HANGZHOU, China and SHAOXING, China and SUZHOU, China, Nov. 7, 2021 /PRNewswire/ -- Ascletis Pharma Inc. (1672.HK) and Suzhou Alphamab Co., Ltd. (Suzhou Alphamab) jointly announce today that Ascletis' subsidiary and Suzhou Alphamab have entered into an exclusive and worldwide license agreement outside Greater China for ASC22 (Envafolimab) to treat all viral diseases including Hepatitis B. ASC22, also known as KN035, is a first-in-class subcutaneously injected PD-L1 antibody. Oncology indications are under development by Jiangsu Alphamab Biopharmaceuticals Co., Ltd. and an oncology biologic license application ("BLA") of KN035 was submitted to China National Medicine Products Administration (NMPA) in December 2020.

Under the terms of this agreement, Ascletis obtained an exclusive and worldwide license outside Greater China from Suzhou Alphamab to develop and commercialize ASC22 for all viral diseases including Hepatitis B. Ascletis will pay Suzhou Alphamab a cash upfront payment and Suzhou Alphamab will be eligible to receive payments from Ascletis on development, regulatory and commercial milestones as well as tiered royalties from the mid-teens to around twenty percent on future sales of ASC22. Suzhou Alphamab will manufacture ASC22 for clinical trials and commercialization of viral indications for Ascletis.

Together with the exclusive license agreement in Greater China announced jointly by Ascletis and Suzhou Alphamab on January 14, 2019 (Details referring to press release: https://www.ascletis.com/news_detail/171/id/290.html), Ascletis has now obtained a global and exclusive license from Suzhou Alphamab to develop and commercialize ASC22 for all viral diseases including Hepatitis B. Ascletis books sales globally for ASC22 of all viral diseases.

ASC22 is the most advanced clinical stage immunotherapy in the world for chronic hepatitis B (CHB) functional cure, i.e. hepatitis B surface antigen (HBsAg) loss, through blocking PD-1/PD-L1 pathway. A Phase IIa clinical trial of ASC22 in CHB patients was completed and the data indicated that there was a trend of dose dependent HBsAg reduction after single dose administration of 0.3, 1.0 or 2.5 mg/kg ASC22. Among three patients receiving 2.5 mg/kg dose, one patient achieved a maximum HBsAg reduction of 1.2 log₁₀ IU/mL during the 12-week follow up. The Phase IIa results will be presented in oral parallel session at The Liver Meeting^® 2021 by the American Association for the Study of Liver Diseases (AASLD), one of the world's premier meetings on liver disease and will be held during November 12 to November 15 this year. ASC22 is currently in a Phase IIb clinical trial in China with the entire enrollment of 149 CHB patients completed in July this year and preliminary Phase IIb data indicated that HBsAg reduction was observed in the 1 mg/kg ASC22 once every two weeks plus nucleos(t)ide analogs group with greater HBsAg reduction observed in patients with HBsAg ≤ 500 IU/mL at baseline while no HBsAg reduction was observed for the placebo plus nucleos(t)ide analogs group.

Jinzi J. Wu, PhD, Founder, Chairman and CEO at Ascletis said, "Suzhou Alphamab is a leading biopharmaceutical company and we're thrilled to partner with it on a global basis. Ascletis is a global leader in antiviral drug development such as Hepatitis B which remains a highly unmet medical need globally. Through the strategic partnership with Alphamab, we are accelerating the global development of ASC22 as a first-in-class HBV immunotherapy with the encouraging Phase IIa and Phase IIb efficacy data as well as the advantage in safety and convenience, and hope to offer a functional cure for Hepatitis B patients soon.