Sosei Heptares announces that a second novel drug candidate from its multi-target drug discovery collaboration with Pfizer has started clinical trials

- Dosing of first subject in clinical trial by Pfizer triggers $5 million payment to Sosei Heptares

- Clinical development candidate is an oral, small molecule modulator of an undisclosed G protein-coupled receptor (GPCR) target

- Eighth GPCR-targeted drug candidate to enter clinical development originating from Sosei Heptares' StaR technology/SBDD platform

TOKYO and CAMBRIDGE, England, Sept. 28, 2020 /PRNewswire/ -- Sosei Group Corporation ("the Company") (TSE: 4565) has been notified by Pfizer that the first subject in a clinical trial has been dosed with a new drug candidate nominated from the multi-target drug discovery collaboration between the two companies. Achievement of this milestone triggers a payment of $5 million to Sosei Heptares. This candidate was nominated for advancement by Pfizer in June 2019 generating a $3 million milestone payment at that time.

Pfizer nominated three distinct clinical candidates from the collaboration with Sosei Heptares during 2019, two of which have now subsequently entered clinical trials. The collaboration has leveraged Sosei Heptares' unique StaR technology and Structure-based Drug Design (SBDD) capabilities to design oral small molecules that modulate different G protein-coupled receptor (GPCR) targets across multiple disease areas of interest to Pfizer.

This candidate is the eighth GPCR-targeted drug candidate to enter clinical trials originating from Sosei Heptares' StaR technology and structure-based drug design (SBDD) platform.

Dr. Rob Cooke, Chief Technology Officer of Sosei Heptares, said: "The start of this new clinical trial is another great example of the productivity of our StaR technology and structure-based drug design approach. It also highlights our ability to work collaboratively and successfully with leading pharma companies, applying cutting-edge complementary capabilities to discover and develop completely new drug candidates with potential to treat major diseases. We are extremely pleased with the progress being made in our long-term partnership with Pfizer."

About the Agreement with Pfizer

Sosei Heptares and Pfizer entered a multi-target drug discovery collaboration in November 2015 to research and develop potential new medicines directed at up to ten GPCR targets across multiple therapeutic areas. Many of these targets have clinical or biological validation as key points for therapeutic intervention potentially targeting a range of diseases but have proven difficult to address with conventional discovery approaches because of inherent technical challenges.

To address these challenges, Sosei Heptares and Pfizer scientists worked closely together to leverage their respective complementary expertise in enabling GPCR-focused structure-based drug design (SBDD) and development initially directed to the GPCR targets selected by Pfizer. Pfizer is responsible for developing and commercializing any potential therapeutic agents (small molecules or biologics) for each target and will have exclusive global rights to any potential resulting agents.

Sosei Heptares has delivered multiple stabilized receptors (StaR proteins), X-ray structures and biophysical data on certain programs, triggering multiple significant milestone payments from Pfizer resulting from the nomination of new clinical candidates and entry into clinical trials. Further possible milestones payments are contemplated under the agreement, with potential for royalties also payable provided the criteria under the agreement are satisfied.

Pfizer also made a $33 million equity investment in Sosei Heptares in 2015. In the future, Pfizer and Sosei Heptares anticipate publication of select research findings from their collaboration.

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, including AbbVie, AstraZeneca, Genentech (Roche), Novartis, Pfizer and Takeda and additionally with multiple emerging technology companies. 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://www.soseiheptares.com/

LinkedIn: @soseiheptaresco | Twitter: @soseiheptaresco | YouTube: @soseiheptaresco

Forward-looking statements

This 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.

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