A practical guide to the sublingual immunotherapy tablet adverse event profile: implications for clinical practice

Allergen Immunotherapy: The Evidence Supporting the Efficacy and Safety of Subcutaneous Immunotherapy and Sublingual Forms of Immunotherapy for Allergic Rhinitis/Conjunctivitis and Asthma

Allergen immunotherapy (AIT) is a recognized key therapeutic modality for the treatment of allergic respiratory disease. Definitive studies have provided evidence-based data to demonstrate its effectiveness in allergic rhinitis and asthma due to the inhalation of proteinaceous allergic substances from specific seasonal pollens, dust mites, animal allergens, and certain mold spores. Over the ensuing decades, laboratory investigations have provided objective evidence to demonstrate immunologic changes, including production of protective IgG antibody, suppression of IgE antibody, upregulation of regulatory T cells, and induction of a state of immune tolerance to the offending allergen(s). Tangential to this work were carefully designed clinical studies that defined allergen dose and duration of treatment, established the importance of preparing extracts with standardized allergens (or well-defined extracts) based on major protein moieties, and used allergen provocation models to demonstrate efficacy superior to placebo. In the United States, the use of subcutaneous immunotherapy extracts for AIT was grandfathered in by the Food and Drug Administration based on expert literature review. In contrast, sublingual tablet immunotherapy underwent formal clinical development programs (phase I-III clinical trials) that provided the necessary clinical evidence for safety and efficacy that led to regulatory agency approvals for the treatment of allergic rhinitis in properly characterized patients with allergy. The allergy specialist's treatment options currently include traditional subcutaneous AIT and specific sublingual tablets approved for grass, ragweed, house dust mites, trees belonging to the birch-homologous group, and Japanese cedar. Tangential to this are sublingual drops that are increasingly being used off-label (albeit not approved by the Food and Drug Administration) in the United States. This article will review the evidence-based literature supporting the use of these forms of AIT, as well as focus on several current controversies and gaps in our knowledge base that have relevance for the appropriate selection of patients for treatment with specific AIT.

Tolerability of sublingual versus vestibular allergy immunotherapy tablet administration: A randomized pilot study

BACKGROUND

Local application site reactions are common with sublingual allergy immunotherapy (AIT)-tablets for the treatment of allergic rhinitis/conjunctivitis (AR/C) and occasionally lead to treatment discontinuation. Because of the lower mast cell density in the vestibular mucosa than the sublingual area, vestibular AIT-tablet administration may result in fewer adverse events (AEs). This pilot study evaluated the tolerability of the vestibular administration route of AIT-tablets compared with the sublingual route in adult subjects with AR/C.

METHODS

Adults (n = 164) aged 18-65 years with AR/C treated with daily birch pollen, grass pollen, ragweed pollen or house dust mite AIT in tablet form were randomized 1:1 to vestibular or sublingual administration for 28 days, followed by 28 days of sublingual administration only. The primary endpoint was the severity (mild, moderate, severe) of local treatment-related adverse events (TRAEs) during the first 28 days of treatment.

RESULTS

During the first 28 days, the percentage of subjects in the vestibular and sublingual groups reporting mild TRAEs were 55.6% versus 50.6%, respectively; moderate TRAEs were 27.2% versus 30.1%; and severe TRAEs were 12.3% versus 6.0% (p = .16). In the vestibular group, 95.1% of the subjects experienced at least one TRAE during the first period versus 81.9% in the sublingual group (p = .01) and discontinuation rates due to AEs were higher (12.3% vs. 3.6%).

CONCLUSION

The frequencies of subjects experiencing severe TRAEs, at least one TRAE, and discontinuations due to AEs at the initiation of AIT-tablets were numerically higher with vestibular administration than sublingual administration. Sublingual administration should remain the standard of care for subjects treated with AIT-tablets for AR/C.

How to handle off-label prescriptions of rupatadine, a second-generation antihistamine and PAF antagonist: a review

The off-label use of second-generation antihistamines, used outside of the formal indications authorized by regulatory authorities, in different age groups, doses or in special populations, is very common for many allergic, autoimmune and dermatological diseases. The off-label use of rupatadine (a second-generation antihistamine with PAF antagonist activity) in these conditions is reviewed here, including in combination with immunotherapy in the treatment of food allergy or allergic rhinitis, at high doses in chronic urticaria, and with prescriptions of less common but challenging conditions such as skin pruritus or mast cell activation disorders like mastocytosis. Rupatadine use is reviewed herein to confirm if its off-label management is supported by well-designed clinical trials or by published real-world cases. This review will contribute to increasing compliance and achieving better results in clinical practice. Off-label use of rupatadine should be left to the discretion of the prescribing healthcare professional after careful clinical evaluation.

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.

