For families living with peanut allergy, daily life is shaped by constant vigilance—reading labels, avoiding social risks, and managing the ever-present fear of accidental exposure.
While advances in treatment have helped reduce the risk of severe reactions, the search continues for therapies that can deliver more lasting freedom and confidence. Current approved therapies typically require lifelong daily dosing and continued strict avoidance, leaving the day-to-day burden and anxiety of food allergy largely unchanged.
This has led researchers to ask a more ambitious question: can the immune system be recalibrated to achieve durable tolerance and, ultimately, remission?
Technology Networks spoke with Prof. Mimi Tang, an immunologist allergist at the Murdoch Children’s Research Institute and the scientific founder of Prota Therapeutics, to discuss the science behind PRT120, an investigational peanut oral immunotherapy designed to induce larger and longer-lasting immune change.
Rhianna-lily Smith (RLS):
Science Writer and Editor
Technology Networks
Rhianna-lily is a Science Writer and Editor at Technology Networks. She holds an honors degree in biomedicine from the University of East Anglia and a masters degree in microbiology. Before joining Technology Networks she researched maternal health and the microbiome.
How does PRT120 work, and how is it different from existing peanut allergy treatments?
Mimi Tang, PhD (MT):
Clinician Scientist
Prota Therapeutics
Professor Mimi Tang is a clinician scientist with more than 30 years of experience in pediatric allergy and immunology.
PRT120 is designed to redirect the immune system away from an allergic response to peanuts and toward a state of remission. Achieving remission requires both switching off allergic pathways and supporting the development of new tolerance pathways, which could be disease-modifying.
PRT120 uses a defined treatment regimen that combines rapid dose escalation with high-dose maintenance. This structured approach appears to engage the immune system differently from what has been shown for a low-dose oral immunotherapy. In our research, PRT120 drives a large and sustained reduction in peanut-specific IgE, the antibody central to allergic reactions, and shifts peanut-reactive T cells from an allergic Th2 profile to a more regulated, tolerance-associated state. These findings are consistent with the immunologic “rewiring” observed in our mechanistic studies as well as the durable clinical protection seen in our previous trials.
We believe that this is very different from currently approved treatments.
Existing products provide temporary desensitization and protect against small amounts of peanut allergen—typically up to a cumulative dose of ~1,000 mg, or about 4 peanuts, during a food challenge. Because this protection is modest and short-lived, patients must remain on indefinite daily maintenance dosing, and they must continue strict peanut avoidance.
With PRT120, we potentially see durable, high-level protection. In clinical studies, children tolerated a cumulative dose of ~5,000 mg of peanut—roughly 20 peanuts—at the end of treatment. Many children were able to achieve remission and were subsequently able to eat peanuts without the burden of lifelong daily therapy or strict avoidance, reflecting a fundamentally different clinical outcome driven by the way PRT120 resets the allergic immune response.
It is important to note that PRT120 is an investigational therapy currently being evaluated in clinical trials and has not been approved by any regulatory authority.
RLS:
Science Writer and Editor
Technology Networks
Rhianna-lily is a Science Writer and Editor at Technology Networks. She holds an honors degree in biomedicine from the University of East Anglia and a masters degree in microbiology. Before joining Technology Networks she researched maternal health and the microbiome.
Why is it important to move beyond temporary desensitization toward longer-lasting tolerance?
MT:
Clinician Scientist
Prota Therapeutics
Professor Mimi Tang is a clinician scientist with more than 30 years of experience in pediatric allergy and immunology.
Living with a food allergy is a constant daily burden for families. Temporary desensitization can reduce the likelihood of a reaction and the severity of one, but it does not change the underlying immune dysregulation or the fundamental reality of living with food allergy. Patients must remain on continuous maintenance dosing and must also continue strict avoidance, meaning the emotional and practical burden persists. The anxiety does not go away.
Any break in adherence increases the risk of reactions, and we consistently see how challenging it is for families to maintain dosing over long periods. Protection with temporary desensitization also shows day-to-day variability, and reactions can still occur with illness, exercise, or inconsistent allergen content in foods. This ongoing uncertainty leads to significant emotional stress and reduced quality of life.
This is why the scientific field is increasingly focused on whether it is possible to recalibrate the immune system so that it remains less reactive even after treatment stops. Achieving this kind of durable tolerance would provide fuller, longer-lasting protection and meaningfully reduce the broader pressures of living with food allergy—moving families from constant vigilance towards more assurance and a confident way of life.
