ABSTRACT Background Japanese cedar (JC) pollen sublingual immunotherapy (SLIT)‐tablets (5000 Japanese allergy units JAU) are licensed for the treatment of JC‐pollinosis with no age restriction on the basis of the results of a 5‐year clinical trial. However, there have been no large‐scale surveys of 5000 JAU in an actual clinical setting. Methods This was a multicenter observational prospective study. We assessed the safety and effectiveness of the long‐term use of 5000 JAU in patients with JC‐pollinosis, with an observation period of two seasons of JC pollen dispersal, at clinical sites in Japan. Results Our safety analysis included 516 patients and the effectiveness analysis included 469 patients. Adverse drug reactions (ADRs) occurred in 68 patients (13.18%) and mainly comprised administration site‐related events that occurred during the early phase of administration. Treatment discontinuation due to ADRs occurred in 18 patients (3.49%). No deaths, anaphylactic shock, or serious ADRs occurred. Regarding effectiveness, the severity of JC‐pollinosis was rated as “almost asymptomatic + mild” in 82.19% of patients in Season 1 and 92.58% in Season 2. Quality of life was rated as “score 0 (Fine) + 1” in 75.83% of patients in Season 1 and 86.09% in Season 2. Overall improvement was rated as “improved + slightly improved” in 95.68% of patients in Season 1 and 96.38% in Season 2 following the initiation of JC pollen SLIT‐tablets. Nasal and ocular symptom scores also decreased with increasing treatment duration. Treatment continuation rates were 89.53% in Season 1 and 78.29% in Season 2. Conclusion The JC pollen SLIT‐tablets appear to be safe and effective in an actual clinical setting during two seasons. No new safety or effectiveness issues were identified, and no additional safety or effectiveness precautions were required.
Gotoh et al. (2026) studied this question.