The therapy, developed by Aimmune Therapeutics, is designed to reduce the incidence and severity of allergic reactions, including anaphylaxis, after accidental peanut exposure in children age 4 through 17 who have a confirmed diagnosis of a peanut allergy. Because accidental exposure with even a fraction of a single peanut can trigger a life-threatening allergic reaction for a child with a severe allergy, many children and parents must be vigilant in virtually every aspect of daily life. “It’s very exciting that we now have something. Current treatment for a peanut allergy is avoiding peanuts,” says Alice Hoyt, MD, an allergist at Independence Family Health Center, part of the Cleveland Clinic Health System in Ohio. “One of the most difficult parts for families to manage food allergies is the anxiety associated with that treatment plan of simply avoidance, which is more easily said than done,” says Dr. Hoyt. Many families want the level of protection that this medication can provide, she adds.
Peanut Allergies Are on the Rise
If you’ve been noticing more nut-free camps and classrooms, it’s not your imagination. Peanut allergies have increased substantially in the past few decades. The number of children with the potentially life-threatening allergy has risen from 0.4 percent in 2007 to a current estimate of 2.2 percent of all children and adolescents in the United States, according to a study published in November 2018 in the Annals of Allergy, Asthma & Immunology. In the late 1990s, the allergy community realized that peanut allergies were increasing, says Hoyt. Expert opinion, which was not necessarily based on evidence, recommended that parents hold off on introducing peanuts into children’s diets. The idea was to wait until their immune systems would be ready to tolerate it. That practice actually led to a rise in children with more-severe peanut allergies, says Hoyt. In a study published in February 2015 in The New England Journal of Medicine, investigators noticed that although allergies existed in Israel, peanut allergies were less common. “They did some investigating and found that many infants in that country would snack on what’s called Bamba, which is a puff with a lot of peanut protein in it. Then the thought became: Maybe early introduction encourages the immune system to become more tolerant,” says Hoyt. Based on the results of the study, it’s now recommended that peanut foods be introduced to infants as young as 4 to 6 months old to prevent allergies, says Hoyt. If children have severe eczema or if they’re allergic to eggs, they’re considered at a high risk for a peanut allergy, and any introduction to peanut protein should be done under the guidance of an allergist, says Hoyt.
What Is Palforzia?
Palforzia isn’t designed to cure a peanut allergy. It decreases the frequency and severity of an allergic reaction in the event of peanut exposure. It’s an oral immunotherapy that actually contains peanut flour. “When allergists talk about immunotherapy, we mean building up tolerance to an allergen,” says Hoyt. Allergists have been doing this for decades to help with pollen allergies, says Hoyt. “When we give people allergy shots, over time we’re slowly injecting them with higher and higher concentrations of a pollen until we reach a maintenance dose based on evidence,” she says. Over time, the body can build up a tolerance. The same principle is at work with oral immunotherapy for a peanut allergy, she explains. In that way, the science behind Palforzia isn’t new. “For the past 10 years or so, some allergists have been using peanut flour or peanut butter with the same concept of starting with a very, very low dose and slowly building up a patient’s tolerance,” says Hoyt. In the case of Palforzia, patients take increasing amounts of the therapy (which introduces the tested proprietary amount of peanut) over a period of about six months or longer until their immune system begins to tolerate larger amounts of peanuts. At that point, the person continues to take a daily therapeutic dose to maintain the desensitization effect.
Palforzia’s Path to Approval
The FDA committee voted 7 to 2 to approve the efficacy data and 8 to 1 to approve a risk evaluation and mitigation strategy to minimize the risk for patients. Part of the plan requires that parents of children prescribed Palforzia therapy have an injectable EpiPen or similar device ready to use in case any allergic reaction occurs. The vote was based in part on the results of the phase 3 PALISADE clinical trial, which were published in November 2018 in The New England Journal of Medicine. At the beginning of the trial, 551 participants were given Palforzia or a placebo. People taking the immunotherapy started with a 0.5 milligram (mg) dose of peanut protein, which was gradually increased to 6 mg. When adverse reactions occurred, the study allowed for changes to the dosing schedule. At the end of the trial, 67 percent of the people taking Palforzia were able to tolerate a dose of peanut protein equivalent to about two peanut kernels, compared with 4 percent of the placebo group. The application for Palforzia’s approval is currently under review by the FDA, with a review action date of late January 2020, according to a statement by Aimmune.
Palforzia Offers Hope to Those Who Live in Fear
The biggest concern with a peanut allergy is anaphylaxis, which can cause impaired breathing, swelling of the throat, and a sudden drop in blood pressure, according to the American College of Allergy, Asthma & Immunology. “That’s one reason a therapy like this is a huge deal,” Hoyt says. Being able to ingest the equivalent of two peanuts is very significant because it provides a threshold that many allergists refer to as “bite proof,” says Hoyt. Bite-proof means that if a child takes a bite of something and realizes it has peanuts in it, they might not have an extreme reaction, and possibly, they may even be able to tolerate it, she says. “This medication can provide a level of protection and peace of mind, although it won’t take away all of the risks,” she says.
A Personal Account of a “Transformative Experience”
Tessa Grosso knows the value of peace of mind. She is the daughter of Kim Yates Grosso, the chief executive officer and founder of Latitude Food Allergy Care, a specialty clinic in Redwood City, California, that is focused on food allergy care. She shared her story with the Institute for Clinical and Economic Review (ICER), an independent watchdog on drug pricing in the United States. Grosso described taking Palforzia as “the most important, valuable, and transformative experience in my life.” Gross said that her allergy caused isolation, depression, anxiety, and fear for herself and everyone close to her. “Patients like me don’t want to eat a PB&J, but we do want to sit with other kids at lunch,” Grosso told the committee. “Something so simple is a privilege that you cannot understand unless you have walked in our shoes.”
Do the Benefits of Palforzia Justify the Costs and Risks?
Not everyone is convinced that Palforzia is the answer for children with a peanut allergy. David Rind, MD, ICER’s chief medical officer, said in a statement that the committee’s review left them unconvinced that the long-term benefits outweigh the short-term risk. Dr. Rind points out that Palforzia is associated with increased allergic reactions and use of epinephrine, and that caregivers and patients must remain vigilant about avoiding peanuts even while on desensitization therapy. According to an industry analysis, it’s estimated that Palforzia will carry a price tag of about $4,200 a year, and it’s unclear how much insurance companies would cover and for how long. Still, Hoyt believes that the therapy can do a lot of good for many families. “I think a big benefit is that it can help reduce the anxiety that can come with peanut allergy,” she says.
