Please note this article and the authors’ comments are not intended to provide medical advice. Only a healthcare provider can diagnose and treat food allergies, including peanut allergy and all questions should be directed to a healthcare provider.
This article is supported by Stallergenes Greer. The medical professionals Dr. Stephen Tilles and Dr. Anne-Marie Irani are paid medical advisors to Stallergenes Greer and authors of the POSEIDON study. The content reflects their views.
Peanut allergy currently affects approximately 2% of the U.S. pediatric population1-2. Compared to other food allergies, peanut allergy is associated with higher rates of morbidity due to accidental exposure, with the severity of reactions in some patients, despite strict allergen avoidance efforts highlighting the continuous need for safe and effective therapies.
Palforzia® [Peanut (Arachis hypogaea) Allergen Powder-dnfp] is the first and only U.S. Food and Drug Administration (FDA) approved oral immunotherapy treatment (OIT) for the mitigation of allergic reactions, including anaphylaxis that may occur with accidental exposure to peanut for children ages 1 through 17 years with a confirmed peanut allergy3.
IMPORTANT SAFETY INFORMATION (summary)3:
Palforzia® is not a cure for peanut allergy. Patients must maintain a peanut-free diet while taking Palforzia® and carry injectable epinephrine at all times. Palforzia® should not be taken by patients with uncontrolled asthma, or a history of eosinophilic esophagitis (EoE) or other eosinophilic gastrointestinal disease. Palforzia® is only intended to treat children with a peanut allergy and is not effective against other food allergies a child may have. Palforzia® does not treat allergic reactions and should not be given during an allergic reaction.
Palforzia® can cause severe allergic reactions called anaphylaxis that may be life-threatening and can occur at any time during Palforzia® therapy3.
Palforzia® is a prescription medication that is only available through a special safety program called the Palforzia® Risk Evaluation and Mitigation Strategy (REMS) Program3. This program ensures that Palforzia® is prescribed and administered in a way that helps manage risks and keep patients as safe as possible.
Please see full Important Safety Information at the end of this article. Full Prescribing Information, including Boxed WARNING, is available at Palforzia.com
Palforzia® was initially approved by the FDA in 2020 for ages 4 through 17 years and in 2024 received an expanded indication for children ages 1 through 3 years. Stallergenes Greer, a global leader in allergy therapeutics, announced the launch of Palforzia® in the US for toddlers, ages 1 through 3 years, in early March of this year [2025].
Palforzia® is an oral peanut allergen powder treatment that allows for monitored exposure to consistent and precise amounts of peanut protein every day, which is intended to gradually increase the child’s tolerability to peanuts3. Palforzia® is made from peanuts and is carefully tested to ensure it contains the right key peanut proteins (Ara h 1, Ara h 2, & Ara h 6) responsible to help train the child’s immune system to gradually reduce sensitivity to peanuts and requires ongoing adherence management in consultation with an allergy specialist3-4.
The FDA approval for the expanded indication of Palforzia® is based on data from the Phase 3 POSEIDON (Peanut Oral Immunotherapy Study of Early Intervention for Desensitization) study published in the New England Journal of Medicine Evidence in 2023. The study evaluated the efficacy and safety of Palforzia® in peanut- allergic children aged 1 to 3 years, of which at the conclusion the study endpoints were met, and safety was demonstrated3,5-6.
Palforzia® was proven in clinical studies, including POSEIDON, to help reduce the severity of allergic reactions, including anaphylaxis, that may occur with accidental exposure to peanut in children ages 1 through 3 years3,5. In POSEIDON after one year of treatment, 74% of toddlers tolerated 600 mg of peanut protein (about 2 peanuts) (vs 6.3% who received placebo) with no more than mild allergic symptoms and approximately 80% of toddlers tolerated 300 mg of peanut protein (about 1 peanut) (vs 22.9% on placebo) with no more than mild allergic symptoms3,5.
An exploratory analysis of the 1-year POSEIDON clinical trial suggests that toddlers treated with Palforzia® did not show the same increases in peanut-specific IgE observed in placebo-treated children5-6. Palforzia® has not been studied in toddlers (1–3 years) beyond one year and is indicated for the mitigation of allergic reactions, including anaphylaxis that may occur with accidental exposure to peanut3. The long-term variation of peanut sIgE levels in toddler patients has not been studied with Palforzia® and is not indicated to prevent disease progression or sensitization in children ages 1 through 17 years3,5-6.
