PRT120 Peanut Oral Immunotherapy Demonstrates Durable 3-Year Remission in Phase 2b Study
Key Insights
PRT120 peanut oral immunotherapy achieved sustained remission in over 90% of children at 3-year follow-up, with patients safely consuming peanuts without daily dosing or moderate-to-severe reactions.
Children who achieved remission showed superior outcomes compared to those only desensitized, with no moderate or severe reactions requiring epinephrine among 53 remission patients versus 16.7% and 11.1% rates in desensitized participants.
The PPOIT-003 long-term study findings earned an EAACI Prize for outstanding research, highlighting remission as the optimal treatment goal over desensitization.
Prota Therapeutics (search)' experimental peanut oral immunotherapy PRT120 has demonstrated sustained remission in children with peanut allergy (search) three years after treatment completion, with over 90% of patients in remission maintaining regular peanut consumption without moderate or severe reactions. The findings from the Phase 2b PPOIT-003 long-term study earned recognition with a European Academy of Allergy and Clinical Immunology (search) (EAACI) Prize at the organization's 2025 Annual Congress in Glasgow.
The award-winning research, presented by lead investigator Paxton Loke, PhD, from Murdoch Children's Research Institute, revealed striking differences between patients who achieved remission versus those who were only desensitized. Among 53 children who achieved remission, no moderate or severe reactions occurred during three years of ad libitum peanut consumption. In contrast, 16.7% and 11.1% of desensitized participants experienced moderate and severe reactions respectively, with 6.1% requiring rescue adrenaline injectors.
Novel Approach Targets Durable Remission
PRT120 represents the first oral immunotherapy specifically developed to induce durable remission of peanut allergy (search) through immune response modulation that suppresses peanut-specific IgE (search) production. The therapy employs a proprietary short-term dosing regimen involving rapid build-up followed by high-dose maintenance over 18 months, distinguishing it from existing approved therapies that require indefinite daily dosing.
"To see children remain protected and able to eat peanuts freely three years after completing PRT120 treatment, without the anxiety of significant reactions or the demands of indefinite dosing, demonstrates the potential of this approach to transform care for peanut allergy (search)," said Loke.
In the original Phase 2b trial, PRT120 delivered what the company describes as best-in-class efficacy, with nearly 80% of patients tolerating the equivalent of 20-25 peanuts at treatment completion. The therapy became the first to demonstrate sustained protection after treatment discontinuation.
Long-term Follow-up Reinforces Remission Benefits
The three-year follow-up data builds on previously reported outcomes showing over 95% of children who achieved remission safely consuming peanuts at the two-year mark. The sustained protection without ongoing treatment burden contrasts sharply with desensitized patients, who struggled with regular consumption, experienced higher rates of adverse reactions, and were more likely to discontinue treatment.
"This recognition from EAACI underscores the clinical importance of remission as an endpoint," Loke noted. The award represents the second major recognition for Prota's research, following an award at the 2023 GALEN GA2FA Annual Conference for their two-year follow-up findings.
Professor Mimi Tang, PhD, director of the Allergy Translation Centre at MCRI and scientific founder of Prota, emphasized the clinical significance of the sustained outcomes. "Children in remission after Prota's unique short-duration oral immunotherapy and dosing regimen, PRT120, not only maintain protection without daily dosing, but also enjoy a better quality of life and freedom from ongoing treatment burden."
Phase 3 Trial Planned for 2026
The encouraging long-term data sets the stage for upcoming four- and five-year follow-up analyses, which Tang indicated continue to show persistence of remission and sustained quality of life improvements. Prota plans to initiate a Phase 3 clinical trial evaluating PRT120 in the United States next year.
"With its differentiated dosing regimen and demonstrated durability of effect, PRT120 has the potential to offer children and families the freedom to live without the daily fear and treatment burden of peanut allergy (search)," said Guillaume Pfefer, PhD, director of Prota Therapeutics (search).
The research was conducted in partnership with MCRI and involved study teams at Perth Children's Hospital and Adelaide Women's and Children's Hospital. Tang acknowledged the collaborative effort and expressed gratitude to the families who participated in the trial, noting that such work has only been possible through these partnerships.