ADP101 is an investigational multi-food oral immunotherapy (mOIT) drug product for the simultaneous treatment of food allergies to one or more of the following foods: almond, cashew, hen’s egg, codfish, cow’s milk, hazelnut, peanut, pecan, pistachio, salmon, sesame seed, shrimp, soy, walnut, and wheat. Use of single-allergen oral immunotherapy (OIT) in patients with multiple food allergies is limited by a need for multiple products and time for sequential rounds of therapy. Enhanced treatment options for these patients are needed.

A multi-center, Phase 1/2 randomized, double-blind, placebo-controlled study (Harmony), evaluated the efficacy and safety of ADP101 in 61 participants aged 4-17 years (NCT04856865). Participants with a qualifying food allergy (QFA) on entry double-blind, placebo-controlled food challenge (DBPCFC), defined as dose-limiting symptoms to ≤100 mg of 1-5 foods in ADP101, were randomized 2:2:1:1 to ADP101 (low-dose target [1500 mg/d; n=21]; high-dose target [4500 mg/d; n=20]) or pooled placebo (n=20). After a flexible up-dosing period, maintenance treatment continued through the Week 40 Exit DBPCFCs. The primary endpoint assessed the proportion of participants tolerating ≥600 mg of at least one QFA without dose-limiting symptoms at Exit DBPCFC. Secondary endpoints evaluated the benefit in multi-allergic participants, including tolerance of ≥600 mg and ≥1000 mg for ≥2 QFAs.

At enrollment, 2/3 of participants were multi-allergic with 49% having ≥2 QFAs with dose-limiting symptoms of ≤100 mg. A higher response rate was evident in the high-dose group compared with the pooled placebo group and was consistent across multiple endpoints (Figure). Secondary endpoint measures of desensitization were notable for the multi-allergic participant population comparing high dose vs placebo (Figure) with responses across non-cross-reactive food groups. ADP101 demonstrated a favorable safety and tolerability profile (Table). TEAEs were mostly Grade 1 & 2, with higher rates in active arms during up-dosing and higher rates in the placebo arm during the DBPCFC period. Study discontinuation rates from adverse events were low, with 1 in each treatment arm. Grade 3 anaphylaxis events were infrequent, and none were attributed to ADP101. There were no Grade 4 or 5 adverse events. 

Based on these successful desensitization and safety results, further study of ADP101 in a Phase 3 trial is warranted.