In the following Q&A with Allergic Living’s Gwen Smith, allergists Dr. Stephen Tilles and Dr. Anne-Marie Irani offer their insights into treatment of peanut allergy, early intervention with Palforzia® in toddlers, POSEIDON study findings and more.
Dr. Stephen Tilles is a Clinical Professor of Medicine at the University of Washington and a consultant for the nonprofit FARE. Dr. Anne-Marie Irani is Professor Emerita in the division of Pediatric Allergy & Immunology at the Children’s Hospital of Richmond in Virginia. Dr. Tilles and Dr. Irani are consultants for Stallergenes Greer and have been compensated for their participation. Both Dr. Tilles and Dr. Irani are authors of the POSEIDON study.
Q&A with Dr. Anne-Marie Irani and Dr. Stephen Tilles
Gwen Smith: Before we begin discussing Palforzia®, I want to ask you, Dr. Tilles, when it comes to treating peanut allergy, what is different about the toddler age (ages 1-3 years)?
Dr. Stephen Tilles: So, the toddler age range is a critical window for peanut allergy treatment. At the toddler stage (ages 1-3 years), the immune system is still taking shape and we’re learning that it’s much more amenable to being changed7-8.
You can actually think of peanut allergy as the evolution of three types of disease. In one, there are infants destined to become peanut allergic, but this may be able to be prevented through early peanut introduction as shown by the (Learning Early About Peanut Allergy) LEAP study7.
The second group includes toddlers who already have peanut allergy but whose immune systems appear more adaptable.6,8. And then there’s the older children, starting at age 4 years and older, where it seems their immune system tends to be more committed8.
Dr. Anne-Marie Irani: Recent studies of peanut allergy in the toddler age group (1 to ≤3 years), have shown similar results for untreated peanut-allergic toddlers, in which their peanut-specific IgE (the allergy antibody to peanut) level increased significantly between the ages of 1 to 2 years and 2 to 3 years6,8 while the immune system is still developing.
Early intervention with a peanut allergy treatment between the ages of 1 to 3 years, may be an option to help prevent progression of peanut sensitivity in younger children6,8 and should be considered as part of the discussion between the physician and patient and/or caregiver as part of the shared decision-making process.
Dr. Tilles: It is something we’re passionate about as allergists, but it is not just allergists who should understand more about this potential treatment window for toddlers. It is important for those who are just starting to become aware of the importance of early introduction and the role of early intervention.
Parents who suspect their toddler may have a peanut allergy should speak with their toddler’s pediatrician and seek a referral to an allergist for proper allergy testing and, if a peanut allergy is confirmed, to discuss possible treatment options.
Pivotal Trial: POSEIDON
Gwen Smith: I want to pivot to dive deeper into the POSEIDON clinical trial. It was a phase 3, randomized, double-blind, placebo- controlled clinical trial that involved 146 toddlers, ages 1 through 3 years, in North America and Europe over 12 months3,5. Ninety-eight participants were treated with Palforzia® and 48 participants received placebo3,5. At the start of the trial, how much peanut could children consume before having a reaction?
Dr. Irani: At the start of the POSEIDON trial, the participants underwent a food challenge, and the average maximum amount of peanut protein they reacted to was 30 milligrams, which 1/10th of a peanut3,5.
Gwen Smith: How did that compare to what you saw at the end of the trial?
Dr. Irani: The primary endpoint of the study was the proportion of participants who were able to tolerate 600 milligrams – about 2 peanuts – of peanut protein with no more than mild allergy symptoms3,5. About 74% of the toddlers (ages 1 to 3 years) treated with Palforzia® were able to reach this endpoint at the end of 12 months3,5. By comparison, the placebo treated participants showed only 6.3% were able to tolerate 600 milligrams of peanut protein3,5.
The study also showed that about 80% of Palforzia®-treated toddler participants were able tolerate 300 milligrams of peanut protein with no more than mild allergy symptoms, a secondary endpoint of the study3,5.
Additionally, the POSEIDON study also showed that about 62% of the Palforzia® treated toddlers were able to tolerate the highest dose measured during the exit food challenge3,5. This exploratory endpoint was 2,000 milligrams or 2 grams of peanut (about 6 to 8 peanuts)3,5. Comparatively, only 2% of participants in the placebo group could tolerate the same amount of peanut protein3,5.
