Single oral immunotherapy desensitizes patients to multiple foods
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- ADP101 includes 15 substances from the nine most common allergens.
- 56% of participants with multiple allergies on the high dose of ADP101 achieved desensitization to two or more foods.
ANAHEIM, Calif. — A multi-food oral immunotherapy achieved desensitization in children with allergies to two or more foods, according to a poster presented at the American College of Allergy, Asthma & Immunology Annual Scientific Meeting.
Developed by Alladapt Immunotherapeutics, ADP101 is designed to simultaneously treat allergy to one or more foods, Warner W. Carr, MD, FACP, FACAAI, FAAAAI, medical director of Southern California Research at Allergy & Asthma Associates of Southern California, said during the presentation.
“Harmony is a phase 1/2 study of the efficacy and safety of ADP101 for oral immunotherapy in food-allergic children and adults,” Carr said during his presentation. “No multi-food oral immunotherapy treatments are approved in the United States.”
ADP101 is a dry powder mixture that includes 15 drug substances representing the nine most common allergens, including milk, egg, wheat, sesame, tree nuts, soy, fish, shellfish and peanuts, accounting for 90% of severe food reactions in patients with food allergy.
Carr and colleagues assessed ADP101’s use in 61 children (67% male; 67% white) aged 4 to 17 years who were allergic to up to five foods included in ADP101 based on dose-limiting symptoms after doses of 100 mg or less during double-blind, placebo-controlled food challenges (DBPCFCs) at screening.
Collectively, the cohort had 123 qualifying food allergies, with 51% having one qualifying food allergy, 20% with two, 15% with three, 7% with four and 8% with five. Also, 28 patients had non-qualifying food allergies defined as dose-limiting symptoms with more than 100 mg but 1,000 mg or less of food protein in the DBPCFC.
The up-dosing phase escalated doses every 2 weeks, beginning with 5 mg a day and proceeding to the target dose or the highest tolerated dose of 50 mg or more a day.
During the maintenance phase, participants received low doses of ADP101, defined as 100 mg of protein/food/day (1,500 mg total/day; n = 21); high doses of ADP101, defined as 300 mg of protein/food/day (4,500 mg total/day; n = 20); or placebo (n = 20).
Combined, the up-dosing and maintenance dosing phases totaled 40 weeks.
The researchers defined responses as desensitization to a single dose of 600 mg (1,044 mg cumulative) or more of protein from one or more multiple qualifying allergens at 40 weeks.
Response rates in the intent-to-treat analysis included 55% for the high-dose group and 20% for the placebo group (P = .048), in addition to 38.1% for the low-dose group.
“ADP101 demonstrated dose-dependent efficacy with a greater response rate with high-dose ADP101 than placebo,” Carr said.
Participants who achieved tolerance to at least 1,000 mg of one or more qualifying foods included 50% of the high-dose group and 15% of the placebo group (P = .041), as well as 23.8% of the low-dose group.
Also, the multi-allergenic patients in the high-dose group included 55.6% who tolerated at least 600 mg and 44.4% who tolerated at least 1,000 mg of two or more of the qualifying foods, compared with 0% in the placebo group (P = .006 and P = .021, respectively).
“Safety was assessed on day 1 and throughout the study,” Carr continued, noting that Harmony began with a single, 5 mg dose unlike other oral immunotherapies that begin with lengthy initial dose escalation days.
“Treatment-emergent adverse events on day 1 were mild or moderate, infrequent and occurred at a rate similar to placebo, consistent with the low and slow approach to up-dosing in Harmony,” Carr said.
Adverse events were mostly mild or moderate overall as well, the researchers said, with no life-threatening events or deaths. Severe anaphylaxis was infrequent, and the researchers said none of its cases were due to ADP101.
Also, adverse events were more frequent during up-dosing, including adverse events related to treatment. During dose maintenance, no adverse event was reported in more than 50% of participants in any group, and no treatment-related adverse events occurred in more than 10% of any participants.
“Per protocol, epinephrine was encouraged early during allergic reactions,” Carr said.
Primarily, epinephrine was used during up-dosing and for mild or moderate events due to accidental allergen exposure. None of the patients who received ADP101 left the study due to anaphylaxis.
“Importantly, there were no grade 3 anaphylaxis events attributed to ADP101, and no grade 4/grade 5 events,” Carr said.
Alladapt Immunotherapeutics is now preparing for a phase 3 study in 2024.