DocTalk Podcast: Treating Food Allergies with Whitney Morgan Block

The toolbox for food allergy care is beginning to fill up.

Though there are currently no drugs approved for marketing by the US Food and Drug Administration (FDA) for the treatment of food allergy, a series of immunotherapy and biologic options have neared closer to indication. How they will each come to benefit the field of patients—particularly, pediatric patients—is still being assessed in clinical trials.

In the final segment of a three-part DocTalk chat on food allergy, Whitney Morgan Block, MSN, CPNP, FNP-BC, president, chief executive officer and founder of the National Allergy Center, shared her perspective on what’s to come in food allergy treatment.

Here is part 1 of the chat, on cause and prevention.

Here is part 2 of the chat, on diagnosis.

For more of the DocTalk Podcast, be sure to subscribe on iTunes.

MD Mag: Hello everybody, and welcome to the DocTalk podcast. I'm Kevin Kunzmann, managing editor of MD Magazine®, and I'll be your host for this edition of DocTalk. Today, we are joined by nurse practitioner Whitney Morgan Block, CEO, president, and founder of the National Allergy Center, as we discuss the final portion of our three-part chat on food allergy care.

Whitney, we've already hit on some topics on food allergy prevention and diagnosis. And now we're looking to tie this whole thing up with a bigger talk on treating food allergies. So if you wanted to start off with anything before we got going, go ahead.

Block: No, I think that this is really an exciting time in the world of food allergies. And for such a long time, the standard of care in food allergies for patient was avoid the foods that you're allergic to. And that's changing, now that there are new therapies available, giving patients options.

MD Mag: Yeah, absolutely. I think it's a very optimistic conversation we're about to have. So let's dive into it a little bit with our first question—and that's really to expand a bit more on your thoughts on this growing pipeline of food immunotherapy options that we're seeing today.

Block: Yeah, so I think it's really exciting that we have options now, versus what we didn't have before. So, one new therapy is called oral immunotherapy sometimes called shortened to OIT for short. During it, you start eating a very low dose of the food you're allergic to, and gradually build up over time, to train your body to tolerate the food without having an allergic reaction. Another type of therapy is called sublingual immunotherapy, also known as SLIT, where you put drops of the food that you're allergic to in liquid form, under your tongue to train your body, in the same kind of way gradually building up. And another way is called the epicutaneous immunotherapy, which is also known as patch therapy, where you wear a patch with some of the allergen on your skin to get to a state of desensitization.

As with all therapies, all of them have advantages and disadvantages that have to be weighed for the individual patient. Since I worked at Stanford University for about 6 years and worked on research studies involving all 3 of these types of therapy, I know quite a lot about them and about their side effects and everything. When I opened the national allergy center in 2017, we started offering outside of research trials, oral immunotherapy with or without a medication called Xolair, which we can get into in a little bit.

MD Mag: Great, yeah, I'm looking forward to discussing that a bit more. It's come up certainly a lot in some previous reporting that we've done here at MD Mag. But, touching strictly on these food immunotherapies—obviously, with all the new data, all the promising data that's been coming out, there's also some additional necessary conversations that need to happen about side effects.

So could you expand a bit more and exactly what these side effects are that we're seeing—any adverse events, and any causes for concern for treating physicians?

Block: Yeah, let's talk about that. So the most common side effects for all 3 therapies are pretty similar. The biggest side effect of SLIT is itchiness, in the mouth and the throat. The biggest side effect of patch therapy is itchiness at the site as a patch where it's applied. And the biggest side effect of OIT is itchiness at the mouth and in the throat, and as well as abdominal pain.

With OIT in particular, those symptoms are very common, with about 80% to 85% of people getting them at some point during their therapy. And although uncomfortable, those symptoms typically are very dangerous. In many research studies, OIT is found to have more side effects compared to SLIT and patch therapy, but it's also found to be quite a bit more effective. The majority of reactions seen in OIT are mild, and many don't even require treatment. One of the most common questions I get from parents is 'Is my kid getting epi during OIT?'

And we did a research study over at Stanford, and analyzed about 42,000 OIT doses and found the rate of epinephrine use ranged throughout the year from 0.5-2.0 administrations in every 1000 doses taken. So you can tell, the rate of epinephrine administration is pretty darn low.

Another side effect that's worth mentioning is a disorder called eosinophilic esophagitis, or EoE for short. It's a really rare disorder, where use eosinophils start accumulating in the esophagus, where they're not supposed to be. Over time, you might start feeling symptoms, like trouble swallowing, a sticky pancake feeling in the back of the throat, nausea, or vomiting. It can easily be overlooked if you don't know what you're looking for, since it's not IgE-mediated. We talked before about what IgE-mediated means, and how those reactions typically occur quite quickly, within a few minutes to two hours after you eat the food. With EoE it takes time for the eosinophils to migrate to the esophagus. So EoE symptoms, you typically won't see immediately after eating an allergen. You might see them hours or even days later.

MD Mag: That's great to know. Thank you for that. And this is a question that's certainly going to come up as we get to a place where these therapies are on the market, more readily available for patients, and being compared more aggressively with one another. But if maybe we can try to answer it now: is there one therapy that works best for patients, or at least better than the others we have?

Block: Different therapies may work best for different people, depending on personal goals and individual circumstances. From an advocacy standpoint, though, it seems that OIT might be the most effective of the 3. If we just talk about peanut as an example, you should understand that there's about 240 milligrams to 300 milligrams of protein in 1 peanut, and we talked about how you're allergic to the protein of part of the peanut.

