Sosei Heptares Notes that its Partnered Adenosine A2a Antagonist Imaradenant (AZD4635) has been Removed from AstraZeneca's Clinical Pipeline

TOKYO and CAMBRIDGE, England, Nov. 12, 2021 /PRNewswire/ -- Sosei Group Corporation ("the Company") (TSE: 4565) notes that in AstraZeneca's third quarter 2021 clinical trials appendix presentation (published today and available on www.astrazeneca.com), the oral, small molecule adenosine A2a receptor antagonist imaradenant (AZD4635) has been removed from its clinical development pipeline as part of its ongoing pipeline prioritization. Imaradenant was discovered by Sosei Heptares and licensed to AstraZeneca in 2015.

AstraZeneca has been evaluating imaradenant in Phase 1 and 2 clinical trials as a monotherapy and in combination with Imfinzi (durvalumab) in solid tumors. In these trials, imaradenant, with or without Imfinzi, was found to be safe and well tolerated and associated with clinical benefit in some immune checkpoint-naïve patients with metastatic castrate-resistant prostate cancer (mCRPC). Imaradenant has been extensively tested in patients with a range of different solid tumor types and has been demonstrated to be safe and well tolerated at escalating doses.

Targeting the production or action of adenosine is a promising strategy for overcoming immune suppression in the tumor microenvironment, and several companies have now disclosed positive results from early clinical trials.

AstraZeneca has a diverse oncology pipeline that requires it to regularly make strategic prioritization decisions regarding projects in its portfolio. Following the removal of the imaradenant program from AstraZeneca's clinical pipeline, Sosei Heptares will discuss with its partner AstraZeneca the next steps for the future of imaradenant, including the possibility of the Company regaining worldwide rights to the licensed program.

The event reported today has no material impact on the consolidated financial results for the fourth quarter and full year accounting period ending 31 December 2021. Should any impacts or other matters that require an announcement be identified, the Company will announce such matters promptly.

Shinichi Tamura, President and CEO of Sosei Heptares, commented: "The imaradenant clinical program has generated encouraging clinical results in cancer patients under AstraZeneca's guidance. We respect their decision on imaradenant, as a result of a pipeline portfolio review, and we are keen to assess the possibility of regaining the worldwide rights in order to evaluate the future clinical development and/or re-licensing potential of the program, as we have successfully done so on multiple occasions. AstraZeneca is one of our longest serving partners, and we have enjoyed a highly productive collaboration with them. We look forward to the ongoing discussions about the future of imaradenant and will report the outcome in due course."

About Sosei Heptares

We are an international biopharmaceutical group focused on the discovery and early development of new medicines originating from our proprietary GPCR-targeted StaR® technology and structure-based drug design platform capabilities. We are advancing a broad and deep pipeline of novel medicines across multiple therapeutic areas, including neurology, immunology, gastroenterology and inflammatory diseases.

We have established partnerships with some of the world's leading pharmaceutical companies and multiple emerging technology companies, including AbbVie, AstraZeneca, Biohaven, Genentech (Roche), GSK, Novartis, Pfizer and Takeda. Sosei Heptares is headquartered in Tokyo, Japan with corporate and R&D facilities in Cambridge, UK.

"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/
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Enquiries:
Sosei Heptares – Media and Investor Relations
Hironoshin Nomura, SVP Investor Relations and Corporate Strategy
+81 (0)3 6679 2178
Hironoshin.Nomura@SoseiHeptares.com

Shinichiro Nishishita, VP Investor Relations, Head of Regulatory Disclosures
+81 (0)3 5210 3399
IR@SoseiHeptares.com

Citigate Dewe Rogerson (for Japanese Media)
Yas Fukuda
+81 (0)3 4360 9234 
Yas.Fukuda@citigatedewerogerson.com

MEDiSTRAVA Consulting (for International Media)
Mark Swallow, David Dible, Eleanor Perkin
+44 (0)20 7638 9571
SoseiHeptares@medistrava.com

Forward-looking statements

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