Real-world surveillance of standardized quality (SQ) house dust mite sublingual immunotherapy tablets for 3 years in Japan

<b>Background:</b> Standardized quality (SQ) house-dust mite (HDM) sublingual immunotherapy tablets (10,000 Japanese allergy units [JAU], equivalent to 6 SQ-HDM in Europe and the United States) are licensed for the treatment of HDM-induced allergic rhinitis (AR) without age restriction, based on 52-week administration clinical trials. There are no large-scale data on the administration of 10,000 JAU for > 1 year in actual clinical practice. <b>Objective:</b> To examine the safety and effectiveness of 10,000 JAU during use for up to 3 years at real-world clinical sites in Japan. <b>Methods:</b> This survey was a multicenter, observational, prospective study. We assessed the safety and effectiveness of the long-term administration of 10,000 JAU as well as effectiveness after its discontinuation in patients with HDM AR with an observation period of 3 years. <b>Results:</b> The safety analysis included 815 patients, and the effectiveness analysis included 768 patients. Adverse reactions that occurred in 144 patients (17.67%) were mainly site-related events that occurred early in the dosing period. Serious adverse reactions were dyspnea and anaphylactic reaction in one patient each, and both patients recovered. With regard to effectiveness, compared with scores before the administration of SQ-HDM, nasal symptom scores decreased, depending on the administration period, from 6 months to 3 years. Overall, 67.34% of the patients had improved quality of life after 6 months, and this improvement continued after 12 months. The proportion of patients with "improved and slightly improved" of overall improvement exceeded 90% after 2 years. Treatment discontinuation because "symptoms disappeared" occurred in 24.42% of the patients at 3 years. Patients who discontinued 10,000 JAU (<i>n</i> = 39) had a sustained improvement in nasal symptom scores compared with baseline, even 1 year after discontinuing treatment. <b>Conclusion:</b> The real-world safety and effectiveness of 10,000 JAU SQ-HDM sublingual immunotherapy tablets were confirmed in Japanese patients with HDM AR. No new safety and effectiveness precautions were required.