So in one patch study, after a year of wearing an active patch, about 53% of kids aged 4-11, could eat at least 300 milligrams of protein, or about 1 big peanut. We think that the patch might be more effective in younger kids, and that's why they're currently doing the trial with the patch and kids 1-3 years old. So we don't have that data out yet, but that's really promising, that number might be a little bit better. And it might be more efficacious in the younger kids.

Regarding SLIT, in one study done with kids aged 7-13 years old who did therapy for about a year, 90% of them passed a challenge to a little over 496 milligrams of protein, which is about 2 peanuts.

Compare that to an OIT study, where the same aged kids did therapy for about a year. About 64% of them were able to tolerate 7246 milligrams of protein, which is about 30 peanuts. So it seems from that data, you can tell that OIT can give you protection to a higher amount of peanut, quicker than SLIT or patch therapy. The other thing to consider is that about 40% of kids are allergic to more than one food. There have been multiple allergen OIT studies, but I've never actually seen a multi-allergen SLIT study. And the company who makes the patch hasn't studied anything except a peanut patch and a milk batch. So I think for those 40%, it seems like oh, it might be the best option at this point.

MD Mag: Well, that's great to know. And I'm interested to see how it shakes out as the field continues to advance and we have more considerations to make in terms of therapy options. And speaking of one therapy class that has been really making headlines, especially in inflammation care and type 2 inflammation and other related fields—biologics. How do we see them figuring into allergy treatment now?

Block: Biologics seem to be a useful tool in food allergy treatment. There's a medication called Xolair, which is FDA-approved for severe asthma and idiopathic urticaria, which is a fancy way of saying people that randomly break out in hives. We've been using it in food allergy treatment for over 7 years to accelerate the desensitization process. The way it works is that it blocks IgE receptors, allowing the food to be introduced quicker than if those receptors weren't blocked.

This can greatly reduce the amount of time it takes to reach a maintenance dose. For example, for peanut without Xolair, it might take 6-8 months to build up to 2 peanuts. Well with Xolair, it may take a day to 2 weeks to get up to those same 2 peanuts. It's exciting—back in 2018, just last year, the FDA granted breakthrough designation therapy status to Xolair for the prevention of severe allergic reactions. And this is therapy we're currently offering, this combination therapy of OIT plus Xolair as an option for patients at the National Allergy Center. And we use Xolair in kids and eligible kids over the age of 4 years old.

Another biologic that we're looking at in research studies is a medication called Dupixent, or dupilumab. It's FDA-approved for asthma and eczema. And it doesn't block IgE receptors, but instead blocks another inflammatory pathway that we think may prevent allergic reactions from occurring.

So it'll be interesting to see how that pans out, to see if one works better than the other, if Xolair's better than dupilumab, or if vice versa, or maybe there's some combination of the 2 to make it work even better. It's still kind of unknown.

MD Mag: Yeah, it's just fascinating to think that, at this date and time in 2019, we have no approved, marketed therapy for food allergy. And in just a few years, we may be looking at a loaded, competitive market filled with a biologic options, direct options, all these capabilities. It's going to be really fascinating. But that's even in just a year or 2 from now. What do you see in the next 5 years, that the field of new allergy therapy looks like for us?

Block: In the next 5 years, I think the food allergy field will most certainly keep growing and gaining a ton of knowledge. We still have a lot of questions out there about what therapy is best for which people, what the best maintenance doses are, how long you need to be on that maintenance dose, which biologic should be used, or maybe a combination of biologics.

There's also an interesting study that's currently being conducted on a DNA vaccine. The way that works is that the vaccine kind of contains the blueprint for how to make a peanut and once it's in your body, your body uses that blueprint to create its own peanut protein. And the thought is that if your body is making its own peanut protein, then it knows what it looks like. And then when you eat a peanut, your body wouldn't think it's a danger and won't react. This technology's been shown to be effective in people with Japanese cedar tree allergy, but that's a little different, since you don't really eat Japanese cedar trees.

MD Mag: Certainly excited to see what more will come from it. So, is there anything else you'd want to add, relative to this therapy talk? Any other looking forward statements you have?

Block: I think the biggest takeaway message from all of this is that avoidance isn't the only option anymore. There are therapies available now, and there's more on the horizon. So I would encourage everybody to do their research and seek out experienced clinicians that can offer explanation and guidance on what's best for the individual patient.

MD Mag: Yeah, it just seems that, just like any other field in medicine, the best hope you have is to eventually have individualized therapy, personalized care options. But a big portion of that is the requirement of education, both physician and patients themselves. So it's going to be interesting to see how that all shakes out. But I definitely have to echo that—do your homework, communicate, figure out what's going to work best for you.

Thank you so much, Whitney. Again, this was our final talk of this three-part series on food allergy care. And if you have any closing thoughts you would have for the audience, please go ahead.

Block: Thank you for letting me come on and speak. And if anybody has any questions, feel free to reach out to me. My email address is Whitney@NationalAllergyCenter.com. Feel free, regardless of whether you're a patient or whether you're a doctor, if you have any questions about oral immunotherapy or food allergy treatment or diagnosis or prevention—any of that, I'm free to answer any questions.

MD Mag: Thank you so much again, Whitney, and thank you to all of our listeners. We'll be back with a new episode next week. But for now, be sure to check out parts 1 and 2 of our food allergy chat with Whitney, on cause and prevention, and diagnosis. And for the latest on all food allergy news, be sure to visit MDMagazine.com. I'm Kevin Kunzmann, and thank you for listening to DocTalk.