Developing a Standardised National Model of Care for Treatment of Peanut Allergy in Infants: The <scp>ADAPT</scp> Peanut Oral Immunotherapy Program

INTRODUCTION: Peanut allergy is the most common food allergy in Australian school-aged children and is rarely outgrown. Access to oral immunotherapy (OIT), a disease-modifying treatment for food allergy, is limited in many regions of the world, including Australia. Clinical trials show high rates of allergic desensitisation and remission are being achieved, particularly in young children, but significant variability in protocols and implementation prevents large-scale evaluation of clinical and patient-reported safety, effectiveness and long-term outcomes. A standardised national model of care OIT program has not been previously attempted. In Australia, the National Allergy Centre of Excellence partnered with 10 paediatric hospitals to develop and implement the ADAPT OIT Program, which aims to change the trajectory from 'Allergy Development to an Accelerated Pathway to Tolerance'. The Program was designed after extensive international expert and consumer consultation, and attempts to be pragmatic, feasible by using existing resources, and equitable, with out-of-pocket costs to families limited to the purchase of the OIT product, store-bought peanut flour. METHODS: In July 2024, the ADAPT OIT Program was launched. Infants were considered if they had a history consistent with an IgE-mediated allergic reaction to peanut < 12 months of age and evidence of sensitisation (peanut SPT ≥ 3 mm; peanut sIgE or ara h 2 sIgE ≥ 0.35kUA/L). A threshold oral food challenge (OFC) was done to confirm a diagnosis of peanut allergy using teaspoon measures (1/64th, 1/32nd, 1/16th, 1/8th, ¼, ½, 1 tsp. peanut flour, cumulative dose of 2435 mg peanut protein), and to determine the OIT starting dose unless the index reaction was a CoFAR Grade 3+. In this case, infants started OIT with a microdose escalation commencing with a red microspoon of peanut flour (3 mg peanut protein) up to a maximum of 1/64th tsp. (15 mg). Up-dose stage visits were conducted every 4 weeks until the maintenance stage was achieved (1/2 tsp. of peanut flour: 650 mg peanut protein). After 2 years of OIT, infants had an 8-week period of strict peanut avoidance followed by an OFC to assess for sustained unresponsiveness (SU). Infants were followed up for a minimum of 12 months post SU OFC. CONCLUSION: The ADAPT OIT Program aims to make best-practice peanut OIT accessible to a significant proportion of infants with peanut allergy in Australia. Under a national standardised model, with rigorous and timely evaluation, the Program design enables optimisation over time for maximal impact.