Sustained Unresponsiveness after Sublingual Immunotherapy for Peanut-Allergic Children

Peanut oral immunotherapy (OIT) has been shown to induce sustained unresponsiveness (SU) in up to 50% of subjects. Although desensitization has been demonstrated with peanut sublingual immunotherapy (SLIT), its ability to induce SU has not been well described. Children ages 1-11 years with peanut allergy were treated with 2 mg of peanut SLIT. A previously reported interim analysis demonstrated successful desensitization after 12 months of treatment. This cohort continued treatment for a total of 36-60 months and then underwent a 5000 mg peanut oral food challenge (OFC) to further assess desensitization. Subjects passing the challenge discontinued SLIT dosing for 2-4 weeks and were then re-challenged with 5000 mg of peanut protein to assess for SU. Out of 37 subjects completing the study, 32 (86%) safely ingested >300 mg of peanut and 12 (32%) passed the 5000 mg OFC at the end of SLIT therapy. The median successfully consumed dose (SCD) of peanut for the cohort was 1750 mg and the mean was 2561 mg (range 0-5000 mg). The 12 subjects who passed the OFC were re-challenged with 5000 mg of peanut 2-4 weeks after discontinuing SLIT, of which 10 subjects (27%) passed demonstrating SU. The remaining 2 subjects had SCDs of 3750 mg during the SU challenge. These results demonstrate that peanut SLIT induces clinically significant desensitization in the majority of subjects and can induce SU in a subset of children treated for at least 36-60 months.