D2.221 - Exploring the effect of HDM SLIT-tablets on atopic dermatitis prescriptions in patients with pre-existing atopic dermatitis: Results from the Real-world Evidence of house dust Mite Immunotherapy Tablets (REMIT) study

Allergic rhinitis (AR) and atopic dermatitis (AD) are highly prevalent inflammatory diseases frequently coexisting across the life course. The conditions are suspected to be linked via the atopic march, with overlapping allergen sensitisation and shared type 2 immune pathways. Given the frequent coexistence of AR and AD, and the potential for systemic immunomodulation by allergy immunotherapy (AIT), an exploratory objective of the REMIT study was to assess whether treatment with 6 SQ house dust mite sublingual immunotherapy tablets (SQ HDM SLIT-t) could be associated with reduced AD prescriptions (AD Rx).

The REMIT study was a predefined, retrospective cohort study (2015–2023) using propensity score matching (1:1) to evaluate the long-term effectiveness of SQ HDM SLIT-t treatment in patients aged 1–71 years on symptomatic medication prescriptions. Anonymised individual-levelled data was drawn from the Japanese Medical Data Vision (MDV) database to identify patients with AR based on having an ICD-10 code of AR. The SQ HDM SLIT-t group additionally had to have ≥2 prescriptions of 6-SQ HDM SLIT-t in the first follow-up year. Patients initiating other AITs or biologics during the pre-index period were excluded. In a sub-analysis, patients with pre-existing AD were sampled based on having an ICD-10 diagnosis code of AD and/or ≥2 AD Rx in the baseline period. Patients receiving SQ HDM SLIT-t were matched 1:1 to AIT-naïve controls and followed for up to 8 years.

A total of 5,947 matched patients were included in the pre-existing AD sub-cohort. The tendency in AD Rx was decreasing in both the SQ HDM SLIT-t and control group post SQ HDM SLIT-t initiation (Figure 1). Although not statistically significant, the reduction in absolute change from baseline in AD Rx among patients in the SQ HDM SLIT-t group was 11% greater in year 4  (-4.19; 95% CI: –3.85, –4.53) vs. controls (- 3.76; 95% CI: –3.47, –4.06) and 25% in year 5(-5; 95% CI: –4.74, –6.16) vs. controls (-4; 95% CI: –3.39, –4.32). 

This exploratory analysis suggests a consistent, although not statistically significant, reduction in AD Rx among patients treated with SQ HDM SLIT-t compared with controls. The increasing separation between groups after completion of 3 years of treatment is compatible with a sustained immunomodulatory effect. While hypothesis-generating, these findings support further investigation of the long-term impact of SQ HDM SLIT-t on AD outcomes.