Oral Immunotherapy in Peanut-Allergic Adults Using Real-World Materials

Peanut oral immunotherapy (OIT) has shown effectiveness in achieving desensitization of children; however, evidence in adults is lacking.

This phase II trial evaluated peanut OIT in peanut-allergic adults using real-world peanut products. A Simon's minimax two-stage design, incorporating a stop:go for futility, was employed. A separate untreated control group was also recruited for comparison of mechanistic parameters. Participants underwent baseline double-blind placebo-control food challenges (DBPCFC) with peanut protein doses of 0.3 to 300 mg. Reacting participants were initiated on daily OIT with 2-weekly updosing until reaching a maintenance dose of 1000 mg (four large peanuts). The primary outcome was the proportion of OIT participants who tolerated a cumulative dose of 1.4 g peanut protein during exit DBPCFC (doses provided 0.3-3000 mg).

Twenty-one adults (8 female; mean age 24.2 years [SD 4.9]) were enrolled in the OIT group, with 67% achieving the daily maintenance dose and meeting the primary endpoint. Three withdrew due to adverse reactions, and a further three did not complete the trial for reasons unrelated to OIT. The median tolerated dose increased from 30 mg (equivalent to approximately 1/8th of a peanut) to 3000 mg (12 peanuts) at the exit challenge, representing a 100-fold increase (p < 0.0001). OIT was associated with an improvement in QoL measures. Suppression of peanut skin prick test sizes and induction of peanut-specific IgG were observed in OIT but not in control participants.

Peanut OIT appears to be an efficacious treatment for adults with peanut allergy. Further studies are needed for confirmation and to characterize safety profiles in different adult subgroups.

Grown Up Peanut Immunotherapy (GUPI) study; ClinicalTrials.gov identifier: NCT03648320.