Peanut oral immunotherapy at a single academic medical center using a volume-based approach with store-purchased peanut products.

Background: Incorporation of peanut oral immunotherapy (OIT) into clinical practice is increasing, but the approaches used and reported outcomes vary. Objective: Our aim was to describe a volume-based dosing approach for OIT using store-bought peanut powder in a pediatric population and report initial outcomes. Methods: A standardized, volume-based OIT protocol using non-pharmaceutical-grade peanut powder was developed at a single academic center. Retrospective chart review was completed for patients (aged 8 months-18 years) who underwent single-food peanut OIT using this approach. OIT effectiveness was evaluated by determining the proportion of patients who (1) reached maintenance therapy and (2) tolerated a cumulative desensitization challenge using 6 g of peanut protein after 1 year of high-dose maintenance therapy. Tolerance to alternative peanut products with estimated equivalent peanut protein was also evaluated. Safety was assessed through clinical reporting of adverse reactions, retrospective assessment of severity of reaction symptoms, epinephrine use, and diagnosis of eosinophilic esophagitis. Results: Of the 76 patients, 82% reached maintenance therapy. The 31 patients who achieved a high daily maintenance dose for at least 1 year completed a desensitization challenge; 94% demonstrated clinical tolerance. All patients challenged with equivalent doses of alternative peanut products were tolerant. The most common adverse symptoms were gastrointestinal symptoms (43%); 5 patients (6.6%) received treatment with epinephrine, and 1 patient (1.3%) was diagnosed with eosinophilic esophagitis. Conclusions: A volume-based approach using store-bought peanut powder can be implemented in clinical practice for oral desensitization in pediatric patients with peanut allergy. Although mild adverse symptoms are common, patients can tolerate transitions between peanut products, and some tolerate desensitization challenge, allowing for limited dietary consumption.