G308 Phase III Year 2 Patient Screening Starts

• G308 paediatric study progresses to planned second year of recruitment and will evaluate short-term efficacy and safety
• Industry first subcutaneous allergen-specific immunotherapy trial designed to evaluate both short and long-term efficacy and safety in paediatric subjects
• Short-term safety data from the first year expected to be announced in Q4 2025

30 October 2025 Allergy Therapeutics (AIM: AGY), the fully integrated commercial biotechnology company specialising in allergy immunotherapies, announces that the first subjects have been screened for inclusion in the second year of the Phase III G308 trial that aims to evaluate both the short and long-term efficacy and safety of Grass MATA MPL in paediatric subjects.

The screening and randomisation period is planned to be completed by early Q1 2026 to allow all scheduled injections of Grass MATA MPL to be administered prior to the commencement of the 2026 grass pollen season.

The second year of recruitment in the G308 trial aims to achieve a similar number of randomised participants as the first year, in which 190 participants were randomised. This will allow a full analysis of the short-term safety and efficacy results of the G308 study in Q4 2026, with short-term safety data from the first year expected to be announced in Q4 2025. Patients selected for the long-term extension will progress to a further three years of active treatment or placebo. This will be followed by two years of treatment-free follow-up, after which the long-term primary efficacy & safety will be evaluated.

The G308 study has been designed to ensure that only a minority of patients will receive long-term treatment of placebo (~8-13% probability), which is an important improvement from the EMA standard design (50% probability) and will enable the majority of paediatric patients to receive long-term active treatment.

Manuel Llobet, CEO of Allergy Therapeutics, commented: "The commencement of screening in the second year of our Phase III G308 trial builds upon our commitment to addressing the unmet needs of the paediatric population in grass allergy. Overall we have invested over $100M in clinical development in grass allergy to date and combined with our successful adult trials, this long-term trial will help us in our aim to provide children affected by grass allergies with an alternative treatment journey that is less burdensome compared to taking tablets daily."

Allergy Therapeutics

Manuel Llobet, Chief Executive Officer

Shaun Furlong, Chief Financial Officer

Cavendish Capital Markets Limited (Nominated Adviser and Broker)

Geoff Nash /Giles Balleny/ Seamus Fricker

Nigel Birks - Life Science Specialist Sales

ICR Healthcare

Mary-Jane Elliott / David Daley / Davide Salvi

About Grass MATA MPL

Grass MATA MPL is being developed as a subcutaneous immunotherapy product for the treatment of allergic rhinitis and/or rhinoconjunctivitis.

Grass MATA MPL contains an extract of 13 grass pollens modified with glutaraldehyde to form allergoids that reduces the reactivity with immunoglobulin E (IgE) antibodies without a reduction in other important immunological properties, such as T-cell reactivity. The allergoid is adsorbed to microcrystalline tyrosine as a depot adjuvant system formulation. Monophosphoryl lipid-A (MPL), is included as an adjuvant to increase the immunogenic effect of the immunotherapy and to enhance the switch from an allergen specific helper T-cell Type 2 (Th2) to helper T-cell Type 1 (Th1) like immune response.