study

INTRODUCTION

Intra-seasonal start of treatment with the SQ® grass sublingual immunotherapy (SLIT) tablet (GRAZAX®, ALK, Denmark) has been previously demonstrated to be well-tolerated. The objective of our study was to investigate the tolerability of intra-seasonal start of treatment comparing patients treated by allergists and general practitioners experienced in treatment of allergy (GPs).

METHODS

In a non-interventional, open-label, observational study, data on intra-seasonal start with the SQ® grass SLIT tablet were recorded in patients treated by allergists and GPs in Germany. Adverse events (AEs) were recorded by the physicians at first administration and during the 1-3-month observation period. The tablets taken and any AEs were recorded by the patients in diaries for the first 14 days.

RESULTS

Treatment with the SQ® grass SLIT tablet was started in 198 patients, and in 179 intra-seasonal (allergists: 140, GPs: 39) and 19 post-seasonal; average treatment period was 47 days. AEs related to intra-seasonal start were reported in 43.6% of patients; no relevant differences between allergists and GPs were observed. In the subgroup of GPs, patients were younger (p = 0.0191), had more frequently asthma (p = 0.0043), more patients used symptomatic medication in the previous pollen season (p = 0.0198) and were more frequently treated for other diseases (p = 0.0467). In the allergists subgroup, more diagnostic allergy tests were applied (p < 0.0001) with less anti-allergic premedication at first administration (p = 0.0026).

CONCLUSION

The intra-seasonal start of treatment with the SQ® grass SLIT tablet in patients routinely treated by allergists or GPs with experience in treatment of allergy was well-tolerated, although patient characteristics were different with respect to age, frequency of asthma and concomitant allergies, use of symptomatic medication in the previous grass pollen season and concomitant treatment of other diseases. The safety profile from a previous placebo-controlled clinical trial and data from a previous real-life study on intra-seasonal start performed by allergists were confirmed.

Immunotherapy: Treating with Fewer Allergens?

Polysensitization, sensitization to more than one allergen, is a common feature of patients with allergic rhinitis, and may be a risk factor for subsequent development of allergic diseases, especially allergic asthma. However, a polysensitized patient does not necessarily have polyallergy, a documented, causal relationship between exposure to 2 or more specific, sensitizing allergens and the subsequent occurrence of relevant clinical symptoms of allergy. Allergen immunotherapy treatment strategy for the polysensitized patient in Europe is to treat the single or 2 most clinically relevant allergen(s), whereas patients in the United States are usually treated for all potential clinically relevant allergens.

The SQ House Dust Mite SLIT-Tablet Is Well Tolerated in Patients with House Dust Mite Respiratory Allergic Disease

BACKGROUND

The SQ house dust mite (HDM) SLIT-tablet (ALK, Denmark) addresses the underlying cause of HDM respiratory allergic disease, and a clinical effect has been demonstrated for both HDM allergic rhinitis and allergic asthma. Here, we present pooled safety data from an adult population with HDM respiratory allergy, with particular focus on the impact of asthma on the SQ HDM SLIT-tablet tolerability profile.

METHODS

Safety data from 2 randomised double-blind, placebo-controlled clinical trials were included: MT-04: 834 adults with HDM allergic asthma not well controlled by inhaled corticosteroids and with HDM allergic rhinitis, and MT-06: 992 adults with moderate-to-severe HDM allergic rhinitis despite the use of allergy pharmacotherapy and with or without asthma.

RESULTS

The proportion of subjects experiencing adverse events (AEs) was greater in the active treatment group (12 SQ-HDM; 73% of subjects) compared to placebo (53%). The most common treatment-related AEs were local allergic reactions. No AEs were reported as systemic allergic reactions. Regardless of asthma status, most AEs were mild or moderate (>97% of AEs) and the frequency of serious AEs was low. Subgroup analysis revealed no statistically significant difference in the risk of experiencing moderate or severe treatment-related AEs for subjects with asthma compared to subjects without asthma (p = 0.88). In addition, subjects with partly controlled or uncontrolled asthma were no more likely to experience moderate or severe treatment-related AEs than subjects with controlled asthma (p = 0.42).

