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

Focused allergic rhinitis practice parameter for Canada

Allergic rhinitis (AR) is a prevalent disease in Canada that affects both children and adults. Several guidelines for the management of AR have been published by professional allergy societies worldwide. However, there are regional differences in the clinical management of AR, and regulatory approval of some AR pharmacotherapies varies among countries. Thus, six research questions specific to the treatment of AR in Canada were identified for this focused practice parameter. Reviews of the literature published since 2016 were conducted to obtain evidence-based support for the responses of the Work Group to each research question. In response to research question 1 "In patients with symptoms indicative of AR, is serum-specific IgE sufficient to identify candidates for immunotherapy or is a skin prick test mandatory?" the Work Group concluded that either sIgE testing or skin prick test are acceptable for diagnosing AR and guiding immunotherapy. In response to research question 2 "When taking into account the preferences of the patient and the prescriber (stakeholder engagement) should second-generation oral antihistamine (OAH) or intranasal corticosteroid (INCS) be first line?" the Work Group concluded that existing guidelines generally agree on the use of INCS as a first-line therapy used for AR, however, patient and provider preferences and considerations can easily shift the first choice to a second-generation OAH. In response to research question 3 "Is a combination intranasal antihistamine (INAH)/INCS formulation superior to INCS plus OAH? Do they become equivalent after prolonged use?" the Work Group concluded that that the combination INAH/INCS is superior to an INCS plus OAH. However, there was insufficient evidence to answer the second question. In response to research question 4 "Do leukotriene receptor antagonists (LTRA) have a greater benefit than OAH in AR for some symptoms to justify a therapeutic trial in those who cannot tolerate INCS?" the Work Group concluded that LTRAs have inferior, or at best equivalent, daytime or overall symptom control compared with OAH, but LTRAs may improve nighttime symptom control and provide benefits in patients with AR and concomitant asthma. In response to research question 5 "Should sublingual immunotherapy (SLIT) tablets be considered first-line immunotherapeutic options over subcutaneous immunotherapy (SCIT) based on the evidence of efficacy?" the Work Group concluded that the choice of SLIT or SCIT cannot be made on efficacy alone, and differences in other factors outweigh any differences in efficacy. In response to research question 6 "Based on efficacy data, should ALL patients seen by an allergist be offered SLIT or SCIT as a treatment option?" the Work Group concluded that the efficacy data suggests that SLIT or SCIT should be used broadly in patients with AR, but other clinical concerns also need to be taken into consideration.

SQ sublingual immunotherapy tablets for children with allergic rhinitis: A review of phase three trials

AIM

To provide paediatricians with a summary of efficacy and safety of SQ sublingual immunotherapy (SLIT) tablets from phase three, randomised, double-blind, placebo-controlled trials in children and adolescents with allergic rhinitis or rhinoconjunctivitis, with and without asthma.

METHODS

PubMed searches were conducted and unpublished data were included if necessary.

RESULTS

Of the 93 publications, 12 were identified reporting 10 trials. One trial was excluded as paediatric-specific efficacy data were unavailable. The nine eligible trials evaluated grass, house dust mite, ragweed and tree SLIT tablets. Consistent reductions in allergic rhinitis or rhinoconjunctivitis symptoms and medication use were observed with SQ SLIT tablets versus placebo. In a five-year trial, sustained reduction of allergic rhinoconjunctivitis symptoms, asthma symptoms and medication use were observed with SQ grass SLIT tablet versus placebo. The number-needed-to-treat to prevent asthma symptoms and medication use in one additional child during follow-up was lowest in younger children. SQ SLIT tablets were generally well tolerated across trials.

CONCLUSION

Evidence supports use of SQ SLIT tablets in children and adolescents with allergic rhinitis or rhinoconjunctivitis, with and without asthma. Long-term data demonstrate disease-modifying effects of SQ grass SLIT tablet and suggest the clinical relevance of initiating allergy immunotherapy earlier in the disease course.

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.

Tablet allergen immunotherapy: the anaphylaxis issue

For the first time 15 years ago, tablet allergen immunotherapy (T-AIT) formulations were approved by regulatory agencies for treating allergic rhinitis caused by grass pollen in adults and children aged >5 years. Extensive evidences existed about effectiveness and safety of AIT. However, the safety profile is particularly compelling in children. Generally, T-AIT causes local reactions, mostly in the oral cavity, that are usually mild-to-moderate and often self-resolving. However, systemic allergic reactions are also observed with T-AIT, anaphylaxis representing the most fearsome adverse event, considering that it occurs in subjects treated for allergic rhinitis. Therefore, we conducted a literature search of patients reporting anaphylaxis because of T-AIT. Nine cases of anaphylactic reactions were reported in literature. Notably, no death was reported using T-AIT. This outcome was very important as it underscored the substantial safety of T-AIT. However, T-AIT deserves careful attention, mainly in the pediatric population. In this regard, after the first report of anaphylactic reaction at the first administration of T-AIT, manufacturers recommended that the first dose should be administered in a medical facility in the presence of staff with experience in managing anaphylaxis and the patient should be observed for at least 30 min. Interestingly, reported anaphylactic reactions were due to grass pollen extracts, with no report concerning other allergen extracts. However, it is relevant to note that anaphylactic reactions because of T-AIT are not reported in recent years.

