Subcutaneous Immunotherapy Shows Promise for Allergic Asthma Exacerbations

The use of subcutaneous immunotherapy (SCIT) has demonstrated efficacy in children with moderate to severe allergic asthma exacerbations, but a thorough assessment of the benefit-to-risk ratio and the patient’s health status is needed, according to the results of a retrospective study conducted in the Allergology Department of a tertiary care center in Paris, France, published in Annals of Allergy, Asthma & Immunology.¹

The files of children aged 6 to 18 years who received cluster SCIT for a documented Dermatophagoides pteronyssinus allergic episode between 1990 and 2016 were screened. Children with moderate to severe asthma based on Global Initiative for Asthma (GINA)² criteria were included for analysis. There was no SCIT performed concurrently for any other allergens.

Trained staff administered injections after checking asthma control during the previous 4 weeks. Cluster SCIT included a build-up phase of 1 cluster day per month for 4 months (cumulative dose of D pteronyssinus: 0.6 to 10 μg of IRIS^® [ALK-Abelló; Varennes-en-Argonne, France]). During this phase, between 4 and 8 subcutaneous injections were administered in a single day at 20-minute intervals. This build-up phase was followed by a maintenance phase, in which 1 monthly injection of D pteronyssinus was administered.

Gender, age, history of allergic rhinitis or atopic dermatitis, and parental history of asthma were obtained. Sensitization to any aeroallergens was defined by a specific
immunoglobulin E (IgE) ≥0.35 kU/L.

Overall, 56% of the children analyzed experienced ≥1 adverse reaction while undergoing SCIT, which accounted for 73 adverse reactions (2% of the 3455 performed injections). Moreover, 33% of the children experienced multiple reactions, and 22% experienced a systemic reaction, which accounted for 0.5% of all injections administered. Of children who experienced a systemic reaction, 3% experienced a grade 1 systemic reaction, 19% experienced a grade 2 systemic reaction, and 1 patient experienced a grade 3 systemic reaction that required the use of epinephrine.

A majority of the adverse reactions experienced by the children (89%; 65 of 73 adverse reactions) were recorded during the build-up phase. Furthermore, all of the grade 2 and grade 3 SRs occurred during the build-up phase and resulted in SCIT discontinuation in all patients.

During the maintenance phase, approximately 20% of the children discontinued SCIT — 8% because of uncontrolled asthma, 4% as a result of repeated bothersome local reactions, 7% because of a lack of compliance, and 1% because of a change in living location.

The mean rate of asthma exacerbations declined significantly from 2.1±4.5 to 0.38±0.68 after 1 year of SCIT (P <.001) and to 0.44±0.58 after 3 years (P = .01). The average dose of equivalent of fluticasone propionate (EFP) used decreased significantly from 500 μg/d (range, 375 to 800 μg/d) after 1 year (P <.001) and to 200 μg/d (range, 200-400 μg/d) after 3 years of SCIT (P =.01).

The investigators concluded that the use of SCIT is associated with an early decrease in severe exacerbations of asthma, despite a reduction in EFP dose used, in a pediatric population. A prospective, randomized, placebo-controlled trial is warranted to confirm these results.

Disclosures: ALK-Abelló provided funding for this research.

References

1. Amat F, Sese L, Hayat M, Bourgoin-Heck M, Just J. Subcutaneous allergen immunotherapy may be a suitable treatment for exacerbator allergic asthma [published online May 24, 2018]. Ann Allergy Asthma Immunol. doi: 10.1016/j.anai.2018.05.021
2. Global Initiative for Asthma (GINA) Report. Global Strategy for Asthma Management and Prevention 2017. www.ginasthma.org. Accessed July 11, 2017.