CONCLUSION

The SQ HDM SLIT-tablet is well tolerated, and the safety profile was comparable for subjects with HDM respiratory allergic disease irrespective of asthma status.

Utility and Comparative Efficacy of Recombinant Allergens Versus Allergen Extract

Allergy immunotherapy (AIT) is the only disease-modifying therapy for the treatment of allergic diseases. Although its efficacy and utility are well-established, the potential for serious adverse events, cumbersome and lengthy treatment protocols, and variability of natural allergen preparations have limited its widespread application. Recent advances in recombinant technology have opened new avenues for the development of AIT vaccines. The purpose of this review is to highlight recent evidence on the use of novel recombinant vaccines and review the mechanisms, efficacy, safety, and limitations of AIT. Emerging evidence suggests that recombinant vaccines may provide a viable treatment alternative that improves on the limitations of natural extract therapy while maintaining efficacy.

Safety Review of 5-Grass Pollen Tablet from Pooled Data of Clinical Trials

BACKGROUND

The 5-grass pollen sublingual tablet has been approved for the treatment of grass pollen-induced allergic rhinoconjunctivitis in subjects with or without intermittent asthma.

OBJECTIVE

To provide a comprehensive analysis of the safety profile of the 5-grass tablet on the basis of pooled data from 8 clinical trials.

METHODS

Subjects (5-65 years old) with medically confirmed grass pollen-induced allergic rhinoconjunctivitis were included in the double-blind studies. Those with intermittent asthma not requiring treatment other than inhaled beta-2 agonists could participate. Randomized subjects received a 5-grass or placebo tablet daily 2 or 4 months preseasonally and coseasonally (5 single-season studies, over 3 years in a long-term study) or outside the season (phase I studies). Adverse events were pooled and analyzed descriptively.

RESULTS

Among 2,512 subjects enrolled, 1,514 received the 5-grass tablet. A total of 1,038 adults and 154 pediatric (5-17 years old) subjects were treated with the 300 Index of Reactivity dose (vs 840 and 158 placebo recipients, respectively); 17% had intermittent asthma, and 62% were polysensitized. Adverse reactions (ADRs) reported in more than 10% of actively treated subjects were mild or moderate application-site reactions, for example, oral pruritus 25% (placebo 4%) and throat irritation 21% (placebo 3%). These generally occurred during the first week of treatment and decreased over time. They led to discontinuation in less than 2.5% of subjects. None of the 3 serious ADRs were reports of anaphylaxis. No notable differences were detected in terms of incidence, nature, and severity of ADRs between adult and pediatric populations, nor between subjects with or without asthma.

CONCLUSIONS

The pooled analysis in 1,514 subjects from 8 clinical studies demonstrates that the 5-grass pollen sublingual tablet has a similar good safety profile in adult and pediatric patients with or without mild, intermittent asthma.

Results from the 5-year SQ grass sublingual immunotherapy tablet asthma prevention (GAP) trial in children with grass pollen allergy

BACKGROUND

Allergy immunotherapy targets the immunological cause of allergic rhinoconjunctivitis and allergic asthma and has the potential to alter the natural course of allergic disease.

OBJECTIVE

The primary objective was to investigate the effect of the SQ grass sublingual immunotherapy tablet compared with placebo on the risk of developing asthma.

METHODS

A total of 812 children (5-12 years), with a clinically relevant history of grass pollen allergic rhinoconjunctivitis and no medical history or signs of asthma, were included in the randomized, double-blind, placebo-controlled trial, comprising 3 years of treatment and 2 years of follow-up.