A practical guide to prescribing sublingual immunotherapy tablets in North America for pediatric allergic rhinoconjunctivitis: an injection-free allergy immunotherapy option

Allergic rhinoconjunctivitis (ARC) is a common disease that affects individuals of all ages. Pediatricians may be the first (and only) point of care for children with ARC. Sublingual immunotherapy (SLIT)-tablets are a convenient at-home, injection-free allergy immunotherapy option that can be used for the treatment of ARC. This paper provides a practical guide for pediatricians to aid in prescribing SLIT-tablets to children with ARC in North America. Topics include a summary of the available SLIT-tablets and their efficacy and safety, guidance on when SLIT-tablets are an appropriate option, and how to diagnose ARC and identify culprit allergens. Practical guidance is also provided through a proposed decision tree, a prescribing checklist and prescribing procedures, and suggested follow-up assessments.

Is immunotherapy safe for treatment of severe asthma

PURPOSE OF REVIEW

The benefits of allergen immunotherapy (AIT), including subcutaneous allergen immunotherapy (SCIT) and sublingual allergen immunotherapy (SLIT), for IgE-mediated asthma are well established, especially for dust mite. This review will explore whether the benefits of AIT outweigh the risks in severe asthmatic patients.

RECENT FINDINGS

Studies have mostly included mild and moderate asthmatic patients, but at least a few studies do show improvements in asthma symptoms and medication use in severe asthmatic patients. Asthma, and especially uncontrolled asthma, is a major risk factor for severe and fatal systemic reactions from SCIT. Uncontrolled asthma is an absolute contraindication for SCIT. It is less clear whether the benefits of SCIT and SLIT may outweigh the risks in well controlled, severe asthmatic patients, and further study is needed in this area. Asthma biologics, especially Omalizumab, may improve outcomes in severe, controlled asthmatic patients on SCIT, but further data are needed regarding timing of initiation and duration of treatment.

SUMMARY

Although severe asthmatic patients may benefit from AIT, significant risks exist, especially in those with uncontrolled asthma. Further study is needed regarding optimal strategies to minimize risks.

Efficacy and safety of sublingual allergen immunotherapy

Sublingual immunotherapy (SLIT)-tablets represent a new allergen immunotherapy option for clinicians. In North America, there are five SLIT-tablets approved for the treatment of allergic rhinoconjunctivitis (ARC). No SLIT-drops products are currently approved in the United States or Canada. This work reviewed the efficacy of the timothy grass SLIT-tablet, five-grass SLIT-tablet, ragweed SLIT-tablet, house-dust mite SLIT-tablet, and tree SLIT-tablet in patients with ARC. All the SLIT-tablets showed consistent clinical efficacy for the treatment of ARC in large, double-blind, placebo-controlled trials, including for both patients who were monosensitized and those who were polysensitized. Treatment with house-dust mite SLIT-tablet has shown efficacy in patients who are pollen sensitized during their respective pollen seasons. In contrast to SLIT-tablets, efficacy studies of SLIT-drops show high heterogeneity of treatment effect. Although data are scarce, data that compared the efficacy of SLIT-tablets versus ARC pharmacotherapy generally indicated that SLIT-tablets had a greater benefit than pharmacotherapy when compared with placebo, particularly for perennial ARC. When compared with subcutaneous immunotherapy, analysis of these data indicated that SLIT-tablets had a benefit over subcutaneous immunotherapy in regard to safety but somewhat less benefit in regard to efficacy. The safety of SLIT-tablets has been well documented, and a U.S. Food and Drug Administration class label with safety considerations is present in the prescribing information for all SLIT-tablets. No new safety signals have been observed after reinitiating SLIT-tablets after a short treatment interruption.

Delivery options for sublingual immunotherapy for allergic rhinoconjunctivitis: clinical considerations for North America

Background: Sublingual immunotherapy (SLIT) can be delivered via tablets (SLIT-T) or aqueous drops (SLIT-D). SLIT-D dosing recommendations using North American extracts were published in 2015. We review the 2015 recommendations in the context of recent research, and compare and contrast dosing, efficacy, safety, adherence, and cost of SLIT-T and SLIT-D for allergic rhinoconjunctivitis (ARC) in North America. Methods: Randomized controlled trials (RCT) of SLIT-D and SLIT-T trials were identified by a systematic PubMed search through March 1, 2022. Results: Dose-finding studies have been conducted for all approved SLIT-T; efficacy in North American populations was demonstrated in 11 RCTs. Approved SLIT-T are uniform internationally. Few dose-finding studies for SLIT-D have been conducted using North American extracts; efficacy was demonstrated in 2 RCTs. Extrapolation of dosing from SLIT-D studies conducted with extracts from other geographic regions is unreliable. Since the 2015 SLIT-D dosing recommendations, no new RCTs of SLIT-D have been conducted with North American extracts, whereas 6 SLIT-T RCTs have since been conducted in North America. Local allergic reactions are the most common adverse events with SLIT-T and SLIT-D, but both can induce systemic allergic reactions. Adherence to SLIT-D and SLIT-T remains a challenge. Patients must pay for SLIT-D directly, whereas SLIT-T is usually covered by insurance. Conclusion: As part of shared decision-making, patients should be informed about the scientific evidence supporting the use of SLIT-T and SLIT-D for ARC.

