Safety profile of the SQ house dust mite sublingual immunotherapy-tablet in Japanese adult patients with house dust mite-induced allergic asthma: a randomized, double-blind, placebo-controlled phase I study

Objective: The SQ house dust mite (HDM) sublingual immunotherapy (SLIT)-tablet has demonstrated effective treatment of HDM-induced allergic asthma in patients 18?years or older in European trials. This study investigated its safety and immunology profile in Japanese adult patients with mild-to-moderate HDM-induced allergic asthma. Methods: In this randomized, double-blind, placebo-controlled study, 48 Japanese patients were randomly assigned to a daily treatment of SQ HDM SLIT-tablet or placebo (3:1) for 14?d with or without an up-dosing regimen. Active groups comprised 5000, 10,000 or 20,000 Japanese Allergy Unit (JAU) for 14 d, and the up-dosing group comprised 5,000 JAU in day 1?3, 10,000 JAU in day 4?7 and 20,000 JAU in day 8?14. Results: No marked differences were observed in the incidence rate of adverse events (AEs) and their severity among active groups. The five most common investigational medicinal product (IMP)-related AEs were local events at the application site observed within 30?min after the intake of the SQ HDM SLIT-tablet. Although most events recovered within 1?h, mouth edema indicated a different profile of duration with more than 25% of the events lasting for more than 1?h. Conclusions: The SQ HDM SLIT-tablet of up to 20,000 JAU was well tolerated, and safety profile was acceptable for Japanese subjects with HDM-induced allergic asthma.