RESULTS

There was no difference in time to onset of asthma, defined by prespecified asthma criteria relying on documented reversible impairment of lung function (primary endpoint). Treatment with the SQ grass sublingual immunotherapy tablet significantly reduced the risk of experiencing asthma symptoms or using asthma medication at the end of trial (odds ratio = 0.66, P < .036), during the 2-year posttreatment follow-up, and during the entire 5-year trial period. Also, grass allergic rhinoconjunctivitis symptoms were 22% to 30% reduced (P < .005 for all 5 years). At the end of the trial, the use of allergic rhinoconjunctivitis pharmacotherapy was significantly less (27% relative difference to placebo, P < .001). Total IgE, grass pollen-specific IgE, and skin prick test reactivity to grass pollen were all reduced compared to placebo.

CONCLUSIONS

Treatment with the SQ grass sublingual immunotherapy tablet reduced the risk of experiencing asthma symptoms and using asthma medication, and had a positive, long-term clinical effect on rhinoconjunctivitis symptoms and medication use but did not show an effect on the time to onset of asthma.

Recombinant Allergens in Structural Biology, Diagnosis, and Immunotherapy

The years 1988-1995 witnessed the beginning of allergen cloning and the generation of recombinant allergens, which opened up new avenues for the diagnosis and research of human allergic diseases. Most crystal and solution structures of allergens have been obtained using recombinant allergens. Structural information on allergens allows insights into their evolutionary biology, illustrates clinically observed cross-reactivities, and makes the design of hypoallergenic derivatives for allergy vaccines possible. Recombinant allergens are widely used in molecule-based allergy diagnosis such as protein microarrays or suspension arrays. Recombinant technologies have been used to produce well-characterized, noncontaminated vaccine components with known biological activities including a variety of allergen derivatives with reduced IgE reactivity. Such recombinant hypoallergens as well as wild-type recombinant allergens have been used successfully in several immunotherapy trials for more than a decade to treat birch and grass pollen allergy. As a more recent application, the development of antibody repertoires directed against conformational epitopes during immunotherapy has been monitored by recombinant allergen chimeras. Although much progress has been made, the number and quality of recombinant allergens will undoubtedly increase and keep improving our knowledge in basic scientific investigations, diagnosis, and therapy of human allergic diseases.

Allergen Immunotherapy

Allergies affect a large proportion of the population. Allergies can adversely affect productivity, sleep, and quality of life and can lead to life-threatening reactions. Allergies can spread to affect multiple organ systems. Allergen immunotherapy is the only therapy that can change the natural history of allergic disease.

Patient preferences in allergy immunotherapy (AIT) in Germany - a discrete-choice-experiment

BACKGROUND

Allergic Rhinitis (AR) is a common disorder in Europe with Allergic Asthma (AA) as a frequent comorbidity. Allergy immunotherapy (AIT) is the only causal therapy of AR and AA, and can be administered as subcutaneous injections at the physician or as sublingual drops or tablets at home. The usual treatment duration is 3 years.

OBJECTIVE

This study aimed to elicit patient preferences to identify the AIT administration mode preferred by patients.

METHODS

A discrete-choice-experiment (DCE) was developed to determine how people weight different treatment options using a paper-based questionnaire from June to September 2014, including 16 study centres. Main inclusion criteria: >18 years, grass, birch and/or house dust mite AR with moderate to severe symptoms, AIT-naïve and AIT-indicated. DCE-attributes were: Administration form, number and duration of physician visits, frequency of life-threatening anaphylactic shocks, local side-effects and co-payments.

RESULTS

Two-hundred thirty-nine subjects participated, resulting in analysable 1842 choices. All attributes were significant predictors for the treatment-choice. Ranked by importance, the following first three attributes are most preferred by patients: 1(st) Number and duration of physician visits: Fewer visits with shorter duration preferred (0.658*) 2(nd) Frequency of life-threatening anaphylactic shocks: Lower risk of shocks preferred (0.285*) 3(rd) Local side-effects: Preference for rash/swelling on upper arm over itching/swelling under the tongue (0.210*) (*coefficient-size represents relative importance of the attributes)

CONCLUSION

The most important attribute is the number and duration of visits to a physician. A lower risk of life-threatening anaphylactic shocks was ranked as the second whereas co-payments and administration form play a limited role.