Rupatadine to prevent local allergic reactions to sublingual allergy immunotherapy: a case series

BACKGROUND

Sublingual immunotherapy tablets (SLIT-T) are an effective treatment for allergic rhinitis (AR), but some patients experience local allergic reactions (LAR) in the first few weeks of treatment that can lead to treatment discontinuation. Although oral antihistamines are recommended for the treatment and pretreatment of LAR associated with SLIT-T, there are no clinical trial data to support this recommendation. Rupatadine is an H1 antihistamine that also inhibits platelet activating factor activity. The objective of this case series is to describe real-world clinical situations in which rupatadine was used to treat or mitigate SLIT-T-related LAR.

CASE PRESENTATIONS

Five cases are presented by the managing allergist and off-label use of rupatadine is their expert opinion only. Patients in all 5 cases were treated with a SLIT-T (e.g. ragweed, tree, grass, or house dust mites) for the management of allergic rhinitis and experienced bothersome LAR with the first SLIT-T administration. In 3 cases, rupatadine 10 mg was administered for the immediate treatment of LAR (either in-office with the first SLIT-T dose or for subsequent LAR experienced at home) and the symptoms resolved. In 3 cases, pretreatment with other second-generation H1 antihistamines was unable to prevent LAR and the patients discontinued the SLIT-T. In these 3 cases, switching to pretreatment with rupatadine allowed the patients to restart and tolerate SLIT-T treatment with minimal or no LAR. In these patients with an established history of LAR, proactive pretreatment with rupatadine in subsequent seasons or with initiation of a different SLIT-T mitigated the previously experienced LARs.

CONCLUSIONS

In the cases presented, treatment with rupatadine resolved LAR associated with SLIT-T treatment and rupatadine pretreatment appeared to mitigate subsequent LAR. Rupatadine may be an option to treat or improve the tolerability of the SLIT-T, potentially improving early treatment persistence.

Safety of the standardized quality tree sublingual immunotherapy tablet: Pooled safety analysis of clinical trials

BACKGROUND

The standardized quality (SQ) tree sublingual immunotherapy (SLIT)-tablet has recently been approved for treatment of tree pollen allergy. Healthcare workers should be provided with detailed safety data for clinical use.

OBJECTIVE

To assess the tolerability and safety of the SQ tree SLIT-tablet (12 SQ-Bet) in adults and adolescents.

METHODS

Safety data were pooled from three double-blinded, randomized, placebo-controlled trials (2 phase-II/1 phase-III) including adults and adolescents 12-65 years with allergic rhinitis and/or conjunctivitis treated before and during one pollen season once-daily with 12 SQ-Bet (n = 471) or placebo (n = 458): EudraCT no: 2012-000031-59; NCT02481856; EudraCT 2015-004821-15.

RESULTS

The most frequently reported investigational medicinal product (IMP)-related AEs with 12 SQ-Bet were oral pruritis (39% of subjects) and throat irritation (29%). IMP-related AEs were mainly mild or moderate in severity, and the majority resolved without treatment and did not lead to treatment interruption/discontinuation. With 12 SQ-Bet, oral pruritus was more frequent among subjects with pollen food syndrome (PFS) (45%) than without PFS (29%). The 12 SQ-Bet did not seem to induce an increased risk of asthma: 7 events were reported in 7 subjects with 12 SQ-Bet and 11 in 10 subjects with placebo. No differences were seen in the risk of moderate-to-severe IMP-related AEs regardless of age, PFS status and asthma medical history.

CONCLUSIONS

The 12 SQ tree SLIT-tablet was well tolerated in tree pollen allergic subjects with no major safety concerns detected. This safety profile supports daily at-home sublingual administration once the first dose is tolerated when administered under medical supervision.

Randomized controlled trial of ragweed sublingual immunotherapy tablet in the subpopulation of Canadian children and adolescents with allergic rhinoconjunctivitis

Background

Post hoc analyses of randomized placebo-controlled trials have demonstrated efficacy and tolerability of the ragweed sublingual immunotherapy (SLIT)-tablet in Canadian adults with ragweed pollen-induced allergic rhinitis/conjunctivitis (AR/C). This post hoc analysis evaluated the efficacy and tolerability of the ragweed SLIT-tablet in the subpopulation of Canadian children and adolescents with AR/C in a previously described randomized, double-blind, placebo-controlled trial.

Methods

The trial (NCT02478398) was conducted in North American and European children/adolescents ages 5–17 years with ragweed pollen-induced AR/C with or without asthma (FEV1 ≥ 80% predicted). Participants were randomized to daily ragweed SLIT-tablet (12 Amb a 1-U) or placebo for up to 28 weeks. The primary endpoint was the average total combined score (TCS; sum of rhinoconjunctivitis daily symptom score [DSS] and daily medication score [DMS]) during peak ragweed pollen season (RPS). Key secondary endpoints were TCS during the entire RPS, and DSS and DMS during peak RPS. Post hoc analyses of the primary and key secondary endpoints were conducted in the subpopulation of Canadian participants.

