The following is a summary of “Real-world, long-term effectiveness of allergy immunotherapy in allergic rhinitis: Subgroup analyses of the REACT study,” published in the AUGUST 2023 issue of Allergy & Immunology by Contoli, et al.
Previous randomized controlled trials have established the effectiveness of allergy immunotherapy (AIT) in treating allergic rhinitis (AR) and the disease-modifying benefits of the SQ grass sublingual immunotherapy (SLIT) tablet. For a study, researchers sought to evaluate the real-world, long-term effectiveness and safety of various AIT subgroups, including different routes of administration, therapeutic allergens, persistence to AIT, and the SQ grass SLIT tablet.
The primary outcome of the retrospective cohort study (REAl-world effeCtiveness in allergy immunoTherapy; conducted from 2007 to 2017) focused on assessing AR prescriptions within specified AIT subgroups among subjects with AR, comparing those with and without AIT prescriptions (controls). The safety analysis included monitoring anaphylaxis occurrences for up to two days after the first AIT prescription. Subgroup follow-up continued until the sample size dropped to fewer than 200 subjects.
Both subcutaneous immunotherapy (SCIT) and SLIT tablets demonstrated greater reductions in AR prescriptions compared to controls (SCIT vs. SLIT tablets: year 3, P = .15; year 5, P = .43). Grass- and house dust mite–specific AIT showed comparable reductions in AR prescriptions exceeding those of controls, whereas tree-specific AIT exhibited significantly smaller reductions (tree vs. house dust mite, and vs grass: years 3 and 5, P < .0001). Greater persistence to AIT was associated with more substantial reductions in AR prescriptions than non-persistence (persistence vs. non-persistence: year 3, P = .09; year 5, P = .006). The SQ grass SLIT tablet maintained sustained reductions in AR prescriptions versus controls for up to 7 years (year 3, P = .002; year 5, P = .03). Anaphylactic shock rates were low (ranging from 0.000% – 0.092%), with no incidents reported for SQ SLIT tablets.
The study underscored AIT’s real-world, long-term effectiveness, corroborating the disease-modifying effects observed in randomized controlled trials of the SQ grass SLIT tablet. It also emphasized the importance of utilizing evidence-based AIT products for tree pollen-related AR.