Intradermal grass pollen immunotherapy increases TH2 and IgE responses and worsens respiratory allergic symptoms

BACKGROUND

Repeated low-dose grass pollen intradermal allergen injection suppresses allergen-induced cutaneous late-phase responses comparably with conventional subcutaneous and sublingual immunotherapy.

OBJECTIVE

We sought to evaluate the efficacy and safety of grass pollen intradermal immunotherapy in the treatment of allergic rhinitis.

METHODS

We randomly assigned 93 adults with grass pollen-induced allergic rhinitis to receive 7 preseasonal intradermal allergen injections (containing 7 ng of Phl p 5 major allergen) or a histamine control. The primary end point was daily combined symptom-medication scores during the 2013 pollen season (area under the curve). Analysis was by intention to treat. Skin biopsy specimens were collected after intradermal allergen challenges, and late-phase responses were measured 4 and 7, 10, or 13 months after treatment.

RESULTS

There was no significant difference in the primary end point between treatment arms (active, n = 46; control, n = 47; median difference, 14; 95% CI, -172.5 to 215.1; P = .80). Among secondary end points, nasal symptoms were worse in the intradermal treatment group, as measured based on daily (median difference, 35; 95% CI, 4.0-67.5; P = .03) and visual analog scale (median difference, 53; 95% CI, -11.6 to 125.2; P = .05) scores. In a per-protocol analysis intradermal immunotherapy was further associated with worse asthma symptoms and fewer symptom-free days. Intradermal immunotherapy increased serum Phleum pratense-specific IgE levels (P = .001) compared with those in the control arm. T cells cultured from biopsy specimens of subjects undergoing intradermal immunotherapy had higher expression of the T_H2 surface marker CRTH2 (P = .04) and lower expression of the T_H1 marker CXCR3 (P = .01), respectively. Late-phase responses remained inhibited 7 months after treatment (P = .03).

CONCLUSION

Intradermal allergen immunotherapy suppressed skin late-phase responses but was not clinically effective and resulted in worsening of respiratory allergic symptoms.

Allergen immunotherapy (AIT) for the multiple-pollen sensitive patient

INTRODUCTION

The majority of allergic subjects are polysensitized. In Europe, allergy immunotherapy (AIT) in these patients is usually limited to their single clinically most troublesome allergy while in the U.S. the immunotherapy prescription usually includes all allergen extracts to which the patient has evidence of clinical sensitivity. Areas covered: This article will review the evidence supporting the U.S. practice. It will also review the major new development in the management of polysensitized patients, the introduction of component-resolved diagnosis (CRD). Expert commentary: This allows, in many cases, distinguishing in polysensitized patients between sensitization to the major allergens of several unrelated allergen extracts and to panallergens that cause broad patterns of cross-reactivity.

300 IR HDM tablet: a sublingual immunotherapy tablet for the treatment of house dust mite-associated allergic rhinitis

INTRODUCTION

The once-daily 300 index of reactivity (IR) house dust mite (HDM) tablet (Actair®; Stallergenes Greer, Antony, France/Shionogi & Co. Ltd., Osaka, Japan) is the first sublingual immunotherapy (SLIT) tablet to be approved for the treatment of HDM-induced allergic rhinitis. Areas covered: This drug profile reviews the current body of evidence on the efficacy, safety and tolerability of the 300 IR HDM tablet, its pharmacodynamics, and its role in clinical practice. Expert commentary: Data from its clinical development program demonstrate favorable efficacy and safety in adults and adolescents with HDM-induced allergic rhinitis, irrespective of mono- or polysensitization status, or the presence of comorbid mild asthma. The 300 IR HDM tablet is effective from as early as 2 months after treatment initiation, providing allergic symptom control and a reduction in the need for symptomatic medication, while improving health-related quality of life. Clinical efficacy is maintained for 1 year after treatment is stopped.