Results

Of the 1025 randomized participants, 246 (SLIT-tablet, n = 116; placebo, n = 130) were in the Canadian subpopulation. In the total study population, relative TCS (95% CI) improvement with ragweed SLIT-tablet versus placebo was − 38.3% (− 46.0%, − 29.7%; least square [LS] mean difference, − 2.73; P < 0.001) during peak RPS. In the Canadian subpopulation, relative TCS improvements with ragweed SLIT-tablet versus placebo were − 40.8% (− 54.5%, − 20.2%; LS mean difference, − 1.59; P = 0.001) during peak RPS and − 36.6% (− 50.2%, − 16.5%; LS mean difference, − 1.36; P = 0.002) during the entire RPS. DSS and DMS during peak RPS in the Canadian subpopulation improved with SLIT-tablet versus placebo by − 30.6% (− 45.2%, − 7.7%; LS mean difference, − 0.94; P = 0.010) and − 77.2% (− 97.5%, − 44.2%; LS mean difference, − 0.66; P = 0.003), respectively. No events of anaphylaxis, airway compromise, intramuscular epinephrine administration, eosinophilic esophagitis, or severe treatment-related systemic allergic reactions were reported in the overall population or Canadian subpopulation.

Conclusion

Efficacy and safety of the ragweed SLIT-tablet in Canadian children/adolescents with ragweed pollen-induced AR/C was consistent with the total study population. The ragweed SLIT-tablet resulted in clinically meaningful improvement in symptoms, decreased symptom-relieving medication use, and was well tolerated in Canadian children/adolescents.

Trial registration: clinicaltrials.gov, NCT02478398. Registered June 23, 2015, https://clinicaltrials.gov/ct2/show/NCT02478398?term=NCT02478398&draw=2&rank=1

Systemic Allergic Reactions and Anaphylaxis Associated with Allergen Immunotherapy

Subcutaneous allergen immunotherapy (SCIT) is a proven treatment of allergic rhinitis, asthma, atopic dermatitis, and prevention of Hymenoptera venom anaphylaxis. The known benefit of SCIT, however, must be considered in each patient relative to the potential risks of systemic allergic reactions (SRs). A mean of 1 SR per 1000 injection visits (0.1%) was estimated to occur between 2008 and 2018. Life-threatening anaphylactic events are estimated to occur in 1/160,000 injection visits. The factors that contribute to SRs and fatal reactions (FRs) are reviewed. Risk management strategies are proposed to prevent and decrease future SCIT associated with SRs, anaphylaxis, and FR.

Recent development on the use of sublingual immunotherapy tablets for allergic rhinitis

OBJECTIVE

Allergic rhinitis (AR) is an immunoglobulin (Ig) E-mediated inflammatory condition that causes sneezing, nasal congestion, rhinorrhea, and nasal itch. Although subcutaneous immunotherapy for the treatment of AR has been in use and well established as a treatment modality, sublingual immunotherapy (SLIT) is increasingly considered to be the safer and more convenient alternative. Thus, the objective of this review is to describe recent findings pertaining to the use of SLIT tablets (SLIT-T) for AR.

DATA SOURCES

A database search (PubMed.gov) for articles published between January 1, 2017, and February 9, 2021, was conducted using the following key words: "allergic rhinitis," AND-ed "sublingual immunotherapy." Included were randomized placebo-controlled trials. Other experimental design studies were excluded.

STUDY SELECTIONS

A total of 11 randomized placebo-controlled trials were selected for full-text review and included in the analysis. All studies investigated the use of SLIT on patients with seasonal AR (4 tree pollen, 1 grass pollen, and 1 Japanese cedar) or perennial AR (3 house dust mite).

RESULTS

Our review of 7 recently published randomized placebo-controlled trials with 2348 subjects receiving SLIT reported increased efficacy, safety, supportive immunologic parameters (IgE and IgG4 pre- and posttreatment levels), and improved quality of life. All studies excluded subjects with overlapping seasonal or perennial allergens, a history of moderate-to-severe uncontrolled asthma, or reduced lung function.

CONCLUSION

Our review highlights that SLIT is a safe and effective treatment that considerably reduces symptoms and medication requirements in AR and improves quality of life.

The safety of sublingual immunotherapy, can the rare systemic reactions be prevented?

