Notice of Completion of Final Observation Day in Phase I Clinical Trial of Allergy Vaccine

FunPep Co., Ltd. (Headquarters: Ibaraki City, Osaka; Representative Director and President: Toshimi Miyoshi) announced today the completion of the final observation day (LPO (Last Patient Out)) for the last patient in its Phase I clinical trial (hereinafter referred to as "this trial") for the allergy vaccine (antibody-inducing peptide FPP004X) currently under development for hay fever.

Moving forward, we will proceed with the collection and analysis of all data from this trial, and preliminary results are scheduled to be disclosed in the third quarter of 2026 (July-September).

This trial primarily evaluates the safety, tolerability, and immunogenicity (antibody production) of FPP004X when FPP004X or a placebo is repeatedly administered (intramuscularly) to healthy adults and patients with seasonal allergic rhinitis (hay fever).

This trial consists of Part 1, targeting healthy adults, and Part 2, targeting patients with seasonal allergic rhinitis (hay fever). Part 1 was conducted in three stages: a low-dose cohort (two administrations at 4-week intervals) and a high-dose cohort (two administrations at 4-week intervals or three administrations at 4-week intervals). In Part 2 (three administrations at 4-week intervals), a pollen exposure chamber was used, in which pollen was artificially dispersed at a constant concentration, to confirm the reaction to Japanese cedar pollen.

Hay fever is an allergic disease characterized by an excessive allergic reaction to pollen from plants such as Japanese cedar and cypress. Typical symptoms include sneezing, runny nose, nasal congestion, and itchy eyes.

According to a nationwide epidemiological survey in Japan, the prevalence *i* in 2019 was 42.5% for hay fever overall and a high 38.8% for Japanese cedar pollinosis, which affects a large number of patients. Both figures have increased by more than 10% compared to 10 years prior (2008). The market for medicines (oral drugs) for allergic rhinitis, including hay fever, was approximately 170 billion JPY in 2019 *ii*.

Therefore, the government views hay fever, often called a national disease and a persistent problem for many citizens, as a societal issue and is working on countermeasures.

The antibody-inducing peptide FPP004X is an allergy vaccine expected to have therapeutic effects by inducing the production of antibodies against IgE (Immunoglobulin E) in the body. IgE is a type of antibody that works to eliminate foreign substances that enter the body, and when it binds to causative substances (allergens) such as pollen, it triggers allergic reactions. FPP004X is expected to have a sustained effect on various allergic diseases by causing immune cells to produce anti-IgE antibodies for a certain period. Leveraging this characteristic, our company aims to provide a highly convenient new treatment option for patients, with hay fever as the primary indication, by administering it before pollen season to alleviate symptoms throughout the season.

Regarding FPP004X, an option agreement was concluded with Shionogi & Co., Ltd. in March 2024, and the company holds an option right to acquire exclusive research, development, and commercialization rights for all diseases worldwide.

*i* Atsushi Matsubara et al. National Epidemiological Survey of Nasal Allergy 2019 (Comparison with 1998, 2008): Preliminary Report - Targeting ENT doctors and their families -. Jpn J Otorhinolaryngol 2020;123:485-490.

*ii* Ministerial Meeting on Hay Fever Countermeasures "Hay Fever Measures (Ministry of Health, Labour and Welfare)"