• Payment follows dosing of the first patient in a Phase 3 trial of APP13007 for the treatment of inflammation and pain after cataract surgery
• APP13007 originated at Activus Pharma, a former subsidiary of Sosei Heptares now owned by Formosa
• Sosei Heptares remains eligible to receive undisclosed milestone payments and royalties based on the progression of Activus’ pipeline at Formosa

Tokyo, Japan and Cambridge, UK, 11 March 2021 – Sosei Group Corporation (“the Company”; TSE: 4565) announces that Formosa Pharmaceuticals, Inc. (“Formosa”) has dosed the first patient in a 370-patient randomized Phase 3 clinical trial of APP13007 in the United States (ClinicalTrials.gov Identifier: NCT04739709). APP13007 is a nanoparticle formulation of a steroid in development for the treatment of inflammation and pain after cataract surgery. The milestone has triggered a US$2.5 million payment to Sosei Heptares from Formosa.

APP13007 was originally designed and developed at Activus Pharma Inc. (“Activus”), formerly a wholly owned subsidiary of the Company. Activus was divested in August 2017 to Formosa, a wholly owned subsidiary of Formosa Laboratories, Inc., a leading manufacturer of Active Pharmaceutical Ingredients (“APIs”) listed on the Taiwan Stock Exchange. The divestment was part of Sosei Heptares’ redirected growth strategy towards the design and development of new medicines originating from its proprietary GPCR-targeted StaR® technology and structure-based drug design platform capabilities.

Activus was originally developing APP13007 by applying its patented proprietary APNT (“Activus Pure Nanoparticle Technology”) to the steroid to create a novel nanoparticle formulation for treating post-operative inflammation of the eye. Since the divestment, Formosa has progressed the development of APP13007 and is now aiming to begin Phase 3 trials in the United States imminently.

Under the terms of the sale to Formosa in 2017, Sosei Heptares is entitled to receive undisclosed milestone payments based on progression of Activus’ pipeline as well as royalties from the commercialization of certain products should they reach the market.

Shinichi Tamura, Chairman, President and CEO of Sosei Heptares, said: “It is great to see the progress that Formosa has made advancing the development of APP13007. Entering Phase 3 trials is a fantastic achievement. We wish the Formosa team well in conducting this important trial and look forward to the results upon its completion.”

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