Cost utility analysis of the SQ(®) HDM SLIT-tablet in house dust mite allergic asthma patients in a German setting

BACKGROUND

Asthma affects an estimated 300 million people worldwide with the condition associated with significant healthcare utilisation costs and a large impact on patient quality of life. The SQ(®) HDM SLIT-tablet (ACARIZAX(®), Hørsholm, Denmark) is a sublingually administered allergy immunotherapy tablet for house dust mite allergic asthma and allergic rhinitis and has recently been licensed in Europe.

OBJECTIVE

To assess the cost-effectiveness of ACARIZAX plus pharmacotherapy versus placebo plus pharmacotherapy in patients with house dust mite allergic asthma that is uncontrolled by inhaled corticosteroids, in a German setting. Eligible patients should also have symptoms of mild to severe allergic rhinitis.

METHODS

A cost utility analysis was undertaken, based on the results of a European phase III randomised controlled trial, in which ACARIZAX was compared with placebo with both treatment groups also receiving pharmacotherapy in the form of inhaled corticosteroids and short-acting β2-agonists. Cost and quality-adjusted life years from the trial were extrapolated over a nine year time horizon and the incremental cost-effectiveness ratio calculated to compare treatment options.

RESULTS

ACARIZAX plus pharmacotherapy was estimated to generate 6.16 quality-adjusted life years per patient at a cost of €5658, compared with 5.50 quality-adjusted life years (QALYs) at a cost of €2985 for placebo plus pharmacotherapy. This equated to an incremental cost of €2673, incremental QALYs of 0.66 and an incremental cost-effectiveness ratio (ICER) of €4041. The ICER was, therefore, substantially lower than the €40,000 willingness-to-pay threshold per QALY adopted for the analysis. Deterministic sensitivity analyses indicate the results are most sensitive to the utility score of ACARIZAX patients during years 2 and 3 of treatment.

CONCLUSION

This analysis indicates that ACARIZAX plus pharmacotherapy is cost-effective compared with placebo plus pharmacotherapy for house dust mite allergic asthma patients in Germany. If a disease-modifying effect can be proven the results of this analysis may underestimate the true benefits of ACARIZAX.

Cost-minimization analysis of sublingual immunotherapy versus subcutaneous immunotherapy for house dust mite respiratory allergic disease in Denmark

Objectives Currently, patients with persistent moderate-to-severe house dust mite (HDM) allergic rhinitis despite use of symptom-relieving medication can be offered subcutaneously administered allergy immunotherapy (SQ SCIT; Alutard SQ) as standard care of treatment in Denmark. Recently, a HDM sublingually administered allergy immunotherapy tablet (SQ SLIT-tablet; ACARIZAX) has been developed for at-home treatment. The purpose of this analysis is to compare the costs related to treatment and administration of SQ SLIT-tablet and SQ SCIT. Methods Assuming equal efficacy between ther SQ SLIT-tablet and SQ SCIT, the cost-minimization analysis was the most appropriate for the comparison. According to guidelines and Summary of Product Characteristics, the treatment duration of SQ SLIT-tablet is 3 years and 3-5 years for SQ SCIT. The courses of treatment vary among patients and, therefore, the costs of treatment have been calculated for an average patient with HDM respiratory allergic disease (RAD) receiving either SQ SLIT-tablet or SQ SCIT. All costs associated with allergy immunotherapy were collected, i.e., cost of medication, administration and treatment setting, and discounted according to Danish guidelines. Comprehensive univariate sensitivity analyses were carried out. Results The treatment costs for an average patient with HDM RAD are €3094 for SQ SLIT-tablet and €3799 for SQ SCIT; however, when adding indirect costs to the calculations the total costs of the treatments are €3697 and €6717 for SQ SLIT-tablet and SQ SCIT, respectively. Therefore, if 2500 patients with HDM RAD were treated with SQ SLIT-tablet instead of SQ SCIT, it would elicit a saving to the healthcare system of ∼€1.8 million. The conclusion was robust to any changes in the sensitivity analysis. Conclusion With regards to the cost of treating Danish patients with HDM RAD, it is clearly cost-saving to treat patients with SQ SLIT-tablet compared to SQ SCIT.

