Efficacy of sublingual immunotherapy for cedar pollinosis: A systematic review and meta-analysis

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.

Effectiveness of sublingual immunotherapy in pediatric cedar pollinosis: A real-world database study

BACKGROUND

Pediatric allergic rhinitis (AR), including cedar pollinosis (CP), is increasing in Japan. We investigated the effects of sublingual immunotherapy (SLIT), which has limited studies of its effectiveness in real-world settings, on children with CP.

METHODS

This retrospective cohort study used a claim database in 2018-2021. Children aged ≤15 years with CP records in 2019 were eligible and were followed up through 2021. We included 2962 CP children undergoing SLIT and 547 who were not. The medication score was used to evaluate SLIT effectiveness in the cedar pollen dispersal season each year. Adverse events and the occurrence of allergic diseases were also evaluated.

RESULTS

Medication score was higher in the SLIT group during the index period but lower in 2021 compared to the non-SLIT group (mean ± standard deviation: 5.17 ± 2.39 and 4.74 ± 2.38 in 2019, 3.13 ± 2.30 and 3.55 ± 2.48 in 2021, respectively). The adjusted mean difference between groups from 2019 to 2021 was -0.62 (95% confidence interval: -0.86 to -0.39, p < .0001), and the medication score was reduced in the SLIT group (risk ratio: 1.2: 1.1 to 1.3). The occurrence of adverse events involving abdominal disorders (adjusted odds ratio [aOR]: 0.64: 0.51 to 0.81), asthma exacerbation (aOR: 0.37: 0.24 to 0.57), and allergic diseases involving hay fever unrelated to CP (aOR: 0.60: 0.45 to 0.80) or asthma (aOR: 0.71: 0.58 to 0.86) was lower in the SLIT group.

CONCLUSION

In children with CP, SLIT is effective, well tolerated, and could decrease the occurrence of other allergic diseases.

Artemisia Annua sublingual immunotherapy for seasonal allergic rhinitis: A multicenter, randomized trial

Background

Artemisia annua is the most common outdoor aeroallergen throughout Northern China; however, no multicenter study has investigated sublingual immunotherapy (SLIT) as a treatment option for Artemisia annua-induced allergic rhinitis (AR). The aim of this study was to evaluate the efficacy and safety of an innovative SLIT for Artemisia annua-related AR.

Methods

This was a randomized, double-blind, placebo-controlled, multicenter, phase 3 clinical trial conducted in China (NCT XXX). A total of 702 Artemisia annua-sensitized eligible patients were randomized in a ratio of 2:1 to receive Artemisia annua-SLIT or placebo. The treatment lasted 32 weeks; including 5-weeks up-dosing phase and 27-weeks maintenance phase. The primary endpoint was the daily combined score of medication and rhinoconjunctivitis symptom (CSMRS), and secondary endpoints were daily total nasal symptom score (dTNSS) and daily rescue medication score (dRMS) during peak pollen period. Safety of treatment was evaluated according to adverse events (AEs) experienced.

Results

Mean daily CSMRS was significantly improved during the peak pollen period in the SLIT group compared with the placebo group (1.46 ± 0.47 vs 1.88 ± 0.42, P < 0.0001 in full analysis set [FAS]; 1.49 ± 0.52 vs 1.95 ± 0.46, P < 0.0001 in per protocol set [PPS]); representing a 22.3% and 23.6% reduction, respectively, relative to placebo. In specifically Artemisia annua monosensitized patients, mean daily CSMRS reductions were demonstrated as 24.1% and 27.0% in the FAS and PPS populations, respectively, when comparing the active treatment to placebo treatment. Similarly, SLIT decreased dTNSS in peak pollen period by 19.0% in FAS and 22.3% in PPS, respectively, relative to placebo. In coincidence, dRMS in peak pollen period was reduced by 22.0% in FAS and 26.0% in PPS. 65.8% patients in SLIT group experienced treatment-related AEs, none of which was serious.

Conclusion

This study indicates that SLIT with Artemisia annua drops is an effective and safe treatment option in Chinese patients with Artemisia Annua-induced AR.

