Ascletis Announces U.S. IND Approval of ASC22 (Envafolimab), a Subcutaneously Administered PD-L1 Antibody for Functional Cure of Chronic Hepatitis B

Ascletis Pharma Inc. (HKEX: 1672) announces today the Investigational New Drug (IND) application approval by U.S. Food and Drug Administration (FDA) and initiation of global development of ASC22 (Envafolimab), a first-in-class, subcutaneously administered PD-L1 antibody for functional cure of chronic hepatitis B (CHB).

The recent research paper[1], titled "Prevalence of Chronic Hepatitis B Virus Infection in the United States" published in June 2020, showed an overall estimated prevalence for chronic hepatitis B virus (HBV) infection in the U.S. of 1.59 million patients (range 1.25–2.49 million). Both the World Health Organization (WHO) and U.S. Department of Health and Human Services (DHHS) have articulated formal hepatitis elimination plans.

[1] Lim J K, Nguyen M H, Kim W R, et al. Prevalence of Chronic Hepatitis B Virus Infection in the United States [J]. The American journal of gastroenterology 2020, 115(9): 1429-38.

ASC22 Phase IIb study (ClinicalTrials.gov Identifier: NCT04465890) is a randomized, single-blind, placebo-controlled, multi-center clinical trial in China which evaluates the efficacy and safety of 149 CHB patients for 24-week treatment of 1 mg/kg or 2.5 mg/kg ASC22 or matching placebo given once every two weeks (Q2W) in combination with NAs. Interim results, which were accepted for oral presentation in Late Breaking Session at The Liver Meeting® 2021 by the American Association for the Study of Liver Diseases (AASLD) showed that in patients with the baseline hepatitis B surface antigen (HBsAg) level ≤ 500 IU/mL, approximately 19% (3/16) of patients in the treatment group obtained HBsAg loss versus no subject achieved HBsAg loss in the placebo group and no rebound after the last dosing of ASC22, indicating HBV functional cure.

Phase IIa and IIb clinical studies of ASC22 for HBV functional cure were selected for inclusion in the "Best of The Liver Meeting's Summary" in 2021 by AASLD review committee. Such inclusion is a singular honor and indicates the high level with which the AASLD review committee regards Ascletis' research in CHB functional cure.

Ascletis announced it had obtained a global and exclusive license as of 8 November, 2021 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 CHB functional cure, i.e. HBsAg loss, through blocking PD-1/PD-L1 pathway.

 "ASC22 (Envafolimab) U.S. IND approval enables us to initiate U.S. and global clinical trials for CHB functional cure. Meanwhile, we are looking forward to collaborating with the industrial leaders in the field of functional cure of CHB." said Jinzi J. Wu, PhD, Founder, Chairman and CEO of Ascletis.

About Ascletis

Ascletis is an innovative R&D driven biotech listed on the Hong Kong, S.A.R., China Stock Exchange (1672.Hong Kong, S.A.R., China), a global platform covering the entire value chain from discovery and development to manufacturing and commercialization. Ascletis is committed to developing and commercializing innovative drugs in the areas of viral diseases, NASH/PBC, and cancer (oral cancer metabolic checkpoint and immune checkpoint inhibitors) to address unmet medical needs both in China and globally. Led by a management team with deep expertise and a proven track record, Ascletis targets those therapeutic areas with unmet medical needs from a global perspective, and efficiently advances the developments of pipelines with an aim of leading in global competition. To date, Ascletis has three marketed products and 20 robust R&D pipelines of drug candidates with global competitiveness, and is actively exploring new therapeutic areas.

1. Viral Diseases: (1) Hepatitis B Virus (functional cure): focus on breakthrough therapies for CHB functional cure with a subcutaneously-injected PD-L1 antibody – ASC22 and Pegasys® as cornerstone drugs. (2) COVID-19 pipeline: currently includes (i) ritonavir oral tablet (100 mg), an authorized product, (ii) ASC10, an oral RNA dependent RNA polymerase (RdRp) inhibitor and (iii) ASC11, an oral 3-chymotrypsin like protease (3CLpro) inhibitor. (3) HIV/AIDS: ASC22, an immune therapy to restore HIV-specific immune responses and eventually lead to a functional cure of HIV-infected patients. (4) Hepatitis C: successfully launched an all-oral regimen of combining ASCLEVIR® and GANOVO® (RDV/DNV regimen).

2. Non-alcoholic Steatohepatitis/Primary Biliary Cholangitis: Gannex, a wholly-owned company of Ascletis, is dedicated to the R&D and commercialization of new drugs in the field of NASH. Gannex has three clinical stage drug candidates against three different targets – FASN, THRβ and FXR, three fixed-dose combinations for NASH and one PBC program targeting FXR.

3. Cancer (oral cancer metabolic checkpoint and immune checkpoint inhibitors): a pipeline of oral inhibitors targeting FASN, which plays a key role in cancer lipid metabolism, and a pipeline of oral PD-L1 small molecule next generation immune checkpoint inhibitors.

4. Exploratory Indications: Acne: Following NASH and recurrent GBM, the third indication for ASC40 has been approved to enter Phase 2 clinical trial. 

Source: Ascletis Pharma Inc.