Allergy Therapeutics plc

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

PROTECT Phase I/IIa trial meets primary safety endpoint at highest planned dose

·      PROTECT trial achieves final dosing of the minimum anticipated number of patients at the highest planned treatment dose

·      Preliminary safety data from 48 participants demonstrate that a 2000-fold increase in dose of VLP Peanut has been safe and well tolerated

·      Data from the second interim biomarker analysis in peanut-allergic patients receiving the highest doses is expected in Q1 2026, following the previously announced initial interim analysis data from lower doses

09 December 2025 Allergy Therapeutics (AIM: AGY), the fully integrated commercial biotechnology company specialising in allergy immunotherapies, today announces that its Phase I/IIa PROTECT trial has completed final dosing of the minimum required number of patients at the highest planned treatment dose, meeting the trial's primary safety endpoint. Preliminary safety data from 48 participants demonstrate that a 2000-fold increase in dose from the starting dose has been safe and well tolerated, including in both peanut-allergic patients and healthy participants.

As previously reported, a benign safety profile of VLP Peanut is supported by the observed dose-dependent reduction in wheal size following skin prick testing for the two lowest doses evaluated. In addition, peanut-allergic patients showed a strong immune-protective dose response in biomarkers at low cumulative doses, with dose-dependent suppression of basophil activation and a dose-dependent increase in protective Ara h2 IgG, aligned with a dose-dependent reduction in IgE binding to B-cells.

Data from healthy participants support the proposed mechanism of action of VLP Peanut. In addition, preliminary blinded biomarker data collected three months after last dosing of peanut allergic patients indicate a sustained biomarker response. The Company intends to carry out a second interim analysis in peanut-allergic patients receiving the highest doses in due course.

The trial is currently progressing to deliver the planned group unblinded skin prick test and biomarker results, together with longer-term biomarker and scheduled safety assessments for up to one year after last dosing.

Preparations are also underway for the Phase IIb trial, with the doses of VLP Peanut being informed by the combined safety and efficacy information generated in the PROTECT trial.

Manuel Llobet, Chief Executive Officer of Allergy Therapeutics, commented: ""The PROTECT trial has now reached a key regulatory milestone with the primary safety endpoint achieved at the highest planned treatment dose. Safety and tolerability at these dose levels remain supportive, reinforcing our confidence in the short-course approach underpinning VLP Peanut.

"As we move into the final stages of follow-up and biomarker assessment, our focus is on translating these data into the next phase of clinical development. We thank all participants, investigators and clinical teams involved in the study."

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 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 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.