Principles of Allergen Immunotherapy and Its Clinical Application in China: Contrasts and Comparisons with the USA

Allergen immunotherapy (AIT) for allergic rhinitis (AR), asthma, and other allergic diseases has developed quickly. House dust mite (HDM), Artemisia (wormwood), Humulus japonicus (Japanese hop), Alternaria alternata, and Cladosporium herbarum are the five most common inhalant allergens in China. AIT has been performed in China for over 60 years. With the support of the Chinese Medical Association (CMA) and the Chinese Medical Doctors Association (CMDA), the Chinese College of Allergy and Asthma (CCAA) was established in 2016 as a specialized branch of CDMA and is the main certification authority for AIT. Chinese allergists and scientists have made tremendous progress in the development of AIT. There have been many publications by Chinese allergists and scientists worldwide encompassing original research studies, systematic reviews, case studies, and clinical trials. Currently, conventional subcutaneous immunotherapy (SCIT) is the preferred AIT in China, but sublingual immunotherapy (SLIT) is beginning to gain recognition. An increasing number of clinical trials have been conducted to investigate the clinical efficacy and side effects of SLIT and SCIT. In China, HDM is the only commercial standardized allergen extracts in clinical use, whereas the others are crude allergen extracts. Besides standardized allergen extracts, other forms of hypoallergenic extracts are still being investigated and developed in China. Immunotherapy in China is similar to that in the USA in which allergen extracts can be mixed for SCIT. However, allergen extracts cannot be mixed for SCIT in Europe.

Effects of a Cloth Panel Containing a Specific Ore Powder on Patients with Japanese Cedar Pollen Allergy During the Pollen Dispersal Season

Pollen allergy remains a big problem in contemporary societies. We have shown in previous studies that a cloth containing a special natural ore powder (CCSNOP) is effective in relieving symptoms in patients with pollen allergies. However, in that study, subjects were exposed to CCSNOP for only one hour. In the present study, CCSNOP or control (non-woven cloth; NWC) panels were placed in the bedrooms of pollen allergy patients for two weeks during the pollen dispersal season in 2018, and the effects were investigated. Twenty-one subjects were exposed to CCSNOP panels and 10 subjects were exposed to NWC panels. Our investigations showed that use of CCSNOP resulted in relief of symptoms and reduced use of therapeutics. Moreover, the ratio of eosinophil count decrease during exposure was higher in the CCSNOP group. Furthermore, a formula for measuring various cytokines and other parameters was established and clearly showed a distinction between the CCSNOP and NWC groups. In this formula, Granulocyte Macrophage colony-stimulating Factor (GM-SCF), Interleukin (IL)-12p40, Immunoglobulin (Ig) G4 and eosinophil count were extracted. These results indicated that CCNSNOP has a beneficial effect on pollen allergy patients. Future studies shall engage in long-term monitoring of pollen allergy patients who will utilize this mineral powder for at least one year.

Allergen immunotherapy for the treatment of allergic rhinitis and/or asthma: an umbrella review

BACKGROUND

Allergic rhinitis and asthma are important public health concerns, yet there is no consensus about the benefits and harms of allergen-specific immunotherapy to treat these conditions. We performed an umbrella review of systematic reviews summarizing the current evidence for the benefits and harms of subcutaneous immunotherapy (SCIT) and sublingual immunotherapy (SLIT).

METHODS

We searched MEDLINE, Embase, the Cochrane Library and the grey literature from Jan. 1, 2010 to Nov. 20, 2016 for systematic reviews of randomized controlled trials or prospectively controlled studies involving children or adults with allergic rhinitis or asthma. Outcomes were summarized narratively (benefits: total combined symptom-medication score, symptom score, medication score, disease-specific quality of life, adherence; harms: anaphylaxis, death, local and systemic reactions).

RESULTS

Twenty-three systematic reviews were included. SCIT and SLIT were more effective than placebo for most outcomes. SCIT was better than SLIT at improving medication and symptom scores, with no differences in quality of life; however, data were limited for this comparison. Anaphylaxis and death were infrequently reported. Few reviews assessed benefits or harms among children.

INTERPRETATION

Allergen immunotherapy appears to be effective among patients with allergic rhinitis and asthma. The safety of allergen immunotherapy is not conclusively established, although death and anaphylaxis appear to be rare. PROSPERO no.: CRD42015024590.