A Randomized, Double-Blind, Placebo-Controlled Pilot Study of Sublingual versus Oral Immunotherapy for the Treatment of Peanut Allergy

Abstract

To compare safety and efficacy of oral versus sublingual immunotherapy (OIT and SLIT) for the treatment of peanut allergy. After a baseline double-blind placebo-controlled food challenge (DBPCFC, maximum 1gm peanut protein), subjects were randomized to active SLIT/placebo OIT or active OIT/placebo SLIT. After initial escalation, SLIT/OIT doses were increased biweekly/weekly to 3696μg/day SLIT and 2000mg/day OIT. A 10gm DBPCFC was completed after 6 months of maintenance. 21 subjects, 7-13yrs (median 11.1; male 52%) were enrolled. Baseline characteristics included median total IgE 667kUa/L (range 170-1557), peanut IgE 169kUa/L (35.1-814), peanut IgG4 1.12mgA/L (0.19-5.89), 5-log peanut endpoint skin titration (PEST) mean wheal 5.5mm (1.3-8.9), and DBPCFC threshold 21mg (1-146). Three subjects withdrew (1 systemic reaction, 1 GI symptoms, 1 unrelated to study). There were significant increases at maintenance in total IgE (median 844, range 201-3938; p<0.001), peanut IgE (344, 47.4-1960; p<0.001), and peanut IgG4 (5.79, 0.47-47.2; p<0.001). Of the 9 subjects completing the 6 month DBPCFC, median challenge threshold increased to 246mg (21-4996; p<0.05) and PEST mean wheal decreased to 1.8mm (range 0.7-7.2; p<0.05). Significant increases in total and peanut IgE remained (p<0.05). Symptoms elicited by the 4772 home doses included: 15.4% oropharyngeal, 10.2% GI, 3.8% lower respiratory, 2.4% skin, and 0.9% upper respiratory. Treatment included antihistamines (43.2% of doses), beta2-agonists (1.3%), and epinephrine (1 dose). Preliminary results demonstrate peanut SLIT and OIT are effective in changing challenge threshold, serologic markers, and skin reactivity with infrequent systemic symptoms. SLIT versus OIT will further be compared after unblinding following the 12 month DBPCFC.