Palforzia: New peanut immunotherapy drug reduces severe reactions

Peanut allergy affects around 2% (or 1 in 50) of children in the UK. Instances of peanut allergies have been increasing in recent years, resulting in a range of allergic reactions from mild symptoms to life-threatening anaphylaxis. Palforzia treatment, available at Evelina London Children’s Hospital, aims to treat patients aged 4-17 with peanut allergy.

What is Palforzia?

Peanut allergy is a common food allergy and has a significant effect on the quality of life of the patient and their family. Whilst fortunately rare, peanut is one of the most common causes of severe anaphylaxis and, despite this, there are currently no available treatments to completely eliminate an adverse reaction in allergic patients.

Evelina London Children’s Hospital was one of the centres involved in the international trial of Palforzia, a new peanut immunotherapy drug. The drug has been developed to increase the threshold at which patients will react to peanut and reduce the severity of the symptoms due to accidental peanut exposure.

“Palforzia is not a cure for peanut allergy,” explains Dr Elizabeth Powell, consultant in paediatric allergy and joint lead for peanut oral immunotherapy at Evelina London. “We’re trying to protect patients from accidental exposures, not turn them into peanut eaters.” Patients are still advised to avoid peanuts and to carry their autoinjector devices with them whilst on treatment, and after having finished the treatment programme.

Palforzia is currently the only NICE-approved immunotherapy for a food allergy and has been licensed for use in children aged 4-17. It is accessible through both NHS and private routes at Evelina London, which is home to the largest paediatric allergy service in Europe.

How does Palforzia work?

Palforzia works by giving the patient a small amount of peanut protein with each day. The oral immunotherapy drug comes in powder form in a capsule or sachet and is mixed with semi-solid foods such as yoghurt, so that it can be thoroughly coated, reducing oral symptoms.

The Palforzia treatment programme consists of three stages: an initial dose escalation step, up-dosing stage and a maintenance stage. The up-dosing stage involves gradually increasing the amount of peanut protein given until the maximum dose of 300mg is reached.

“There are a total of 11 dose levels and, depending on how well the patient tolerates Palforzia, it typically takes 4.5-6 months to complete this up-dosing stage,” says Dr Powell. Each time the dose is increased, the patient will take the first dose of it in hospital. This supervision is necessary with each up-dose due to the risk of an allergic reaction.

The maintenance stage involves the patient continuing to consume 300mg of Palforzia a day, usually for around 6-18 months. After this stage, the aim is for the patient to transition to the same amount of peanut protein as real-world peanut each day to maintain tolerance.

What contraindications are there?

Palforzia is not suitable for every patient, so a thorough assessment appointment is required to ensure that Palforzia fits with a patient’s health and lifestyle. This will take into account fitting Palforzia into their daily life, any other medical conditions, as well as the patient’s mental wellbeing. If needed, our team can refer patients for psychological support before beginning Palforzia treatment.

The patient’s other allergies and any gastrointestinal symptoms will also be taken into consideration. Around half of the Palforzia patients we see at Evelina London have other allergies like hay fever or conditions such as asthma or eczema which need to be well-controlled, or can increase the risk of allergic reactions with the Palforzia doses.

What is the long-term outlook for Palforzia patients?

“At the moment, we’re planning for patients to be on the maintenance dose for up to 6-18 months,” explains Dr Powell. Patients will then go onto real-world peanuts, eating approximately one to one and a half peanuts a day with dietetic advice from the Palforzia team. Four hours of dedicated dietician support is included in our Palforzia treatment package.

The aim is then that all patients continue to eat this small amount of peanut daily for the rest of their lives. “At present, the data supports ongoing consumption as there is a significant risk of losing tolerance if the treatment is stopped,” explains Dr Powell.

Clinical trials in peanut immunotherapy have consistently shown the efficacy of treatment. In the largest trial with Palforzia (Palisade), 372 children (4-17 years old) received Palforzia and 124 received placebo. Of participants taking Palforzia, 76% tolerated 300mg (roughly one peanut), 67% tolerated 600mg, and 50.3% tolerated 1000mg. Of the placebo group, the respective tolerance levels for these amounts of peanut were 8%, 4% and 2.4%.

Of those that continued Palforzia to 12 months (excluding those who dropped out), 96% of participants could tolerate 300mg of peanut protein, 84% could consume 600mg, while 63% could tolerate at least 1000mg with no more than mild symptoms.

When to refer to us

Palforzia is suitable for patients with a confirmed peanut allergy. They can be started on treatment from the age of four years old. Patients will need to begin their up-dosing period by their fifteenth birthday, and so can be referred to us for treatment before this point.

Although Palforzia is not a cure for peanut allergy, it can help to prevent severe symptoms and increase the threshold to react to peanut on accidental exposure. Patients’ whose daily activities are limited by a peanut allergy would benefit from a referral to learn more about their suitability for Palforzia.

Dr Elizabeth Powell

Consultant in paediatric allergy

Dr Elizabeth Powell specialises in food and drug allergies in childhood. She is the lead for drug allergy and joint lead for peanut oral immunotherapy at Evelina London and is an active member of the British Society of Clinical Allergy and Immunology.

Get in touch

For more information on our Palforzia treatment programme, please contact our customer services team.