Introduction: The safety of subcutaneous immunotherapy (SCIT), and particularly the dramatic issue of fatal reactions, has been an obstacle that limited the implementation of a therapy with unique characteristics of action on the causes of allergy. The introduction of sublingual immunotherapy (SLIT) was aimed at solving safety problems while maintaining clinical efficacy.Areas covered: For more than 20 years, SLIT has been based on allergen extracts in drops at low average doses. As evidenced by meta-analyses, the typical adverse events (AE) have consisted of local reactions in the mouth and throat. Unlike the injection route, no correlation was observed between the administered dose and AEs. The development of SLIT products in tablets, based on higher doses than drops, has somewhat changed the concept of SLIT safety. Although large trials, performed to obtain regulatory agency approval, have shown overall high safety, rare anaphylactic reactions have been described.Expert opinion: SLIT is globally safe, and no fatal reactions have ever been reported, but with currently available high biological potency products it is necessary to follow prudential rules, such as the administration of the first dose under medical supervision and the thorough education of patients to avoid taking of higher doses than recommended.

Preference for Immunotherapy with Tablets by People with Allergic Rhinitis

BACKGROUND

People with allergic rhinitis (AR) who are not controlled on conventional therapy can be treated using allergy immunotherapy (AIT) administered as tablets, injections or drops. In the US, the use of sublingual immunotherapy as tablets (SLIT-tablets) is limited in comparison to subcutaneous immunotherapy (SCIT).

OBJECTIVE

This study investigated patients' preference for SLIT-tablets vs monthly or weekly SCIT from a US patient perspective.

METHODS

We carried out a discrete choice experiment (DCE) consisting of two blocks with eight choice sets. Adults and caregivers of children with moderate-to-severe AR were included if they had not previously or were not currently receiving AIT. Three attributes were included in the design: the mode and frequency of administration, the risk of systemic reactions and the co-payment.

RESULTS

A total of 724 adults with AR and 665 caregivers of children with AR were included in the study. Both adults and caregivers had a significant preference for SLIT-tablets compared with both weekly and monthly injections and for less risk of anaphylactic shock. Caregivers were more risk-averse than adults when choosing their treatment, and the younger the child, the more risk-averse the caregiver. The preference for SLIT-tablets was found for both monoallergic and polyallergic adults and caregivers of monoallergic and polyallergic children. Respondents not wanting AIT for free were more risk-averse than those indicating that they wanted AIT for free.

CONCLUSION

Our findings suggest that SLIT-tablets is the preferred route of administration for AIT among adults and caregivers of children with AR.

The evolution of allergy immunotherapy

OBJECTIVE

The objective of this review is to trace the evolution of the art and science of allergy immunotherapy (AIT).

DATA SOURCES

Original reports relating to the evolution of the concept of respiratory allergy and its specific treatment were identified by following references in journal articles, review articles, and allergy textbooks from the mid-20th century to the present.

STUDY SELECTIONS

Studies highlighting substantial milestones in the evolution of the practice of allergy immunotherapy were included.

RESULTS

The story of AIT begins with the recognition of hay fever as a distinct entity and subsequent studies that established grass pollen as one of the causes. This knowledge led several investigators, most notable Leonard Noon and John Freeman who worked at St. Mary's Hospital in London, to attempt to induce tolerance giving grass pollen extract by injection to their patients. After the publication of the work of Noon and Freeman in 1911, the practice of AIT spread rapidly and was applied to many other pollen allergens besides grass and for perennial rhinitis and asthma. The early studies were largely anecdotal, but over the past 60 to 70 years, studies of AIT have been conducted with increasingly sophisticated scientific methods. Nowadays, not only is the practice of AIT based on carefully conducted studies, but the underlying immunologic basis of allergy and the response to AIT have also been and still are being firmly established.

CONCLUSION

Both the art and the science behind the practice of AIT have been established by a solid base of clinical and immunologic studies.

Eosinophilic esophagitis during sublingual and oral allergen immunotherapy

PURPOSE OF REVIEW

The aim of this review is to discuss the current evidence regarding the development of eosinophilic esophagitis (EoE) in individuals undergoing oral and sublingual immunotherapy (SLIT) for both food and environmental allergens. Cumulative incidence of EoE in patients on allergen immunotherapy for peanut, milk, and egg is estimated.

RECENT FINDINGS

De novo development of EoE in patients undergoing oral and SLIT has been demonstrated on the scale of case reports and prospective randomized trials. However, few individuals with EoE-like symptoms during immunotherapy undergo endoscopy, and the long-term outcomes of immunotherapy-associated EoE are unknown.

SUMMARY

Evidence exists to suggest that allergen immunotherapy could place individuals at risk for the development of EoE, the true incidence of which may vary depending on antigen exposure and methods used to define the condition.

Sublingual Versus Subcutaneous Immunotherapy for Allergic Rhinitis: What Are the Important Therapeutic and Real-World Considerations?

PURPOSE OF REVIEW

Allergen immunotherapy has been used for over 100 years in the treatment of allergic rhinitis. With two major options for administering this disease-modifying therapy, SCIT, and SLIT, what is our current understanding of the efficacy and safety of each one? How do we determine who is the appropriate candidate for each one in the real world?

