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

Funpep Co., Ltd. (Headquarters: Ibaraki City, Osaka; Representative Director and President: Toshimi Miyoshi) is pleased to announce the completion of the final observation day (LPO (Last Patient Out)) for the last patient in the Phase I clinical trial (hereinafter referred to as "this trial") for its 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 (intramuscular injection) 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 a three-stage configuration: 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, where a certain concentration of pollen was artificially dispersed, was used to confirm the reaction to cedar pollen.

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

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

For this reason, the government views hay fever, which is said to be a national disease and continues to trouble many citizens, as a social problem and is working on countermeasures against hay fever.

Antibody-inducing peptide FPP004X is an allergy vaccine that is 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 an allergic reaction. Since FPP004X induces immune cells to produce anti-IgE antibodies for a certain period, sustained effects against various allergic diseases are expected. Leveraging this characteristic, our company aims to provide a new, convenient treatment option for patients, with hay fever as the primary indication, by administering it before the 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 Otolaryngologists and their Families -. Jibi 2020;123:485-490.

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