Teijin : Pharma to Receive $5 Million Milestone Payment from Bioprojet for Initiating Phase 1 Clinical Trial of Narcolepsy Drug Candidate

Tokyo, November 27, 2025 --- Teijin Pharma Limited, the core company of the Teijin Group's healthcare business, announced today that it will receive in Q4 2025 a milestone payment of $5 million USD from Bioprojet, a French pharmaceutical company. This payment is a provision of the exclusive 2024 license agreement between Teijin Pharma and Bioprojet, which granted Bioprojet the global rights to develop, manufacture and commercialize a candidate compound for the treatment of narcolepsy. It is being triggered by Bioprojet's initiation of a Phase I clinical trial in Europe, following successful progress in research and development.

Narcolepsy is a sleep disorder that significantly disrupts daily life. It is characterized by excessive daytime sleepiness and cataplexy (sudden muscle weakness), often caused by a deficiency in orexin, a neurotransmitter that regulates the sleep-wake cycle. Current treatments aim to reduce daytime sleepiness by promoting wakefulness through medication.

Bioprojet, founded in 1982, is engaged in research, development and commercialization of drugs in the fields of neurology, immunology, allergy and rare diseases like narcolepsy. Its flagship product, pitolisant (brand name: WAKIX Ⓡ), is a histamine H3 receptor antagonist widely used internationally as a treatment for narcolepsy.

Teijin Pharma determined that licensing the candidate compound to Bioprojet, which has a proven track record in developing and marketing narcolepsy treatments, would best contribute to improving the quality of life for patients worldwide.

Following the Phase 1 clinical trial, Bioprojet will continue clinical development, aiming for market launch at a future date in accordance with the terms of the agreement.

Teijin (TSE: 3401) is a technology-driven global group with two core businesses: high-performance materials and healthcare solutions. Established in 1918 as Japan's first rayon manufacturer, Teijin today comprises some 150 companies employing 20,000 people. Teijin is committed to its Purpose, "Pioneering solutions together for a healthy planet." Teijin works together with employees and external partners to achieve its Long-Term Vision, "To be a company that supports the society of the future." Teijin posted consolidated revenue of JPY 1,005.5 billion and total assets of JPY 1,061.3 billion in the fiscal year ending March 31, 2025.

Corporate Communication Department Teijin Limited

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