Doctor weighs risks and benefits of 1st peanut allergy treatment approved in U.S.
Pediatric allergist Marcus Shaker says the treatment 'may cause significant side effects for many patients'
If you have a child with a life-threatening peanut allergy, avoiding foods with that ingredient can be a daily stressor. But a pharmaceutical company in the U.S. thinks it may be able to reduce some of that stress for certain patients.
Aimmune Therapeutics have developed a treatment called Palforzia that they say trains the body to better tolerate peanut through daily doses of a prepared peanut powder.
The treatment has now been approved by the U.S. Food and Drug Administration.
Marcus Shaker is a pediatric allergist at Children's Hospital at Dartmouth in New Hampshire. As It Happens host Carol Off spoke to Shaker about Palforzia and why he thinks the treatment could benefit some patients, but still present significant risks to others.
Here is part of their conversation.
What difference do you think this drug could make for people?
That's the question everybody's asking and it's a difficult question to answer.
The challenge is that this therapy may cause significant side effects for many patients who decide that this is the therapy they want to choose. The trade off there might be that there might be protection from taking this therapy over time.
But it'll be an individualized decision and it will be important for patients to have really clear and individual conversations with their allergist.
OK. So what does it actually do?
Palforzia, which is the only approved therapy for peanut desensitization, is designed to create a situation in which patients who accidentally have a small amount of peanut will not react as severely. But the challenge is that in the process of receiving the therapy in small amounts, allergic reactions can occur to the therapy itself.
And so, if you have a situation where a child is known to be allergic to peanut, and is avoiding peanut, and has not had any reactions for the past few years, the risk that that child will have an allergic reaction to the therapy itself is about 14 to 15 per cent.
And so, you can go from a situation where children are simply avoiding what they're allergic to, to a situation where the child is now receiving therapy for anaphylaxis to this daily therapy they're taking at home. And so, that's a real problem because for many patients they might be better off just simply avoiding it.
But on the other hand, if you have a situation where there's very high anxiety, and worry, then the idea that a child could take this therapy, and if they accidentally get exposed to a peanut there would be some level of protection against a severe reaction, can be very attractive.
So no one should be deluded to thinking that this therapy is going to allow their kid to have a peanut butter sandwich.
No, that's exactly right. I mean, that was the hope, right?
If you could design the perfect therapy what you would design is a therapy for peanut allergy that didn't have side effects, but that's not what we have yet.
Can you just walk us through this pill Palforzia? It's not just a matter of taking a pill, is it? It's a treatment. So just walk us through the stages.
Palforzia is a standardized peanut flour that needs to be introduced in very small amounts and the idea is that there are very small graded steps.
A patient and their family would come into the clinic and they would receive a small amount of this peanut protein, this peanut flour, and they would be observed for a period of time to make sure there's no severe reaction. And if there's not a reaction, they would continue to build up in small, incremental doses until they reach the equivalent of about one peanut.
But these doses and steps will require multiple visits back to the allergist office, usually in about two week intervals. And the build up phase will probably take somewhere between three and six months. But once patients are built up to this, what we would call a maintenance dose of daily therapy, they would need to continue to take this daily therapy every day.
And the challenge is that every day they take that therapy there is some risk of having a reaction to the peanut flour.
Importantly, with Palforzia, it's critical that these therapies only be used under the supervision of a board certified allergist and that no one try to proceed with home brew sorts of oral immunotherapy without the supervision of an allergist.
I think some parents might be forgiven if they think, well, wait a second. This sounds familiar. They may have allergists who already do oral immunotherapy in their clinics under supervision. They prescribe doses of peanut flour, which costs about six dollars for a one pound bag. So one allergist was saying to NPR that "they're just packaging up what we already do in a gold-plated capsule." Is there truth to that?
That's definitely an argument that I've heard. I think there are some advantages to an FDA-approved product.
The advantage that we have is we actually know what the side effect rates of this therapy are. We have large trials. We know what the effectiveness of a therapy is. But as far as what the actual product is — I think you make a very valid point — that it may not be very different from what you can get at your grocery store.
The counter argument there, though, is that Palforzia is standardized for a very particular major peanut protein component, which is called Ara h2. But that means that with Palforzia the idea is that you know that each time you're getting the dose it's the same amount of peanut protein versus peanut protein off the shelf may have variable quantities.
This is such a debilitating and dangerous allergy, isn't it, especially for children, and so why do you think at this point there isn't a better treatment or even a cure?
So debilitating and dangerous — I think it's important to have conversations around that because part of the reason that folks will be drawn to this therapy is because of fear and because of the impact on quality of life.
One of the conversations I often have with with kids I'm taking care of is I ask them, "What do you think is more dangerous — having a bicycle or having a peanut allergy?" And when patients stop and think about that more times than not they say a bicycle. And in reality, having a bicycle and having a peanut allergy have about the same risk — about one in a million.
I think it's very important to keep risk in perspective. You know, having a peanut allergy can be dangerous. But it can be managed and it's important to be empowered and not live in fear.
This type of therapy may be the exact right therapy you're looking for, but you're going to have to look twice because there are risks and there are benefits.
Written by Katie Geleff and John McGill. Interview produced by Katie Geleff. Q&A has been edited for length and clarity.