Teijin : Pharma and Aska Pharmaceutical Enter Joint Research Agreement to Accelerate Discovery of Novel Small-Molecule Drug Candidates for Gynecological Diseases

Tokyo, February 17, 2026 --- Teijin Pharma Limited, the core company of the Teijin Group's healthcare business, announced today that it has entered into a joint research agreement with Tokyo-based Aska Pharmaceutical Co., Ltd. to jointly develop novel small-molecule drug candidates targeting gynecological diseases. Aska Pharmaceutical is a specialty pharmaceutical company with extensive expertise in obstetrics and gynecology.

Under this agreement, the two companies will collaborate to accelerate the early-stage drug discovery process aimed at identifying innovative therapeutic candidates. The development of small-molecule drugs typically begins with screening large numbers of compounds to identify "hit" compounds that interact with specific molecular targets. The molecular structure of these hits is then optimized to achieve the desired efficacy, pharmacokinetic properties, and safety profiles required for drug development.

Teijin Pharma is enhancing the sophistication and efficiency of compound discovery and optimization by leveraging computer-aided drug design (CADD) technologies and artificial intelligence-based drug discovery approaches. Through highly accurate molecular design using simulations and predictive models, the company has established a research platform that shortens drug discovery timelines and improves the probability of success.

Aska Pharmaceutical has built a drug discovery foundation rooted in real-world clinical needs. The company places particular emphasis on addressing unmet medical needs in women's healthcare and has developed a broad portfolio of products that support women throughout different stages of life.

By combining Teijin Pharma's CADD and AI-driven drug discovery technologies with Aska Pharmaceutical's deep expertise in gynecological diseases and pharmacological evaluation, the two companies aim to increase the speed and success rate of the drug discovery process. They share a vision of addressing unmet needs in gynecological care and delivering innovative treatments that help improve quality of life.

Based on its corporate philosophy, "Contribute toward the improvement of people's health and progress in society through the development of innovative products," ASKA specializes in three key therapeutic areas: internal medicine (gastroenterology and thyroid), obstetrics and gynecology, and urology, and is engaged in business centered on new drugs with the aim of becoming a competitive specialty pharma company. ASKA

will solidify its position as a competitive specialty pharma company and contribute to people's health to meet the changing needs of society, while building on our contributions through pharmaceutical products.

URL: https://www.aska-pharma.co.jp/

Corporate Planning Department, ASKA Pharmaceutical Co., Ltd.

E-mail: [email protected]

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

E-mail: [email protected]