Sosei Heptares Doses First Subject in Phase 1 Trial with HTL0033744, an EP4 Agonist for Inflammatory Bowel Disease

HTL0033744 has been designed by Sosei Heptares to promote mucosal healing and resolve inflammation in people with IBD Tokyo, Japan and Cambridge, UK, 21 March 2024 – Sosei Group Corporation (“Sosei Heptares” or “the Company”; TSE: 4565) announces it has dosed the first subject in a Phase 1 trial evaluating its novel EP4 receptor agonist, HTL0033744 (HTL’744) for the treatment of Inflammatory Bowel Disease (IBD), a therapeutic area where there remains significant unmet need for millions of people worldwide. HTL’744 is a potent, selective and gut-restricted prostaglandin EP4 receptor agonist that has been uniquely designed to bring clinical benefit by accelerating the healing of damaged epithelial mucosa and suppressing exaggerated gut inflammation, with minimal systemic exposure to avoid adverse events. This approach is widely recognized to promote deeper remission and offer better long-term clinical outcomes1,2. HTL’744 aims to address the significant unmet need of people with IBD that do not achieve satisfactory disease control. Current treatments for IBD typically achieve remission rates of less than 25%, and the safety profile of these drugs mean that they require careful monitoring. The Phase 1 trial is a first-in-human randomized, double-blind study to assess the safety, pharmacokinetics and effects on pharmacodynamic biomarkers of single and multiple ascending doses of HTL’744 in adult healthy volunteers and people with Crohn’s disease to generate proof of mechanism. The trial will be conducted in the UK and initial data read-outs are anticipated from 2025. Matt Barnes, President of Heptares Therapeutics and Head of UK R&D, said: “It’s great to see the progression of HTL’744, another of our wholly owned assets, into the clinic. EP4 agonists are a recognized and exciting class of drugs with a dual mechanism of action that can resolve inflammation and promote mucosal healing. We’ve utilized our StaR®/SBDD platform to develop a potent, selective and gut-restricted molecule that has potential to change the lives of the millions of people with IBD worldwide who are not benefitting from the currently available treatments.” -ENDS- About Sosei HeptaresSosei Heptares is a fully integrated, technology enabled pharmaceutical company focused on bringing life-changing medicines based on world-class science to patients globally. Our vision is to become one of Japan’s global pharmaceutical champions.  Our global business combines our world-leading GPCR-targeted StaR® technology, structure-based drug design and early development capabilities in the UK with a highly experienced clinical development capability and a commercial operation in Japan. We are leveraging these capabilities to generate and advance a broad and deep pipeline of novel medicines across multiple therapeutic areas, including neurology, immunology, gastroenterology and inflammatory diseases. We intend to develop these opportunities for patients in Japan and globally both internally and through our partnerships with global biopharmaceutical companies and emerging technology companies. Sosei Heptares operates from key locations in Tokyo and Osaka (Japan), London and Cambridge (UK), Basel (Switzerland) and Seoul (South Korea). “Sosei Heptares” is the corporate brand and trademark of Sosei Group Corporation, which is listed on the Tokyo Stock Exchange (ticker: 4565). Sosei, Heptares, the logo and StaR® are trademarks of Sosei Group companies. For more information, please visit https://soseiheptares.com/LinkedIn: @soseiheptaresco | X: @soseiheptaresco | YouTube: @soseiheptaresco Enquiries: Sosei Heptares – Media and Investor RelationsKentaro Tahara, VP Investor Relations and Corporate Strategy Shinichiro Nishishita, VP Investor Relations, Head of Regulatory DisclosuresMaya Bennison, Communications Manager+81 (0)3 5210 3399 | +44 (0)1223 949390 | [email protected] MEDiSTRAVA Consulting (for International Media)Mark Swallow, Frazer Hall, Erica Hollingsworth+44 (0)203 928 6900 | [email protected] Forward-looking statementsThis press release contains forward-looking statements, including statements about the discovery, development, and commercialization of products. Various risks may cause Sosei Group Corporation’s actual results to differ materially from those expressed or implied by the forward-looking statements, including: adverse results in clinical development programs; failure to obtain patent protection for inventions; commercial limitations imposed by patents owned or controlled by third parties; dependence upon strategic alliance partners to develop and commercialize products and services; difficulties or delays in obtaining regulatory approvals to market products and services resulting from development efforts; the requirement for substantial funding to conduct research and development and to expand commercialization activities; and product initiatives by competitors. As a result of these factors, prospective investors are cautioned not to rely on any forward-looking statements. We disclaim any intention or obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise. 1 Neurath, MF: Gut 61.11 (2012): S. 1619-1635. http://gut.bmj.com/content/61/11/1619 2 Rath T et al: Gastroenterology Volume 164, Issue 2, February 2023, Pages 241-255 https://doi.org/10.1053/j.gastro.2022.10.014