Dr. Tilles: In the POSEIDON study, both Palforzia®-treated and placebo-treated toddlers (ages 1 to 3 years) had their peanut-specific IgE (peanut sIgE) levels measured at the start and end of the trial5-6. An exploratory analysis of participants’ peanut sIgE levels during the 12-month trial, showed toddlers treated with placebo had a significant increase in their peanut sIgE levels, while toddlers treated with Palforzia® showed no increase in peanut sIgE levels6. Initiating Palforzia® at an earlier age (toddlers, ages 1-3 years) may help to prevent progression of peanut-specific IgE6.
[Palforzia® is indicated for the mitigation of allergic reactions, including anaphylaxis that may occur with accidental exposure to peanut3. Palforzia has not been studied in toddlers (ages 1-3 years) beyond one year3,5. The long-term variation of peanut- specific IgE levels in toddler patients has not been studied with Palforzia® and it is not indicated to prevent disease progression or sensitization in children ages 1 through 17 years3,5-6.]
Importance of Safety
Gwen Smith: When taking a new medication, it is important to be aware of possible side effects. Can you share the side effects and safety information about Palforzia® in the toddler age group (ages 1 to 3 years)?
Dr. Irani: The most common side effects of Palforzia® in toddlers (ages 1-3 years) were cough, sneezing, runny nose, nasal congestion, throat irritation, wheezing, stomach pain, vomiting, diarrhea, itchy mouth, pain in the throat, hives, rash, itchy skin, inflammation of the skin around the mouth3,5. Additional symptoms in young children may include inconsolable crying, excessive sleepiness, and drawing the legs up to the stomach10.
Palforzia® can cause severe allergic reactions, called anaphylaxis, that may be life-threatening3. If while taking Palforzia® a patient experiences a severe allergic reaction, they should stop taking Palforzia®, administer their prescribed epinephrine immediately, and get emergency medical help3.
In the POSEIDON study, anaphylactic reactions were reported in 8.2% of Palforzia®-treated toddlers (8 subjects) and 8.3% of placebo-treated toddlers (4 subjects)3,5. Of the 9 anaphylactic reactions reported, in 8 children receiving Palforzia®, only 3 were attributed to Palforzia®, all occurring during the Up-Dosing phase3,5. The remaining 6 reactions were due to exposure to other food allergens3,5. No participants discontinued the study due to anaphylactic reaction3-5.
It is important for patients and their caregivers to also understand that:
- Palforzia® does not treat allergic reactions and should not be given during an allergic reaction3.
- Palforzia® is only intended to treat children with a diagnosed peanut allergy; it is not effective against other food allergies3.
- Patients must maintain a peanut-free diet while on Palforzia® and carry epinephrine at all times3.
Palforzia® is a prescription medication that is only available through a special safety program called the Palforzia® Risk Evaluation and Mitigation Strategy (REMS) Program3. This program ensures that Palforzia® is prescribed and administered in a way that helps manage risks and keep patients as safe as possible.
It is important to talk to your toddler’s allergy specialist if you have any questions about Palforzia® or for medical advice about possible side effects.
Understanding the Palforzia® Treatment
Gwen Smith: Let’s talk specifically about the Palforzia® treatment protocol. For instance, a family has consulted with their toddler’s physician, a peanut allergy has been confirmed, and the physician has chosen to prescribe Palforzia® for the toddler patient. What does the treatment protocol look like?
Dr. Irani: The first day of treatment is the Initial Dose Escalation, which is a one-time initiation dose appointment, given in a REMS certified doctor’s office3. The toddler is given gradually increased doses throughout the appointment starting at 0.5 milligrams up to 3 milligrams and is monitored for about 20 to 30 minutes in between each dose for any signs of an allergic reaction, except for the last dose which is monitored for 60 minutes3,5. If the child is able to tolerate the Initial Dose Escalation, they will return to the doctor’s office within 4 days and begin the Up-Dosing step of the Protocol3.
The Up-Dosing step is an approximately 6-month treatment plan3. In which the first dose of each new Up-Dose level is given in the doctor’s office and the toddler is monitored for at least 60 minutes3. Should the child tolerate that first dose of the new dose level, the doctor will then ask the parent to continue the toddler on that dose level every day at home for the next 2 weeks3. The parent should receive counseling from the doctor on signs of allergic reactions and should monitor the child for at least an hour after giving the daily Palforzia® dose3. The patient will then return to the doctor’s office approximately every 2 weeks to be assessed for a new Up-Dose level3.
