Personalizing Peanut Oral Immunotherapy by Baseline Reactivity

Announcer:
You’re listening to Clinician’s Roundtable on ReachMD. On this episode, we’ll hear from Dr. Scott H. Sicherer, who’s a Professor of Pediatrics and the Director of the Jaffe Food Allergy Institute at the Icahn School of Medicine at Mount Sinai in New York. He’ll be discussing his presentation at the 2026 American Academy of Allergy, Asthma, and Immunology Annual Meeting, which focused on how factors such as baseline threshold of allergic reactivity may influence sustained unresponsiveness after oral immunotherapy. Here’s Dr. Sicherer now.   

Dr. Sicherer:
So it's interesting that most of the studies on peanut allergy, for example, were looking at people who reacted to 143 milligrams of peanut or less, and that amounts to about half of a large peanut. And that makes total sense that that's what the studies were focusing on because if you're so sensitive that a tiny amount's gonna be a problem, you are not safe from a small accidental exposure. And if you can get a person like that to tolerate a couple of peanuts, you've already made a huge improvement in their threshold and you've improved their safety a lot. But maybe something was being missed by focusing on these people who are super sensitive, and there were already studies out there that were hinting that maybe people who were less sensitive who may be tolerated a little bit more than that tiny amount of peanut would be easier to treat, would maybe be able to get onto larger amounts of peanut, or maybe would even achieve that sustained unresponsiveness that's been pretty elusive for people who are super sensitive to small amounts.  

So we designed this study looking at children who were 4 to 14 years of age who reacted to one and a half large peanuts but were able to tolerate that half of a peanut amount that I mentioned earlier, and we also included people that still were reacting up to about 17 peanuts. So basically, they had a higher threshold of reactivity than most of the people that had been studied before. And we treated them with oral immunotherapy and we had—it was a randomized study—essentially half of them continue avoidance. Because they were not super sensitive, we were able to use off-the-shelf supermarket products, like peanut butter, and we could give them measurable amounts—so amounts that they could measure at home, like an eighth of a teaspoon or a quarter of a teaspoon. And we actually got them gradually up to about a tablespoon of peanut. And then after they were on that amount, we left them on that amount for a period of time that we call a maintenance period of treatment. And then we tested them with a feeding test to see if they were desensitized. But in this study, we actually went up to an amount that was 9 grams, which is like 30 large peanuts. It's more than a typical serving of peanut butter. And in this study, according to our analysis and the way that we designed it, we found that all of the treated children were able to tolerate that full serving of peanut after they received this therapy.  

Now the next question is about that sustained unresponsiveness. So what happens when we take them off therapy? Well, we made a decision in this study that we're gonna try to make this a lot like real life. And so what would happen in real life? You found out that you could eat peanut butter, but you had an allergy. We know that you're probably going to eat it at least sometimes, but we wanted to see, are you gonna be safe if you acted natural? So what does that mean? We had them eat peanut ad-lib for 16 weeks, and then we had them stop entirely like, ‘you're not allowed to eat any peanut for eight more weeks.’ So that is something that we made up to match what maybe someone in real life would do. They would eat it here and there. We wanted them to eat about a tablespoon a week if they could. But then we made them stop eating it. And that might happen if someone is just like, ‘ah, yeah, I forgot to eat peanut for a while.’  

And our result for doing another feeding test was that according to what we call an intention to treat analysis—in other words, including everyone who started the study—68 percent were still able to tolerate all 9 grams of peanut, and that compares to less than 9 percent of those who were not treated. Now, per protocol analysis means that we're including people who basically followed the rules and stayed in the study and got all of their evaluations done, and there we saw 87 percent were able to still ingest a full serving of peanut, which is way higher than the studies had shown previously where it was more like about a third of the people tolerated it after they had stopped eating it. 

So we were very happy with those findings, and although it's not a cure, it was an example of the difference in threshold of that starting group being able to attain high rates in sustained responsiveness. All of that together really makes you say that there really should be a personalized approach to the oral immunotherapy. It may be possible to identify through a feeding test who has this higher threshold and maybe they could progress through treatment faster, expect less problems, and then have a more enduring response. 

Announcer:
That was Dr. Scott H. Sicherer sharing highlights from his presentation at the 2026 American Academy of Allergy, Asthma, and Immunology Annual Meeting. To access this and other episodes in our series, visit Clinician’s Roundtable on ReachMD.com, where you can Be Part of the Knowledge. Thanks for listening!