First HBV Patient Dosed in Phase IIa Clinical Trial of ASC22, a Subcutaneously Administered PD-L1 Antibody

HANGZHOU,Chinaand SHAOXING,China,Aug. 17,2020 -- Ascletis Pharma Inc. (HKEX code: 1672) announces today dosing of the first HBV patient in Phase IIa clinical trial of ASC22,which is a first-in-class,subcutaneously administered PD-L1 antibody.

ASC22(Envafolimab) Phase IIa clinical trial is a single dose escalation study with three subcutaneously administered doses (0.3,1.0 and 2.5 mg/kg) to explore the safety and efficacy of ASC22(Envafolimab) in chronic hepatitis B patients (ClinicalTrials.gov Identifier: NCT04465890).

As T cell exhaustion in chronic HBV infections is an important factor in immune tolerance,blocking the PD-1/PD-L1 pathway could be an effective immunotherapy approach to improve specific T cell function and lead to an effective clinical cure for chronic hepatitis B. There are 257 million people worldwide,including 70 million people in China,infected by HBV.

"We are excited about dosing the first chronic hepatitis B patient with ASC22(Envafolimab)," said Dr. Jinzi J. Wu,Founder,Chairman and CEO of Ascletis. "As a first-in-class immunotherapy with the potential to clinically cure chronic hepatitis B,ASC22(Envafolimab) offers convenient subcutaneous injections for patients and has potential to be a cornerstone therapy in various treatment regimens,includingcombinations with our in-house developed drug candidates and potentially with drug candidates from other industrial leaders."

"We are expecting the clinical results of the safety and efficacy of Envafolimab in HBV patients," said Dr. Ting Xu,Chairman of Alphamab. "Due to its unique immune mechanism,Envafolimab is likely to trigger HBV specific immune response,produce seroconversion,and bring hope of cure to patients. And it may also be used in patients with other chronic viral infections. The safety and convenience of subcutaneous administration of Envafolimab have been reflected to the greatest extent in the treatment of chronic diseases."

About ASC22

ASC22,also known as KN035 or Envafolimab,licensed from Alphamab by Ascletis for all viral indications,is a PD-L1 single domain antibody Fc fusion and has the advantages of subcutaneous injection and good stability at room temperature. These would be of great value to improve patients' compliance and quality of life and to help realize the goal of long-term management of chronic diseases such as chronic hepatitis B. Ascletis and Suzhou Alphamab Co.,Ltd. announced on January 14,2019 the strategic collaboration and licensing agreement for anti-PD-L1 to treat Hepatitis B and other viral diseases. Envafolimab has been enrolled in more than 1,000 patients and has shown good safety and efficacy in multiple tumor indications. Alphamab is preparing to submit a new drug application for MSI-H solid tumors.

About Alphamab

Suzhou Alphamab Co.,Ltd.,focused on research and development of mAbs,fusion proteins and other biological macromolecule drugs. With multiple proprietary platforms in antibody screening,protein engineering,CMC development and pilot production set up in its 6000m2 laboratory in bioBAY Suzhou,Alphamab has created a robust pipeline of over 50 promgrams,of which 20+ are innovative. Alphamab aims to develop affordable and efficient biological drugs to address high unmet medical needs globally.

About Ascletis

Ascletis is an innovative R&D driven biotech with three commercial products and listed on Hong Kong Stock Exchange (Ascletis,1672.HK). Ascletis is committed to developing and commercializing antiviral,steatohepatitis,and tumor-related innovative drugs for unmet medical needs in China and Globally. Led by a management team with deep expertise and a proven track record,Ascletis has developed into a fully integrated platform covering the entire value chain from discovery and development to manufacturing and commercialization. Ascletis' pipeline is focused primarily on three therapeutic areas: 1. HCV: two commercial stage products and two R&D stage drug candidates. Ganovo® (Danoprevir) is the first direct-acting anti-viral agent for hepatitis C,developed by a domestic firm in China. Asclevir® (Ravidasvir) in combination with Ganovo® (Danoprevir) (RDV/DNV Regimen) is the first all-oral HCV regimen developed by a domestic company in China. 2. HBV: one commercial stage product and three R&D stage drug candidates. Pegasys® (Peginterferon alfa-2a) is a leading marketed pegylated interferon for hepatitis B&C partnered with Roche. 3. NASH (Non-Alcoholic SteatoHepatitis): three R&D stage drug candidates against three different targets for combination treatments. For more information,please visit www.ascletis.com.