Patient engagement and patient support programs in allergy immunotherapy: a call to action for improving long-term adherence

Allergy immunotherapy (AIT) is acknowledged to produce beneficial mid- and long-term clinical and immunologic effects and increased quality of life in patients with allergic respiratory diseases (such as allergic rhinoconjunctivitis and allergic asthma). However, poor adherence to AIT (due to intentional and/or non-intentional factors) is still a barrier to achieving these benefits. There is an urgent need for patient support programs (PSPs) that encompass communication, educational and motivational components. In the field of AIT, a PSP should be capable of (1) improving adherence, (2) boosting patient engagement, (3) explaining how AIT differs from pharmacological allergy treatments; (4) increasing health literacy about chronic, progressive, immunoglobulin-E-mediated immune diseases, (5) helping the patient to understand and manage local or systemic adverse events, and (6) providing and/or predicting local data on aeroallergen levels. We reviewed the literature in this field and have identified a number of practical issues to be addressed when implementing a PSP for AIT: the measurement of adherence, the choice of technologies, reminders, communication channels and content, the use of "push" messaging and social networks, interactivity, and the involvement of caregivers and patient leaders. A key issue is "hi-tech" (i.e. approaches based mainly on information technology) vs. "hi-touch" (based mainly on interaction with humans, i.e. family members, patient mentors and healthcare professionals). We conclude that multistakeholder PSPs (combining patient-, provider and society-based actions) must now be developed and tested with a view to increasing adherence, efficacy and safety in the field of AIT.

Comparison of allergenic extracts from different origins: the value of the FDA's bioequivalent allergy unit (BAU)

INTRODUCTION

Allergy immunotherapy (AIT) is the only disease-modifying intervention for the treatment of allergic diseases. The clinical effectiveness of AIT is clearly dose-dependent, so it is important that clinicians can assess and compare the potency of the various products available. However, this is not possible in practice, because manufacturers use different methods to determine potency. Therefore, a clear need exists for adoption of a 'gold-standard' measure of allergenicity. The bioequivalent allergy unit (BAU) is thus far the only allergen unit approved by a regulatory agency (the US Food and Drug Administration), with European regulatory authorities yet to adopt a common unit.

AREAS COVERED

Using PubMed, we performed a review of the literature on measures of allergen extract potency, use of the BAU, and BAU assessment for grass pollen tablets. Expert commentary: There is an obvious benefit to allergists and patients for having a single, comparable unit across products, and we strongly support the adoption of a single, 'gold-standard' unit of measurement for all products. Use of the BAU allows a clear comparison of the potency of allergen products from different manufacturers, and enables better understanding of the potential reasons for any differences in administration and dosing protocols between these products.

Effective treatment of house dust mite-induced allergic rhinitis with 2 doses of the SQ HDM SLIT-tablet: Results from a randomized, double-blind, placebo-controlled phase III trial

BACKGROUND

The SQ HDM SLIT-tablet (ALK) has been developed for treatment of house dust mite (HDM)-induced respiratory allergic disease.

OBJECTIVE

This trial investigated the efficacy and safety of the SQ HDM SLIT-tablet in adults with moderate-to-severe HDM-induced allergic rhinitis (AR).