RLS:
Science Writer and Editor
Technology Networks
Rhianna-lily is a Science Writer and Editor at Technology Networks. She holds an honors degree in biomedicine from the University of East Anglia and a masters degree in microbiology. Before joining Technology Networks she researched maternal health and the microbiome.
What have you seen so far in your clinical studies that suggests PRT120 may help achieve remission?
MT:
Clinician Scientist
Prota Therapeutics
Professor Mimi Tang is a clinician scientist with more than 30 years of experience in pediatric allergy and immunology.
In our clinical studies, those children who achieve challenge-defined remission after 18 months of treatment with PRT120 can stop treatment and freely introduce peanut into their diets. These children typically eat moderate to large amounts of peanuts at least once a week without reactions. Between two five years post-treatment, children in remission experienced no severe reactions and no rescue epinephrine use, and they reported meaningful improvements in quality of life that go well beyond what has been documented for low-dose desensitization-based therapies.
In the Phase 2b study, 73% of treated children tolerated a cumulative 5 g of peanut (roughly 25–30 peanuts) at the end of the 18-month treatment period. Approximately 51% retained this high level of protection after 2 months off treatment, indicating they had achieved remission. The durability of the response is particularly notable:
After 2 years, more than 95% of children who achieved remission were eating peanuts freely.
After 3 years, over 90% of those still in follow-up continued regular ingestion, typically 1–2 times per week.
We are currently analyzing robust outcomes at four to five years following treatment.
Our long-term follow-up of children who completed the Phase 2b study has shown that children in remission have substantial and sustained quality-of-life gains, which were not observed for the children who were desensitized without achieving remission. While PRT120 remains an investigational therapy, these durable, off-treatment quality-of-life improvements have not been demonstrated with other approved treatments that desensitize without achieving remission.
RLS:
Science Writer and Editor
Technology Networks
Rhianna-lily is a Science Writer and Editor at Technology Networks. She holds an honors degree in biomedicine from the University of East Anglia and a masters degree in microbiology. Before joining Technology Networks she researched maternal health and the microbiome.
What have your mechanistic studies taught you about how PRT120 induces durable remission?
MT:
Clinician Scientist
Prota Therapeutics
Professor Mimi Tang is a clinician scientist with more than 30 years of experience in pediatric allergy and immunology.
Our mechanistic work suggests that PRT120 does more than temporarily blunt reactivity; it appears to reset the underlying allergic immune response. With PRT120’s high-dose and potentially finite regimen, we see large and sustained reductions in peanut-specific IgE, the antibody that drives peanut allergy. Importantly, this suppression persists well beyond the end of treatment, which is very different from what’s been observed with standard desensitization approaches.
At the cellular level, gene expression analyses of peanut-specific CD4⁺ T cells show that children in remission undergo a shift from a Th2-dominant “allergic” profile toward a more regulatory, tolerogenic network.
In other words, the immune system is not just dampened; it is rewired to respond differently to peanuts.
Together, the marked and durable reduction in peanut-specific IgE, alongside this Th2-to-tolerogenic shift in T cells, provides a coherent biological explanation for why the protection we see with PRT120 can be durable and off-treatment, rather than dependent on ongoing daily dosing. PRT120 is still investigational, but these mechanistic insights strongly support its potential to induce true remission rather than temporary desensitization.
RLS:
Science Writer and Editor
Technology Networks
Rhianna-lily is a Science Writer and Editor at Technology Networks. She holds an honors degree in biomedicine from the University of East Anglia and a masters degree in microbiology. Before joining Technology Networks she researched maternal health and the microbiome.
Could the same approach used in PRT120 be applied to other food allergies in the future?
MT:
Clinician Scientist
Prota Therapeutics
Professor Mimi Tang is a clinician scientist with more than 30 years of experience in pediatric allergy and immunology.
We do have early clinical data in egg and milk allergy showing that high-dose, rapid escalation regimens can also lead to remission, which suggests the underlying concept is not limited to peanuts.
That said, each allergen has its own biology and practical considerations, so dedicated studies would be necessary to understand how broadly this approach can be applied. Currently, our clinical development is focused on peanuts, and further work is required before considering expansion to other food allergies.
