ADP101 multifood oral immunotherapy for food-allergic patients: Harmony phase 1/2 randomized clinical trial

Background

Oral immunotherapy is an established approach to desensitize the immune system in the context of allergic disease; however, the only currently approved product is for peanut allergy. ADP101 is a novel, pharmaceutical-grade, multifood oral immunotherapy in development to simultaneously treat single or multiple food allergies, containing allergenic proteins from 15 foods in equal parts by protein weight.

Objective

The phase 1/2 Harmony trial (NCT04856865) evaluated efficacy and safety of ADP101 in participants with qualifying allergy to 1 to 5 foods in ADP101, defined as dose-limiting symptoms with a ≤100 mg challenge dose during double-blind, placebo-controlled food challenge (DBPCFC).

Methods

Participants were randomized to low-dose (1500 mg/d; 100 mg protein per food) or high-dose (4500 mg/d; 300 mg protein per food) ADP101, or matched placebo, with dose escalation followed by daily maintenance dosing over 40 weeks. The primary endpoint was the proportion of participants tolerating a ≥600 mg challenge dose of a single qualifying food without dose-limiting symptoms at the Week 40 Exit DBPCFC (ie, responders).

Results

In the primary analysis population (61 pediatric participants aged 4-17 years), a greater response rate was observed in both the high-dose ADP101 (55.0%) and low-dose ADP101 (38.1%) groups compared with pooled placebo (20.0%) (nominal P = .048, P = .306, respectively; adjusted for multiple comparisons, P = .097, P = .306, respectively). Desensitization to ≥2 foods was observed in individuals with multiple food allergies, as was desensitization at levels over 600 mg. ADP101-treated participants showed an overall reduction in skin-prick test reactivity, with an increase in maximum tolerated dose across the majority of foods tested. Adverse events were mostly mild or moderate, with no life-threatening events or deaths.

Conclusions

The study did not meet its primary endpoint, but ADP101 demonstrated a favorable safety profile and increased the reactive threshold in DBPCFC in pediatric participants with single or multiple food allergies across multiple endpoints, warranting further clinical investigation.