Biosion receives over $40 million cash payment as upfront license fee and reimbursement for certain development costs & drug product materials,and 19.9% shares of common stock of Aclaris Therapeutics; additional regulatory and sales milestone payments exceed $900M with tiered single digit sales royalty

Aclaris Therapeutics will be responsible for development and commercialization of BSI-045B,a novel anti-TSLP monoclonal antibody,and BSI-502,a novel bispecific antibody that is directed against both TSLP and IL4R worldwide (excluding Greater China)

NEWARK,Del. and NANJING,China,Nov. 18,2024 -- Biosion,Inc. (Biosion),a global R&D stage biotechnology company,today announced that it has entered into an exclusive license agreement with Aclaris Therapeutics (NASDAQ: ACRS) for worldwide rights (excluding Greater China) to BSI-045B,a potential First-in-class,clinical-stage,novel anti-TSLP monoclonal antibody,a potential best-in-class,pre-clinical stage,novel bispecific antibody that is directed against both TSLP and IL4R.

Under the terms of the agreement,Biosion shall receive over $40 million cash payment as upfront license fee and reimbursement for certain development costs & drug product materials. Biosion shall also receive 19.9% shares of common stock of Aclaris Therapeutics. Additional regulatory and sales milestone payments exceed $900M with tiered low-to-mid single digit royalty based upon a percentage of annual net sales.

"This transaction once again validates our proprietary antibody discovery platforms,BSI-045B and BSI-502 demonstrate the power of our discovery capabilities in generating potential first-in-class and best-in-class therapeutics."said Mingjiu Chen,Ph.D.,Founder and CEO of Biosion. "Together with our global partners through the complementary expertise and resources,we hope to bring more transformative medicines to patients worldwide."

"This transaction marks Biosion's ninth and tenth global partnered programs under our 'discover-development-partnership'model,"said Anthony Yeh,Chief Strategy Officer of Biosion. "This partnership accelerates the worldwide clinical development of two key assets while securing the financial resources necessary to advance our other innovative programs to IND filings."

In a completed Phase 2a,single-arm,proof-of-concept trial in the United States in 22 patients with moderate to severe atopic dermatitis,BSI-045B was observed to have a pharmacodynamic,safety and efficacy profile that could position it as a potential best-in-class therapy. BSI-045B is also being advanced in multiple Phase 2 studies in China by Biosion's regional partner,Chia Tai Tianqing Pharmaceutical Group,Co.,Ltd. (CTTQ),targeting both severe asthma and chronic rhinosinusitis with nasal polyps,accelerating the potential to show proof-of-concept across additional indications.

"This strategic transaction brings together Biosion's innovative programs with our development capabilities in immunology,and we are excited to enhance our portfolio with these compelling assets," said Dr. Neal Walker,Interim CEO and Chair of the Board of Directors of Aclaris. "We look forward to further developing these assets in our quest to deliver exceptional therapies for patients worldwide."

About BSI-045B

BSI-045B is a humanized anti-thymic stromal lymphopoietin (TSLP) monoclonal antibody that specifically binds to human TSLP,blocking its interaction with the receptor complex and disrupting signal transduction. This mechanism prevents immune cells targeted by TSLP from releasing proinflammatory cytokines. BSI-045B is currently in clinical development,and its safety and efficacy have not been evaluated by regulatory authorities.

About BSI-502

BSI-502 is a humanized anti-TSLP and anti-interleukin 4 receptor (IL4R) bispecific antibody that blocks both the upstream TSLP receptor signal transduction and downstream IL4R activation thereby inhibiting this central proinflammatory pathway. BSI-502 is currently in pre-clinical development,and its safety and efficacy have not been evaluated by regulatory authorities.

About Biosion

Biosion is a global clinical-stage biotechnology company focused on developing innovative antibody-based therapies to improve outcomes for patients with immune and oncologic diseases. Leveraging its proprietary technologies such as the H³antibody discovery platform,SynTracer® HT endocytosis platform,and Flexibody® bispecific platform,Biosion creates highly differentiated medicines to address significant unmet medical needs worldwide. With its "discover-development-partnership"model,the company has forged 10 global collaborations,advancing seven clinical-stage assets,including monoclonal antibodies,bispecific antibodies,and antibody-drug conjugates. Biosion operates across the US,and Australia. Learn more at www.Biosion.com.