RECENT FINDINGS

SCIT and SLIT show significant improvement in clinical symptoms and need for medication in the treatment of allergic rhinitis. In recent meta-analyses, there is no significant difference in the efficacy between the two treatments, but SLIT has more local side effects though less systemic ones. Shared decision-making should be instituted to determine which treatment should be started in a patient with allergic rhinitis. This review provides up-to-date information on the efficacy and safety of SCIT vs SLIT in the care of children and adults with allergic rhinitis in the real world and the role of shared decision-making in the use of these modalities.

TRIAL REGISTRATIONS

Clinicaltrials.gov: NCT04145219 and NCT02478398.

Towards definitive management of allergic rhinitis: best use of new and established therapies

BACKGROUND

Allergic rhinitis (AR) is an inflammatory disease of the nasal mucosa impacting up to 25% of Canadians. The standard of care for AR includes a treatment plan that takes into account patient preferences, the severity of the disease, and most essentially involves a shared decision-making process between patient and provider.

BODY

Since their introduction in the 1940s, antihistamines (AHs) have been the most utilized class of medications for the treatment of AR. First-generation AHs are associated with adverse central nervous system (CNS) and anticholinergic side effects. On the market in the 1980s, newer generation AHs have improved safety and efficacy. Compared to antihistamines, intranasal corticosteroids (INCS) have significantly greater efficacy but longer onset of action. Intranasal AH and INCS combinations offer a single medication option that offers broader disease coverage and faster symptom control. However, cost and twice-per-day dosing remain a major limitation. Allergen immunotherapy (AIT) is the only disease-modifying option and can be provided through subcutaneous (SCIT) or sublingual (SLIT) routes. While SCIT has been the definitive management option for many years, SLIT tablets (SLIT-T) have also been proven to be safe and efficacious.

CONCLUSION

There is a range of available treatment options for AR that reflect the varying disease length and severity. For mild to moderate AR, newer generation AHs should be the first-line treatment, while INCS are mainstay treatments for moderate to severe AR. In patients who do not respond to INCS, a combination of intranasal AH/INCS (AZE/FP) should be considered, assuming that cost is not a limiting factor. While SCIT remains the option with the most available allergens that can be targeted, it has the potential for severe systemic adverse effects and requires weekly visits for administration during the first 4 to 6 months. SLIT-T is a newer approach that provides the ease of being self-administered and presents a reduced risk for systemic reactions. In any case, standard care for AR includes a treatment plan that takes into account disease severity and patient preferences.

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.

Efficacy and Safety of Ragweed SLIT-Tablet in Children with Allergic Rhinoconjunctivitis in a Randomized, Placebo-Controlled Trial

BACKGROUND

Ragweed sublingual immunotherapy (SLIT) tablet reduces symptoms and symptom-relieving medication use in adults with allergic rhinitis with or without conjunctivitis (AR/C) but has not been evaluated in children.

OBJECTIVE

This international, multicenter, double-blind, placebo-controlled trial evaluated the efficacy and safety of ragweed SLIT-tablet in children with AR/C.

METHODS

Children (N = 1025; 77.7% polysensitized) aged 5 to 17 years with ragweed pollen-induced AR/C with or without asthma (FEV₁ ≥80% predicted) were randomized 1:1 to daily ragweed SLIT-tablet (12 Amb a 1-Unit) or placebo for up to 28 weeks (NCT02478398). The primary end point was the average total combined score (TCS; sum of rhinoconjunctivitis daily symptom score [DSS] and daily medication score [DMS]) during peak ragweed pollen season (RPS). Key secondary end points were TCS during the entire RPS, and DSS and DMS during the peak RPS.

RESULTS

Relative TCS (95% CI) improvements with ragweed SLIT-tablet versus placebo were -38.3% (-46.0% to -29.7%; least square [LS] mean difference, -2.73; P < .001) during peak RPS and -32.4% (-40.7% to -23.3%; LS mean difference, -1.86; P < .001) during the entire RPS. DSS and DMS during peak RPS improved with SLIT-tablet versus placebo by -35.4% (-43.2% to -26.1%; LS mean difference, -1.40; P < .001) and -47.7% (-59.8% to -32.5%; LS mean difference, -1.84; P < .001), respectively. Asthma DSS, short-acting β-agonist use, and nocturnal awakenings during peak RPS improved with SLIT-tablet versus placebo by -30.7%, -68.1%, and -75.1%, respectively (all nominal P ≤ .02). No events of anaphylaxis, airway compromise, or severe treatment-related systemic allergic reactions were reported.

CONCLUSIONS

Ragweed SLIT-tablet significantly improved symptoms and decreased symptom-relieving medication use in children with ragweed pollen-induced AR/C and was well tolerated.

Safety of Timothy Grass Sublingual Immunotherapy Tablet in Children: Pooled Analyses of Clinical Trials

BACKGROUND

Timothy grass sublingual immunotherapy (SLIT) tablets are indicated for children with allergic rhinitis with or without conjunctivitis.

