Background: The German Therapy Allergen Ordinance (TAO) triggered an ongoing upheaval in the market for house dust mite (HDM) allergen immunotherapy (AIT) products. Three HDM subcutaneous AIT (SCIT) products hold approval in Germany and therefore will be available after the scheduled completion of the TAO procedure in 2026. In general, data from clinical trials on the long-term effectiveness of HDM AIT are rare. We evaluated real-world data (RWD) in a retrospective, observational cohort study based on a longitudinal claims database including 60% of all German statutory healthcare prescriptions to show the long-term effectiveness of one of these products in daily life. Methods: Subjects between 5 to 70 years receiving their first (index) prescription of SCIT with a native HDM product (SCIT group) between 2009 and 2013 were included. The exactly 3:1 matched control group received prescriptions for only symptomatic AR medication (non-AIT group); the evaluation period for up to 6 years of follow-up ended in February 2017. Study endpoints were the progression of allergic rhinitis (AR) and asthma, asthma occurrence and time to the onset of asthma after at least 2 treatment years. Results: 892 subjects (608 adults, 284 children/adolescents) were included in the SCIT group and 2676 subjects (1824 adults, 852 children/adolescents) in the non-AIT group. During the follow-up period after at least two years of SCIT, the number of prescriptions in the SCIT group was reduced by 62.8% (p<0.0001) for AR medication and by 42.4% for asthma medication (p=0.0003). New‐onset asthma risk was significantly reduced in the SCIT vs non‐AIT group by 27.0% (p=0.0212). The asthma preventive effect of SCIT occurred 15 months after start of the treatment. In the SCIT group, the time to onset of asthma was reduced compared to the non-AIT group (p=0.0010). Conclusion: In this RWD analysis patients aged between 5 to 70 years benefited from SCIT with a native HDM product in terms of the reduced progression of AR and asthma after at least 2 years of treatment in the long term. The effects lasted for up to six years after treatment termination. A significantly reduced risk of asthma onset was observed, starting after 15 months of treatment.

Background: Randomized controlled trials (RCTs) are the gold-standard for benefit-risk assessments during drug approval processes. Real-word data (RWD) and the resulting real-world evidence (RWE) are becoming increasingly important for assessing the effectiveness of drug products after marketing authorization showing how RCT results are transferred into real life care. The effectiveness of allergen immunotherapy (AIT) has been assessed in several RWE studies based on large prescription databases. Methods: We performed a literature search for retrospective cohort assessments of prescription databases in Europe to provide an overview on the methodology, long-term effectiveness outcomes and adherence to AIT. Results: 13 respective publications were selected. AIT was more effective in reducing the progression of allergic rhinitis (AR) compared to a non-AIT control group receiving only symptomatic treatment for AR for up to 6 years. The development and progression of asthma was hampered for most endpoints in patients treated with most preparations compared to the non-AIT group, receiving only anti-asthmatic medication. The results for “time to onset” of asthma were inconsistent. Adherence to AIT decreased during the recommended 3-years treatment period, however in most studies higher adherence to subcutaneous than to sublingual AIT was shown. Conclusion: The analysis of long-term effectiveness outcomes of the RWE studies based on prescription databases confirms the long-term efficacy of AIT demonstrated in RCTs. Progression of rhinitis and asthma symptoms as well as delayed onset of asthma triggered by different allergens, real life adherence to the treatment shows differences in particular application routes.