If the toddler is able to tolerate all levels of the Up-Dosing step, the doctor will continue the toddler on a maintenance dose of 300 mg of Palforzia® taken daily as Maintenance therapy3. The Maintenance step requires continued dosing to maintain the treatment effect and help sustain the toddler’s reduced sensitivity to peanut allergens3. It will be up to your child’s individual doctor regarding the length of Maintenance, however during the POSEIDON clinical trial the Maintenance treatment was 6 months3,5.
The treatment process may be adapted by the toddler’s doctor to the toddler’s unique needs at the doctor’s discretion, which may include modifying the dosing amount and/or schedule as needed for patients who experience an allergic reaction, or for practical patient management reasons based on their clinical judgment3.
It is important that patients who are prescribed Palforzia® and their caregivers know that the child must maintain a peanut-free diet, carry their prescribed epinephrine while on Palforzia® and understand that allergic reactions, including anaphylaxis, may occur at any time during the Palforzia® treatment3. Should a patient experience a reaction, the toddler’s doctor will treat accordingly, which may include modifying and/or discontinuing the Palforzia® treatment3.
It is important to speak with your toddler’s individual doctor if you have any questions about Palforzia® and if prescribed to follow the doctor’s instructions for your toddler’s individual treatment.
What’s Unique About Palforzia®
Gwen Smith: Can you share with our readers why an FDA-approved product like Palforzia® is important?
Dr. Tilles: The peanut flour used to manufacture Palforzia® is sourced from the same agricultural source as commercial peanut9. However, the similarity to other types of peanut flour ends there9. What distinguishes Palforzia® is its consistent allergen potency9.
The majority of batches of peanut intended for Palforzia® are rejected as they are not suitable for processing and the most common reason for lot rejection of peanut flour from these peanut fields is their inconsistent potency of the allergenic proteins9. Meaning, unlike other types of peanut flour, Palforzia® is manufactured in a consistent and controlled process to ensure that the potency of clinically relevant protein allergens is precise and consistent across product lots4,9. Any batches not meeting the criteria for Palforzia® are rejected.
Awareness of Palforzia® for Toddlers
Gwen Smith: With Palforzia® treatment available for physicians to treat toddlers, what do each of you hope to see from this newly available treatment for toddlers?
Dr. Irani: To me, the most important thing is the awareness that Palforzia® treatment is also available for toddlers, ages 1 to 3 years3. It would be great for more parents to be aware of this therapy.
Dr. Tilles: Awareness is so important, both for parents and for general practitioners. Until recently, the standard of care for food allergy – peanut included – was simply strict avoidance only. I think the awareness of this therapy can help to shift that discussion, so that if a toddler is diagnosed with a peanut allergy, this FDA-approved treatment [Palforzia®] can be part of a shared decision-making conversation between the doctor and the parent/caregiver of the child. More than anything, I hope that growing awareness empowers parents with choices.
Please see below for Important Safety Information, including Boxed Warning. Full Prescribing Information and Medication Guide can be found on Palforzia.com
IMPORTANT SAFETY INFORMATION
WARNING: ANAPHYLAXIS: Palforzia® can cause anaphylaxis, which may be life-threatening and can occur at any time during Palforzia® therapy. Prescribe epinephrine, instruct and treat patients on its appropriate use, and instruct patients to see immediate medical care upon its use. Do not administer Palforzia® to patients with uncontrolled asthma. Dose modifications may be necessary following a anaphylactic reaction. Observe patients during and after administration of the Initial Dose Escalation and the first dose of each Up-Dose level, for at least 60 minutes.
Palforzia® is available only through a restricted program called the Palforzia® REMS.
CONTRAINDICATIONS: Palforzia® is contraindicated in patients with uncontrolled asthma, or with a history of eosinophilic esophagitis and other eosinophilic gastrointestinal diseases.