METHODS

The trial was a randomized, double-blind, placebo-controlled phase III trial conducted in 12 European countries including 992 adults with moderate-to-severe HDM-induced AR despite treatment with pharmacotherapy. Subjects were randomized 1:1:1 to 1 year of daily treatment with placebo, 6 SQ-HDM, or 12 SQ-HDM. The primary end point was the total combined rhinitis score (ie, the sum of rhinitis symptom and medication scores) during the efficacy assessment period (approximately the last 8 weeks of the treatment period). Key secondary end points were rhinitis symptoms, medication scores, quality of life, and the combined rhinoconjunctivitis score.

RESULTS

Analysis of the primary end point (observed data) demonstrated absolute reductions in total combined rhinitis score of 1.18 (P = .002) and 1.22 (P = .001) compared with placebo for 6 SQ-HDM and 12 SQ-HDM, respectively. The statistically significant treatment effect was evident from 14 weeks of treatment onward. For all key secondary end points, efficacy was confirmed for 12 SQ-HDM, with statistically significant reductions of rhinitis symptoms and medication scores, improved quality of life, and a reduced combined rhinoconjunctivitis score in the efficacy assessment period compared with placebo. The treatment was well tolerated.

CONCLUSION

The trial confirmed the efficacy and favorable safety profile of both 6 SQ-HDM and 12 SQ-HDM in adults with HDM-induced AR. The treatment effect was present from 14 weeks of treatment onward.

Allergy immunotherapy with a hypoallergenic recombinant birch pollen allergen rBet v 1-FV in a randomized controlled trial

BACKGROUND

Pollen extracts and chemically modified allergoids are used successfully in allergen immunotherapy (AIT). Recombinant extracts offer potential advantages with respect to pharmaceutical quality, standardization and dosing. A hypoallergenic recombinant folding variant of the major birch pollen allergen (rBet v 1-FV) was compared with an established native birch preparation. A pre-seasonal, randomized, actively controlled phase II study was performed in birch pollen allergic rhino-conjunctivitis with or without asthma, GINA I/ II. 51 patients (24 rBet v 1-FV, 27 native extract) started therapy with subcutaneous allergen immunotherapy (SCIT). Primary end-point was a combined symptom medication score (SMS), changes in nasal provocation test, visual rating score and specific antibody responses secondary end-points.

FINDINGS

After one pre-seasonal treatment course the combined SMS was 5.86 (median; IQR: 14.02) for the rBet v 1-FV group versus 12.40 (median; IQR: 9.32) for the comparator during the three weeks pollen season (p = 0.330). After treatment in the second year, scores were 3.00 (median; IQR: 6.50) and 2.93 (4.86) respectively. Allergen tolerance in a nasal provocation test improved to a comparable extent in both groups. Significant increases in birch pollen-specific IgG1 and IgG4 were observed in both treatment groups following the first treatment phase and remained significantly raised until the end of the study.

CONCLUSION

In this first in man, proof of concept phase II trial no statistical difference between rBet v 1-FV and an established natural pollen extract could be observed. rBet v 1-FV could be administered in higher doses than the native protein with no increase in adverse effects.

TRIAL REGISTRATION

The study was registered in clinicalTrials.gov (NCT00266526).

Allergy immunotherapy safety: location matters!

Allergy immunotherapy is a highly effective therapy that has been used in the treatment of allergic rhinitis, asthma, and venom allergy for over a century. Subcutaneous immunotherapy (SCIT) is currently the only US Food and Drug Administration approved form of allergy immunotherapy. In this commentary, we address the safety issues that surround the location of care of SCIT administration in a supervised medical facility versus in the home or other medically unsupervised facility. Although analysis of the data suggests that SCIT has an excellent safety profile, we believe that this safety is largely due to the safety measures that are implemented when SCIT is administered in a medically supervised setting with appropriate staff and equipment to immediately recognize and treat anaphylaxis. In the home or medically unsupervised setting, the preinjection health assessment may not be adequate and access to immediate emergency medical treatment is unlikely to occur. We strongly urge all health care providers to adhere to the current Allergy Immunotherapy Practice Parameter recommendations and that patients be appropriately assessed before and monitored after allergy immunotherapy injections in a medically supervised facility.