Palforzia for treating peanut allergy in children and young people

Peanut allergen powder (Palforzia) is an allergen extract for oral immunotherapy (1,2)

• Peanut (Arachis hypogaea) Allergen Powder-dnfp (PAHAP; Palforzia) is the first oral immunotherapy of its kind for the desensitization of peanut allergy in children and should be used along with a peanut-avoidant diet
  • approved for initiation in individuals 4 to 17 years of age with a confirmed diagnosis of peanut allergy and may be continued for maintenance in those 4 years of age and older
    
    
• exact mechanism of PAHAP has not been determined
  • it is a complex biologic drug of peanut protein manufactured from defatted peanut flour with a well-defined allergen profile
  • similar to other oral immunotherapies, this allergenic protein is initially ingested in very small quantities and then incrementally increased using a structured 3-phase dosing approach
    • consists of 3 sequential phases:
      
      
      • 1) initial dose escalation
        • initial dose escalation is administered under the supervision of a health care professional in a health care setting in case there is a need to manage potentially severe allergic reactions, including anaphylaxis.
      • 2) up-titration; and
      • 3) maintenance
• adverse effects
  • most common adverse reactions are abdominal pain, vomiting, nausea, oral pruritus, oral paresthesia, throat irritation, cough, rhinorrhea, sneezing, throat tightness, wheezing, dyspnea, pruritus, urticaria, ear pruritus, and anaphylactic reaction (which may be life-threatening)
    
    
• contraindications, warnings and precautions
  • contraindicated in patients with uncontrolled asthma and in those with a history of eosinophilic esophagitis or other eosinophilic gastrointestinal disease
  • should be used with caution in patients with controlled asthma
    • should be temporarily withheld when a patient is experiencing an acute exacerbation
  • if a patient develops clinical features suggestive of eosinophilic esophagitis then PAHAP should be discontinued
  • if a patients develop chronic or recurrent local gastrointestinal allergic symptoms
    • then dose modification or discontinuation of treatment may be required

A review notes over half of patients who completed treatment were able to tolerate a dose of >=1000 mg peanut protein given as part of food challenge test without developing dose-limiting allergic symptoms (3)

• also notes that this needs to be weighed against risk of allergic reactions

NICE state (4):

• Palforzia is recommended, within its marketing authorisation, as an option for treating peanut allergy in children aged 4 to 17. It can be continued in people who turn 18 while on treatment. Palforzia should be used with a peanut-avoidant diet
  
  
• the NICE committee state that "..clinical trial evidence shows that Palforzia improves tolerance to peanut protein compared with placebo when precise amounts are used in a food challenge test. And it is likely that Palforzia improves people's quality of life once they are having a stable dose. People are likely to need to take Palforzia or regularly include peanuts in their diet to maintain the tolerance they gained. It is uncertain how long people would continue treatment, but few are likely to need to continue Palforzia for the rest of their lives..."

Reference:

1. Erlich D. Peanut Allergen Powder (Palforzia) for Peanut Allergy. American Family Physician. 2022 Jan;105(1):20-21. PMID: 35029941
2. Smith SS, Hilas O. Peanut (Arachis hypogaea) Allergen Powder-dnfp: The First FDA-approved Oral Immunotherapy for Desensitization of Peanut Allergy in Children. J Pediatr Pharmacol Ther. 2021;26(7):669-674. doi:10.5863/1551-6776-26.7.669.
3. Palforzia for oral desensitisation to peanut in allergic children. Drug and Therapeutics Bulletin 2022;60:166-169.
4. NICE (February 2022). Palforzia for treating peanut allergy in children and young people