Real-world Assessment of Anaphylaxis and Eosinophilic Esophagitis with 12 SQ House Dust Mite SLIT-tablet Sublingual Immunotherapy

Background Sublingual immunotherapy (SLIT) with 12 SQ House Dust Mile SLIT-tablet (HDM SLIT-tablet) for dust mite-induced perennial allergic rhinitis is reported as effective and safe. Although serious allergic reactions (SAR) and eosinophilic esophagitis (EoE) infrequently occurred under trial conditions, safety of HDM SLIT-tablet under real-world conditions is unknown. Objective To estimate the incidence of SAR and EoE due to HDM SLIT-tablet . Methods Using administrative data from Kaiser Permanente Southern California, this prospective observational study identified patients newly administered HDM SLIT-tablet with follow-up until SLIT discontinuation or end of study. Suspected cases of SAR and EoE were detected using ICD-10 diagnosis and Current Procedural Terminology procedure codes and medication dispense records. A three-member Clinical Review Committee of allergists adjudicated suspected reactions. The incidence rate of confirmed SAR and per 1000 person-years of exposure were determined. Results Five hundred twenty-one patients (93.9% adult and 6.1% pediatric) were exposed to HDM SLIT-tablet from January 2018 through May 2023 for 440.4 person years of exposure. Patients were 39.3±14.1 years of age, 58.7% female, 44.3% non-Hispanic White patients, 40.3% with asthma, and 15.0% with gastroesophageal reflux disease. SAR occurred in 1 adult patient, and during initial HDM SLIT-tablet challenge occurred in 2 pediatric adolescents for an overall incidence of 6.8 (95% CI, 2.2-21.1) SAR per 1000 patient-years. EoE occurred in 1 adult patient (Grade 1 severity) for an overall incidence of 2.3 (95% CI, 0.3-16.1) EoE per 1000 patient-years. Conclusions This real-world study demonstrated that SAR and EoE were infrequent events with HDM SLIT-tablet use supporting its safety and need for physician supervision with initial challenge.