Peanut Oral Immunotherapy Using 30 and 300 mg Maintenance Doses

Abstract

Background: The lowest dose of peanut oral immunotherapy (P-OIT) has not been determined.

Objective: To evaluate whether very low-dose oral immunotherapy (30 mg) may safely and effectively increase tolerated doses and induce immunologic changes.

Methods: We prospectively enrolled peanut-allergic children reactive to 444 mg peanut protein (PP) or less in double-blind placebo-controlled food challenges (DBPCFC) and randomly assigned them to three groups. Two were double-blinded P-OIT groups escalating to 30 mg (Group 30 mg) or 300 mg (Group 300 mg) PP maintenance doses. A third group followed open-label avoidance (Group Avoid). Cumulative tolerated doses of 443 mg or greater and 1,043 mg or greater PP were compared with Group Avoid by DBPCFC planned at 1 year. Safety and laboratory parameters (specific IgE and specific IgG₄) were assessed.

Results: We enrolled 51 children (26 male [51%], median age 10 years; interquartile range, 7-13 years) with initial cumulative-tolerated dose of 44 mg (interquartile range, 14-144 mg). In Group 30 mg, 15 of 17 patients completed DBPCFC (two of 17 withdrew). In Group 300 mg, 12 of 17 patients completed DBPCFC (five of 17 withdrew). In Group Avoid, 12 of 17 completed DBPCFC (five of 17 were lost to follow-up). By intention to treat, in Group 30 mg, 13 of 17 patients (P < .001 vs Group Avoid) tolerated 443 mg or greater PP, and seven of 17 (P = .007 vs Group Avoid) tolerated 1,043 or greater mg PP. In Group 300 mg, 10 of 17 patients (P ≤ .001 vs Group Avoid) tolerated 443 or greater mg PP, and eight of 17 (P = .003 vs Group Avoid) tolerated 1,043 mg PP. No patients in Group Avoid (0 of 17) tolerated 443 or greater mg PP or 1,043 or greater mg PP. Laboratory parameters (specific IgE and specific IgG₄) were similar between Group 30 mg and Group 300 mg and significantly improved from Group Avoid. Systemic adverse events were fewer in Group 30 mg compared with Group 300 mg.

Conclusions: A 30 mg maintenance dose for P-OIT significantly increases the threshold over strict avoidance, clinically similarly to 300 mg, and may allow for a simplified and safer immunotherapy regimen and fewer treatment dropouts.

Keywords: Low dose; Peanut allergy; Peanut oral immunotherapy.