WARNINGS AND PRECAUTIONS: Anaphylaxis: Palforzia® can cause anaphylaxis, which may be life-threatening. Palforzia® is only available through a restricted program under a Risk Evaluation and Mitigation Strategy (REMS) called the Palforzia® REMS because of the risk of anaphylaxis. Only prescribers, healthcare settings, pharmacies, and patients certified and enrolled in the REMS Program can prescribe, receive, dispense or administer Palforzia®. Anaphylaxis has been reported during all phases of Palforzia® dosing, including Maintenance and in subjects who have undergone recommended Up-Dosing and dose modification procedures. Do not initiate Palforzia® treatment in a patient who has had severe or life-threatening anaphylaxis within the previous 60 days. Palforzia® may not be suitable for patients with certain medical conditions that may reduce the ability to survive anaphylaxis, including, but not limited to, markedly compromised lung function, severe mast cell disorder, or cardiovascular disease. In addition, Palforzia® may not be suitable for patients taking medications that can inhibit or potentiate the effects of epinephrine. All Initial Dose Escalation doses and the first dose of each Up-Dosing level must be administered under observation in a certified healthcare setting. Patients may be more likely to experience allergic reactions following Palforzia® administration in the presence of cofactors such as exercise, hot water exposure, intercurrent illness (e.g., viral infection) or fasting. Other potential cofactors may include menstruation, sleep deprivation, nonsteroidal anti- inflammatory drug use, or uncontrolled asthma. Patients should be proactively counseled about the potential for the increased risk of anaphylaxis in the presence of these cofactors. If possible, adjust the time of dosing to avoid these cofactors. If it is not possible to avoid these cofactors, consider withholding Palforzia® temporarily.
Asthma: Uncontrolled asthma is a risk factor for a serious outcome, including death, in anaphylaxis. Ensure patients with asthma have their asthma under control prior to initiation of Palforzia®. Palforzia® should be temporarily withheld if the patient is experiencing an acute asthma exacerbation. Following resolution of the exacerbation, resumption of Palforzia® should be undertaken cautiously. Re-evaluate patients who have recurrent asthma exacerbations and consider discontinuation of Palforzia®.
Eosinophilic Gastrointestinal Disease: Discontinue Palforzia® and consider a diagnosis of eosinophilic esophagitis in patients who experience severe or persistent gastrointestinal symptoms, including dysphagia, vomiting, nausea, gastroesophageal reflux, chest pain, or abdominal pain.
Gastrointestinal Adverse Reactions: Gastrointestinal adverse reactions were commonly reported in Palforzia®-treated subjects, and dose modification should be considered for patients who report these reactions. For severe or persistent gastrointestinal symptoms, consider a diagnosis of eosinophilic esophagitis.
ADVERSE REACTIONS: The most common adverse reactions reported in subjects ages 1 through 3 years treated with Palforzia® (incidence ≥5%) are cough, sneezing, rhinitis, nasal congestion, throat irritation, wheezing, abdominal pain, vomiting, diarrhea, oral pruritus, oropharyngeal pain, urticaria, rash, pruritus, and perioral dermatitis. The most common adverse reactions reported in subjects ages 4 through 17 years treated with Palforzia® (incidence ≥5% and at least 5% greater than placebo) are abdominal pain, vomiting, nausea, oral pruritus, oral paresthesia, throat irritation, cough, rhinorrhea, sneezing, throat tightness, wheezing, dyspnea, urticaria, anaphylactic reaction, and ear pruritus.
ABOUT STALLERGENES GREER
Headquartered in Baar (Switzerland), Stallergenes Greer is a global healthcare company specializing in the diagnosis and treatment of allergies through the development and commercialization of allergen immunotherapy products and services. Supported by more than 100 years of expertise and innovation, our products are available for patients in over 40 countries. For more information, visit www.stallergenesgreer.com.
1. Bilaver LA, Chadha AS, Doshi P, O’Dwyer L, Gupta RS. Economic burden of food allergy: A systematic review. Ann Allergy Asthma Immunol 2019;122:373–80 e1. 2.Gupta RS, Springston EE, Warrier MR, et al. The prevalence, severity, and distribution of childhood food allergy in the United States. Pediatrics 2011;128:e9–17. 3.PALFORZIA [package insert]. Lenoir, NC; Greer Laboratories, Inc. 4.Fernandez-Rivas M, et al. Allergy 2022;73:991–1003. 5.Du Toit G, et al. NEJM Evid. 2023;2(11):EVIDoa2300145. 6.Du Toit G, et al. [supplemental appendix]. NEJM Evid. 2023;2(11):EVIDoa2300145. 7.Du Toit G, et al. N Engl J Med. 2016;374(15):1435-1443. 8.Jones, Stacie M et al. Efficacy and safety of oral immunotherapy in children aged 1-3 years with peanut allergy (the Immune Tolerance Network IMPACT trial): a randomised placebo- controlled study. Lancet (London, England) vol. 399,10322 (2022): 359-371. doi:10.1016/S0140-6736(21)02390-4. 9.Leonard SA, et al. Frontiers in Allergy. 2022;3:1004056. 10.PALFORZIA [Medication Guide]. Lenoir, NC. Greer Laboratories, Inc.
Related Reading:
Full POSEIDON Study in NEJM Evidence
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