Patient selection in a house dust mite allergy immunotherapy asthma trial
Published online: September 18, 2019
The Global Initiative for Asthma (GINA) global strategy for asthma management and prevention has adopted sublingual immunotherapy (SLIT) as an add-on treatment option for allergic asthma in adult individuals with allergic rhinitis who are sensitized to house dust mite (HDM). GINA adopted SLIT as an option based on the results of the clinical trials of standardized quality (SQ) HDM SLIT tablets conducted in Europe. Allergy immunotherapy and SLIT are also established in Japan to treat allergic respiratory diseases, mainly allergic rhinitis caused by Japanese cedar and HDM.
In an original article recently published in The Journal of Allergy and Clinical Immunology: In Practice, Tanaka and colleagues conducted a double-blind, placebo-controlled clinical trial that aimed to confirm the efficacy and safety of the SQ HDM SLIT tablet in more than 800 Japanese adults with allergic asthma. The primary endpoint of the trial was the time from randomization to the first moderate or severe asthma exacerbation as the inhaled corticosteroid dose was being reduced.
The trial did not meet its primary or any other efficacy endpoints. However, based on the results of post hoc analyses, the authors found that the control level of asthma symptoms of randomized individuals in the baseline period was critical for the efficacy outcome of this trial design. The post hoc analyses of the sub-population with asthma symptoms that required short-acting beta-2 agonists (SABAs) in the baseline period revealed that the risk of asthma exacerbation in the SQ HDM SLIT tablet group was reduced to a clinically meaningful degree (hazard ratio = 0.70, P = .04997) as defined in the European trial. The SQ HDM SLIT tablet exhibited a favorable safety profile.
The authors concluded that these outcomes suggest that the SQ HDM SLIT tablet is safe overall, and also effective in a subset of the Japanese individuals with HDM allergic asthma requiring SABAs in the baseline period. The results support the relevance of the treatment in ethnically diverse populations with HDM allergic asthma.
The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.