Brand name for processed peanut flour, AR101 (now called PTAH – PeanuT Arachis Hypogaea), used for peanut immunotherapy.
Available in Scotland at Glasgow private clinic – see www.peanutimmunotherapy.scot for details.
Defatting process supports storage conditions, pharmaceutical processing for protein content and consistency, and may remove some of the peanut flavour. But you can just buy defatted peanut protein on the internet, so main advantage is that it is prepacked (and licensed).
NHS England has approved it for use but only in 600 children in the first year, then 2000 the year after.
AR101 trial found adults 18+ did not develop any tolerance, so 17yrs is cut off. 67% managed 600mg challenge (4 peanuts) “with no more than mild symptoms”.
Aim is not to “cure” peanut allergy, though – but to “mitigate against severe reactions” (ie anaphylaxis) if you accidentally come into contact with peanut. You need to continue taking a regular dose of Palforzia or else “real world” peanut (eg peanut M&Ms) every day life long, and otherwise you need to continue avoiding peanut – most children (aged 4-17) will achieve tolerance of 2 peanuts, but many will react to a larger dose, and we don’t know how long tolerance lasts (especially if doses are missed).
Initial trial was in 4+ but latest data (2023) shows just as effective in 1- 4yrs too – 73.5% (n=98), tolerated a single dose of ≥600 mg peanut protein at exit challenge [6.3% in the placebo group!]Treatment-related adverse events, which were mild to moderate, were experienced by 75.5% (but also 58.3% of placebo-treated participants). 3 treatment-related systemic allergic reactions, “none of which were severe or serious” seen in 2 PTAH-treated participants (2%).
BSACI Palforzia guidelines
A Delphi consensus study, involving a panel of clinicians but also parents. 4 of the authors declared conflict of interest, having received fees from the manufacturer.
States that “clinical capacity should not constrain access to this treatment” – this is not one of the consensus statements, however. In supplement, advises on how to approach local commissioners (in England) for additional funding, saying that Palforzia may now be considered an essential part of paediatric allergy service delivery –
- Write document with planned numbers and costs
- Write a SOP
- Liaise with pharmacy lead for High Cost Drugs
- Integrated medications optimisation committee (IMOC) are responsible for formulary additions, high cost drug use, and also track NICE approved medications and their implementation
- Approved funding pathway would be tariff based, or else adjustment to block contract.
- Often a Blueteq form will be required
Seems to be saying that Palforzia treatment should be seen as one aspect of overall allergy management, and that individual needs may justify its use even when resources are limited.
This fits with the Canadian (CSACI) 2020 guidelines which say “Individuals vary with respect to their level of comfort with risk as well as their perception of the extent of benefit derived from a treatment. Thus, the decision to pursue OIT should be left to the well-informed patient as much as clinically possible, rather than based on external criteria.” And the inability of clinicians to reliably predict risk and severity of future reactions means “OIT should be available to all patients who wish to receive it”.
One of the consensus statements states “Parents of children with peanut allergy who are aged at least 4 years of age should be informed that peanut OIT is an option for management and be offered a discussion with a HCP who understands the child and their family’s context.”
Another emphasises shared decision making training, guidance and support. Table 5 includes an extensive list of discussion topics including goals of therapy, health beliefs (eg susceptibility to reactions, severity), bullying, stigma, impact of asking about ingredients, having reactions, need for medications, wider family/cultural support or influence, “fear of missing out” (FOMO).
In other words, shouldn’t be up to whim of clinician to decide whether to talk about it, or whether to offer it.
It is also clearly stated that participants with peanut allergy alone and those with other food allergies were keen to undertake OIT – which highlights that avoidance of peanut is a particular burden on families. Some centres in the UK are undertaking OIT for multiple nuts simultaneously but this is clearly much more challenging for families and clinicians.
The 3 month Updosing phase of treatment required considerable changes to family routines, with families reporting “putting aside 6 months to prioritise successful updosing”, impacting on sports, clubs, holidays, exams and other family activities.
Highlights that 24hr helplines were rarely used, and families would have been keen for treatment even if only offered email support during office hours. This clearly reduces the burden of one aspect of providing the service.
Although most patients will achieve tolerance of the equivalent of 2 peanuts, points out that those who discontinue treatment often perceive that they have “failed” in some sense. Debrief is therefore important (but also expectations, clearly).
Another consensus statement was around converting to “real world” peanut rather than continuing with the commercial product – all the focus group participants were in favour of real world peanut, as it highlights the sense of progress, and it feels “normal” rather than medical.
Each patient should be reviewed on at least one occasion around 12 months after achieving stability on either real world peanut or Palforzia maintenance before considering discharge – since it takes at least 6 months to achieve stability, this emphasizes that even where tolerance is successfully achieved, further support and review is essential.
(CSACI also specify appropriate equipment and infrastructure – see OIT equipment list PDF)