Sublingual Immunotherapy for Peanut Allergy: A Randomized, Double-Blind, Placebo-Controlled Multicenter Trial

Conference Paper

2012

AAAAI - American Academy of Allergy, Asthma & Immunology

129(2)

AB66

03/02/2012

RATIONALE: To investigate the safety, efficacy, and immunologic effects of peanut sublingual immunotherapy (SLIT). METHODS: After a baseline oral food challenge (OFC) of up to 2gm (median tolerated dose 46mg), 40 subjects, aged 12-37 (median 15) years, were randomized 1:1 across 5 sites to receive daily peanut (escalating from .00017mcg to 1386mcg) or placebo SLIT. A 5gm OFC was performed after 44 weeks. Placebo subjects then crossed-over to peanut SLIT to a maximum of 3696mcg, followed by a week-44 5gmOFC.Week-44OFCwas compared to baseline OFC; subjects successfully consuming 5gm or at least 10-fold more peanut than baseline OFC threshold were considered ‘‘responders.’’ RESULTS: 14/20 (70%) subjects receiving peanut SLIT were responders compared to 3/20 (15%) receiving placebo (p50.001). In peanut-SLIT responders, median successfully consumed dose increased from 3.5mg to 496mg; none tolerated the entire 5gm OFC. Of 10,701 peanut doses through week-44 OFCs, 61.6% were symptom-free; excluding oral/pharyngeal symptoms, 95.2% were symptom-free. Basophil activation did not decline significantly from baseline to 44 weeks; median peanut-IgE levels significantly declined from weeks 29 to 44 in the peanut group compared to placebo (p50.01). 6/15 crossover subjects with week-44 OFC assessment to date were responders; median successfully consumed dose increased from 11mg to 496mg. Three subjects (2 peanut,1 placebo) withdrew during the blinded phase prior to week-44OFCs; 9 subsequently withdrew(3 peanut,6 original placebo). CONCLUSIONS: Initial results demonstrate that peanut SLIT can safely induce significant, low-level desensitization in a majority of subjects. Maintenance dosing is ongoing for 3 years to determine further efficacy.