OBJECTIVE

To use pooled analyses to assess the short- and long-term tolerability and safety of timothy grass SLIT-tablet in children.

METHODS

Data from 9 double-blinded, randomized European or North American trials that included children with allergic rhinitis with or without conjunctivitis treated up to 3 years with once-daily timothy grass SLIT-tablet or placebo were pooled.

RESULTS

In all, 1818 (timothy grass SLIT-tablet, n = 923; placebo, n = 895) subjects were included in the analysis. The frequency of treatment-emergent adverse events (AEs) was 86% in the SLIT-tablet group and 83% in the placebo group, and the frequency of treatment-related AEs (TRAEs) was 59% and 23%, respectively. Most (98%) TRAEs were mild to moderate in severity. The 2 most common TRAEs with SLIT-tablet were oral pruritus (33%) and throat irritation (19%), which had a median onset of 1 day and recurrence of 14.5 and 5 days, respectively. In all, 8% of subjects in the SLIT-tablet group and 2% in the placebo group discontinued because of AEs. There were 7 serious AEs assessed as related to SLIT-tablet, 1 systemic allergic reaction (severe with a drop in blood pressure), 3 epinephrine administrations, no eosinophilic esophagitis events, and no serious airway obstructions. The safety profile was similar in subjects across geographic regions and with and without asthma.

CONCLUSIONS

Pooled data indicate that short- and long-term timothy grass SLIT-tablet is well tolerated in children, regardless of geographic region. AEs were generally local, mild, and transient allergic reactions.

Clinical aspects of sublingual immunotherapy tablets and drops

BACKGROUND

Sublingual immunotherapy (SLIT) is administered via tablets (SLIT-T) or liquid drops (SLIT-D). In North America, currently 4 SLIT-T formulations are approved by the US Food and Drug Administration for allergy immunotherapy, and SLIT-D is an off-label use of subcutaneous immunotherapy (SCIT) extracts.

OBJECTIVE

To compare and contrast aspects of SLIT-T and SLIT-D, including physical characteristics, mechanism of action, dosing, efficacy, safety, adherence, and cost.

DATA SOURCES

PubMed literature review (no limits), product prescribing information, and manufacturer websites.

STUDY SELECTIONS

Publications related to physical characteristics, mechanism of action, dosing, efficacy, safety, and adherence.

RESULTS

Published evidence indicates that tablet and drop formulations differ in regard to physical characteristics, dosing, and strength of evidence for efficacy. Whether there are any differences in absorption and mechanism of action between the 2 formulations is currently unknown. Optimal dosing, efficacy, and safety have been established for SLIT-T. In contrast, in North America there is little support for efficacy of SLIT-D from randomized double-blind, placebo-controlled trials, and dose ranges have not been appropriately evaluated. SLIT-T treats a single allergen, whereas in the United States SLIT-D often contains multiple allergens to treat polysensitization. The safety profiles of SLIT-T and SLIT-D appear similar, and both formulations are considered safer than SCIT.

CONCLUSION

Professional guidelines should make a clear distinction between SLIT-T and SLIT-D in their recommendations to minimize confusion with the umbrella term SLIT.

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.

[Allergen-derived peptide: A promising approach in asthma]

Severe asthma required high dose of corticosteroids combined with biotherapies to control more or less asthma symptoms and lead to the decrease of patients' quality of life on long term. Recent studies show that hypoallergenic peptides derived from allergen can prevent airway hyperresponsiveness, decrease Th2 response and also allergen-specific IgE in mouse models of allergic asthma. Even if some peptides mechanisms remain unknown, their fast efficacy with low doses of allergens make peptide immunotherapy a new promising approach in allergic asthma.

Sublingual allergen immunotherapy for respiratory allergy: a systematic review

The objective of the systematic review is to provide complete and updated information on efficacy and safety of sublingual immunotherapy (SLIT) formulations for the treatment of allergic respiratory diseases (ARDs). The literature search was conducted on PubMed database, involving double-blind, randomized clinical trials published between January 1992 and 2018, written in English, and performed in humans. The number of articles finally selected for review was 112. Data from the majority of properly controlled clinical trials demonstrate that SLIT is effective not only with short-term use (first year) but also with long-term use (up to the third year of active therapy), for treating ARDs in children and adults. Both continuous and discontinuous schemes of administration showed significant reductions in symptom and medication scores. Moreover, a SLIT-induced disease-modifying effect has been documented mainly with grass pollen extracts, since improvement is maintained during at least 2 years of follow-up after a 3-year treatment period. Additionally, allergen immunotherapy should also be considered a preventive strategy, especially for decreasing bronchial asthma incidence in children and adolescents with allergic rhinitis treated with SLIT. This therapy is also safe, producing only a few mainly local and mild-to-moderate adverse events, and usually self-limited in time. The registration and authorization of allergen SLIT preparations (grasses and house-dust mite tablets) as drugs by regulatory agencies, such as the United States Food and Drug Administration (FDA) and the European Medicines Agency (EMA), has represented a landmark in allergy immunotherapy research. Further long-term studies, specially designed with allergens other than grass pollen or house-dust mites, not only in allergic rhinoconjunctivitis but also on asthmatic subjects, as well as studies comparing different administration schedules and/or routes, are required in order to continue the progress in the modern development of this particularly promising therapy.

