PURPOSE OF THE STUDY.
To indirectly compare the effect of sublingual immunotherapy tablets (SLIT) with selected pharmacotherapies versus placebo on nasal symptom scores in perennial (PAR) and seasonal allergic rhinitis (SAR).
Twenty-three SAR trials and 11 PAR trials with 18 914 patients were included in the analysis. Subjects enrolled in the trials ranged from 5 to 85 years of age.
The authors pooled analyses from randomized, double-blind, placebo-controlled trials of SLIT to timothy grass, short ragweed, and house dust mite (HDM) and pharmacologic treatments with montelukast, desloratadine, and mometasone furoate nasal spray (MFNS). Unpublished ad hoc data on file with the manufacturers were also used. Total nasal symptoms scores (TNSS) with treatment were compared with placebo.
Relative to placebo, TNSS improvements in the grass SAR trials ranged from 4.0% to 27.2% (overall 16.3% improvement as compared with placebo). In the 2 ragweed SLIT studies, overall improvement relative to placebo was 17.1%. These treatment effects were numerically greater than those for montelukast (0.65% to 10.3%, overall 5.4% improvement compared with placebo) and desloratadine (1.7% to 12.5%, overall 8.5% improvement compared with placebo). In contrast, MFNS had a numerically greater effect than did SLIT (13.1% to 28.1%, overall 22.2% improvement compared with placebo). In 2 studies of HDM SLIT for PAR, overall TNSS improvement was 16.1% higher than with placebo. This effect was greater than that seen for montelukast, desloratadine, and MFNS (3.7%, 4.8%, and 11.2% improvement compared with placebo, respectively).
As compared with placebo, grass and ragweed SLIT are more effective at lowering TNSS than montelukast and desloratadine but somewhat less effective than MFNS. HDM SLIT had a greater effect on TNSS than the pharmacologic treatments.
Currently, the FDA has approved SLIT tablets for grass and house dust mite allergies. The currently available preparations are very expensive and often not covered by insurance. A great weakness in the study and marketing of new products is that they are usually not compared with existing products in head-to-head studies. Subcutaneous allergen immunotherapy (SCIT) has been proven effective (and more effective than pharmacotherapy) for numerous (but not all) aeroallergens. SLIT tablet doses are not easily compared with SCIT doses, but data indicate that significantly higher monthly doses of SLIT than SCIT are necessary for efficacy. At this point, if a patient has isolated allergies to grass, ragweed, or dust mites, SLIT tablets are an option, but cost and other factors (such as the potential for long-lasting therapeutic benefit with SLIT) must be considered in the discussion between patients and their allergists.
- Copyright © 2017 by the American Academy of Pediatrics