Allergy Therapeutics plc

("Allergy Therapeutics", "ATL" or the "Group")

Positive biomarker results from the PROTECT Phase I/IIa trial following achievement of the primary safety endpoint

The comprehensive panel of biomarkers of efficacy demonstrated the strong immunomodulating response which was highly consistent in all peanut allergic subjects after treatment with VLP Peanut:

·      Significant reduction in basophil sensitivity for peanut and Ara h2 compared to baseline

·      Ara h2 binding to the effector B-Cells (IgE-Fab) demonstrated a relevant downward dose response, reaching statistical significance for the highest dose of VLP Peanut

·    A clear dose-dependent increase seen in Ara h2-specific IgG across the dose ranges tested reaching statistical significance

·      An absolute reduction in wheal diameter after skin prick testing with peanut was observed

4 March 2026 Allergy Therapeutics (AIM: AGY), the fully integrated commercial biotechnology company specialising in allergy immunotherapies, today announces consistent biomarker results from its Phase I/IIa PROTECT trial, supporting the strong immunomodulating potential of the product.

Increasing doses of VLP peanut were associated with a reduction compared to baseline in basophil sensitivity for whole peanut extract and Ara h2. Notably, at the highest dose, the reduction reached 376% (p=0.003) and 489% (p=0.04) for peanut and Ara h2 compared to placebo respectively.

The functional assay measuring the main allergen (Ara h2) binding to the effector B-Cells (IgE-Fab) demonstrated a relevant downward dose response, reaching statistical significance for the highest dose of VLP Peanut.

Both these positive outcomes in basophil sensitivity and IgE-FAB were associated with a strong dose-response in Ara h2-specific IgG change from baseline when comparing each of the cumulative doses with placebo, reaching statistical significance for all but the lowest dose compared to placebo reaching p=0.0005 for the highest dose.

A reduction in wheal diameter was observed 1-month post treatment while placebo wheal diameter slightly increased consistent with the beneficial immunological shift seen across the full panel of efficacy biomarkers.

Mo Shamji, Professor in Immunology and Allergy, Imperial College London, commented: "The inhibitory effect observed in the IgE-Fab data assay is remarkable, especially given the short treatment duration of three injections over two-three months. Similar outcomes may only be achieved after approximately 12 months daily administration of oral immunotherapy."

Alexandra Santos, Chair in Paediatric Allergy, King's College London, commented: "I am delighted to have served as the Chair of the Safety Review Committee throughout this trial with VLP Peanut. I was impressed with the consistent dose response seen across all biomarker endpoints, along with a consistent wheal size reduction during skin prick testing following treatment. The dose-dependent reduction in basophil activation after VLP Peanut is particularly relevant as this biomarker is highly representative for food challenge outcome, which will serve as primary endpoint for the upcoming Phase II/III trials. It is very exciting to be part of the clinical development journey of VLP Peanut, which has the potential to change the current treatment paradigm for peanut allergic patients, offering both a safe and efficacious treatment modality, possibly after three or four injections only."

Manuel Llobet, Chief Executive Officer of Allergy Therapeutics, commented: "These interim analysis results from the PROTECT trial demonstrate clinical proof of concept of the product. In addition to its supportive safety profile, these biomarker results highlight the transformational clinical potential with the unique opportunity to offer a potent immunomodulating treatment option with a limited number of injections, not currently offered by oral immunotherapy nor monoclonal options currently available or under development.

"We are greatly encouraged to see recent health agency expert opinion panels aligning with our strategy to provide solutions that the patients in the US and beyond deserve. Coupled with the supportive safety and tolerability data we've already shown, the team is very keen on progressing to the Phase IIb trial to establish dose-range and efficacy via food challenge. VLP peanut and the underlying technology platform remain key to helping the millions of patients who live with the consequences of peanut and other food allergies."

More information about the PROTECT trial can be found on ClinicalTrials.gov under the identifier NCT05476497.

This announcement contains inside information for the purposes of the UK Market Abuse Regulations.

- ENDS -

Allergy Therapeutics

Manuel Llobet, Chief Executive Officer

Shaun Furlong, Chief Financial Officer

+44 (0)1903 845 820

Cavendish Capital Markets Limited (Nominated Adviser and Broker)

Geoff Nash /Giles Balleny/ Seamus Fricker

Nigel Birks - Life Science Specialist Sales

+44 (0)20 7220 0500

ICR Healthcare

Mary-Jane Elliott / David Daley / Davide Salvi

+44 (0)20 3709 5700

[email protected]

Notes for editors:

About Allergy Therapeutics

Allergy Therapeutics is an international commercial biotechnology company, headquartered in the UK, focussed on the treatment and diagnosis of allergic disorders, including aluminium free immunotherapies that have the potential to cure disease. The Group sells proprietary and third-party products from its subsidiaries in nine major European countries and via distribution agreements in an additional ten countries. For more information, please see www.allergytherapeutics.com.

About the PROTECT Trial

The PROTECT trial completed final dosing in December 2025 and consisted of 3 parts (skin prick testing with VLP Peanut in peanut allergic patients and dose escalation of VLP Peanut in both healthy subjects and peanut allergic patients. In this latter part, patients were randomized to receive 3 subcutaneous doses of VLP Peanut, approximately 4 weeks apart. Overall, a 2,000-fold dose escalation was implemented from the starting dose, without reaching a relevant safety signal, meeting the trial's primary safety objective.

The trial is evaluating the safety and tolerability, and exploring preliminary proof of efficacy, of the Group's innovative, short-course peanut allergy drug candidate, VLP Peanut.

The trial is currently progressing to deliver longer-term biomarker and scheduled safety assessments for up to one year after last dosing and preparations are underway for the Phase IIb trial, with the chosen doses of VLP Peanut being informed by the combined safety and efficacy information generated in the PROTECT trial.

The PROTECT trial, across multiple clinical trial sites in the US, is being conducted in both healthy subjects and peanut allergic patients and consists of Part A and Part B. Part A involved subcutaneous immunotherapy (SCIT) dosing in healthy subjects (Group A1) and skin-prick testing in peanut allergic patients (Group A2). Part B of the clinical trial is double-blind, placebo-controlled and in patients with peanut allergy. This biomarker efficacy analysis included 4 and 7 patients who received VLP Peanut for each of the four cumulative dose groups and placebo, respectively.