The global development and clinical efficacy of sublingual tablet immunotherapy for allergic diseases

Allergy immunotherapy (AIT) is a treatment option for respiratory allergy that is complementary to pharmacotherapy, with a distinct mechanism of action. Alternative methods to subcutaneous administration of AIT that enable patients to safely self-administer AIT is considered an unmet clinical need. The sublingual immunotherapy tablet (SLIT-tablet) is an orally disintegrating pharmaceutical formulation (oral lyophilisate) containing standardized allergens. SLIT-tablets have been developed for sublingual immunotherapy (SLIT) of cedar-pollen, grass-pollen, ragweed-pollen, tree-pollen, and house dust mite allergies. It is a once-daily tablet treatment to be self-administered after the first dose has been provided under the supervision of a physician with experience in the diagnosis and treatment of allergic diseases. Once the first dose is adequately tolerated, subsequent doses may be self-administered. SLIT-tablets have proven efficacy for allergic rhinitis (AR) with and without conjunctivitis (C) and allergic asthma (AA) in adults, children, and poly-sensitized allergic patients. Meta-analyses indicate that SLIT-tablets have superior or similar efficacy compared with anti-allergic pharmacotherapies for seasonal AR and superior efficacy for perennial AR. SLIT-tablets have also demonstrated clinically relevant improvements of asthma, with significant reductions in the following: daily inhaled corticosteroid use, risk of asthma exacerbations, and asthma symptoms. SLIT-tablets are generally well tolerated, with a low risk of systemic allergic reactions. The most common treatment-related adverse events are mild-moderate oral reactions. Current evidence supports SLIT-tablets to be considered as an alternative or add-on treatment to pharmacotherapy for AR/C and asthma. Future SLIT developments may include early intervention to prevent the development or progression of allergic disease in children.

Ragweed sublingual tablet immunotherapy: part II - practical considerations and pertinent issues

Sublingual allergen immunotherapy (SLIT) has been demonstrated to be both efficacious and safe for the treatment of respiratory allergies such as allergic rhinoconjunctivitis or allergic asthma. Based on the clinical documentation of SLIT ragweed tablets, they have gained marketing authorization in the USA by the US FDA in 2014 for adult patients. Following clinical data from (pivotal) multicenter Phase II and III trials as performed in the USA and Canada and real life experience after registration in 2014, SLIT ragweed tablets can be recommended as efficacious and safe treatment option with disease modifying potential when adequately indicated and performed. Therefore, several practical issues should be considered for treating ragweed allergic patients with these tablets. This second part of a thorough review on ragweed SLIT tablets addresses important clinical questions which should be taken into account by the subscribing practitioner before initiation and during the treatment.

SQ house dust mite sublingual immunotherapy tablet subgroup efficacy and local application site reaction duration

BACKGROUND

Allergic rhinitis with or without conjunctivitis (AR/C) is common, necessitating evaluation of SQ house dust mite (HDM) sublingual immunotherapy (SLIT)-tablet efficacy in various subgroups.

OBJECTIVE

To evaluate 12 SQ-HDM efficacy and safety across subgroups, and the onset, duration, and recurrence of local application site reactions.

METHODS

Subgroup (age, sex, race, asthma status, and allergen sensitization) efficacy was assessed using pooled data from 2 previously described trials of daily 12 SQ-HDM vs placebo for AR/C (n = 2,138). Efficacy was measured by average total combined rhinitis score (TCRS; rhinitis daily symptom plus medication score) during the last 8 weeks of treatment. Safety in subgroups and local application site reaction onset, duration, and recurrence were evaluated using pooled data from 5 previously described trials of SQ HDM SLIT-tablet (n = 2,923).

RESULTS

Significant (based on 95% confidence intervals [CIs]) reduction in TCRS was seen with 12 SQ-HDM relative to placebo across all subgroups, with TCRS improvements ranging from 15% to 25%. The AE profile was generally similar within subgroups. Approximately 95% of local application site reactions were mild to moderate in severity. Median duration on day 1 of treatment for the most common local application site reactions (throat irritation, oral pruritus, ear pruritus, and lip swelling) ranged from 30 to 60 minutes; median first day of onset ranged from days 1 to 4 of treatment; median days that reactions recurred ranged from 3 to 12 days.

CONCLUSION

Treatment with 12 SQ-HDM consistently improved symptoms and was well tolerated in relevant subgroups of subjects with HDM AR/C. Local application site reactions to 12 SQ-HDM were typically mild to moderate and transient.