Safety of allergen immunotherapy in children

PURPOSE OF REVIEW

The current review discusses allergen immunotherapy (AIT) safety in children.

RECENT FINDINGS

AIT is a well tolerated and effective treatment for pediatric allergic conditions. While mostly well tolerated, severe reactions and near fatal reactions may occur with subcutaneous immunotherapy (SCIT) once in every 160 000 visits. Sublingual immunotherapy (SLIT) is associated more with local side effects, but severe systemic reactions, including anaphylaxis, have been rarely reported. Providing informed consent, recognizing risk factors for severe systemic reactions, such as severe or uncontrolled asthma, and mitigating the risk of severe reactions are important components to improving the safety of AIT.

SUMMARY

Overall, AIT is well tolerated in children, and data suggest that the incidence of systemic reactions in children receiving SCIT is no less than mixed populations of adult and pediatric patients. SLIT carries less risk for systemic reactions, and local oral site-application reactions are usually mild and resolve within 15 days of treatment.

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.

Pediatric sublingual allergen immunotherapy

Sublingual immunotherapy (SLIT) offers an important therapeutic modality in the management of children with respiratory allergies. Along with subcutaneous immunotherapy, these modalities are the only selections that have shown not merely relief of symptoms but also disease-modifying activity. SLIT can be given as either a dissolvable tablet (SLIT-T) or liquid drops (SLIT-D). In studies that examined the efficacy and safety in allergic rhinitis and asthma, SLIT-T and SLIT-D both show efficacy in reducing symptoms and the need for medication, although it seems that SLIT-T may show a better response. Almost all SLIT-D efficacy studies are with single allergens. There are virtually no data on the efficacy of mixing unrelated allergens in the same prescription. Both SLIT-T and SLIT-D treatments are safe, with the most common adverse effects being local ones, such as oral pruritus and mouth irritation, which tend to be mild and short lived. Studies that assess the role of SLIT in the prevention of new sensitizations and asthma in the pediatric population are insufficient and of mixed results; therefore, no conclusions can be made. In the treatment of other pediatric conditions, such as food allergy and atopic dermatitis, there are few studies that assessed if, and the degree of, the benefit with SLIT. In determining if SLIT should be prescribed for the pediatric patient, there is a need for shared decision-making to allow the older child and parents or caregivers to understand the pros and cons, and the costs of all the options and relate their values and preferences to the physician.

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.

Preventive Effect of Allergen Immunotherapy on Asthma and New Sensitizations

Allergen immunotherapy (AIT) is a disease-modifying treatment for some IgE-mediated allergic diseases with the potential to have important preventive effects. Children with allergic rhinitis have a high risk of developing asthma, and treating allergic rhinitis with AIT may interfere with disease progression and prevent onset of asthma. Although the evidence is limited due to relatively few and heterogeneous studies, data nevertheless suggest that AIT has a preventive effect on development of asthma especially in children with rhinitis due to grass pollen allergy. AIT may also affect the development of new sensitizations. Both the degree of sensitization and the specific sensitization pattern may influence future disease severity and development of comorbidities. Hitherto, the indication for AIT for prevention of development of asthma in grass/birch pollen allergic children has been the same as for treatment of allergic rhinitis. Probably, AIT should be applied in the early stage of the allergic disease to have the greatest preventive effect on disease progression. Consequently, in the future, the potential preventive effects should influence the timing of initiating AIT. The window of opportunity to prevent asthma may primarily exist in young children with mild symptoms and a low degree of sensitization.

Current and emerging pharmacotherapy for pediatric allergic rhinitis

INTRODUCTION

Allergic rhinitis (AR) is a global health problem in adults as well as the younger population, continuously increasing and posing a significant problem for patients, health care systems and economies. For the younger population, some aspects differ from treatment of adults, namely, prevention, compliance and adherence.

AREAS COVERED

This narrative review summarizes all the pharmacotherapeutic options with special focus on the pediatric population. Moreover, it elucidates prevention strategies as well as future developments of AR treatment. Currently, symptomatic therapy in the form of steroids and antihistamines is applied topically and systemically where steroids need to be administered with caution and for a very short term. The only disease-modifying and causal treatment is allergen immunotherapy administered sublingually and subcutaneously. Future and current novel therapeutic options are human monoclonal antibodies.

EXPERT OPINION

The greatest potential for future developments currently lie in allergen immunotherapy and here in different routes of administration and modification of (recombinant) allergens as well as immune-modulating adjuvants and nanoparticles. Secondly, monoclonal antibodies are promising molecules blocking and/or interfering with up- and downstream immune mechanisms. Another important aspect lies in prevention of allergic sensitization and disease progression through both AIT and biologics which is particularly true for the pediatric population.

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.