Ascletis Announces Positive Interim Data from the Phase IIb Expansion Cohort of ASC22 (Envafolimab) for Chronic Hepatitis B Functional Cure

HANGZHOU and SHAOXING, China, Sept. 28, 2023 /PRNewswire/ — Ascletis Pharma Inc. (HKEX: 1672, “Ascletis”) today announces positive interim data from the Phase IIb expansion cohort (the “Expansion Cohort”) of subcutaneously administered PD-L1 antibody ASC22 (Envafolimab) for functional cure of chronic hepatitis B (CHB).

The Expansion Cohort is a randomized, single-blind, placebo-controlled and multi-center clinical trial ( NCT04465890) and planned to enroll approximately 50 CHB patients with baseline hepatitis B surface antigen (HBsAg) ≤100 IU/mL who would be treated with 1.0 mg/kg ASC22 or placebo (at a ratio of approximately 4:1) once every two weeks (Q2W) for 24-week treatment plus 24-week follow-up. All patients in both ASC22 and placebo cohorts received nucleot(s)ide analogues (NAs) as a background therapy. In the second quarter of 2023, Ascletis successfully completed the enrollment of 49 CHB patients, including 40 patients in ASC22 cohort and 9 patients in placebo cohort.

Interim analysis was conducted when approximately 50% of the enrolled patients completed 24-week treatment of ASC22 or placebo. The interim analysis included 25 patients who completed 24-week treatment (19 patients in ASC22 cohort and 6 patients in placebo cohort). Topline results indicated that in ASC22 cohort, 4 patients (4/19, 21.1%) achieved HBsAg loss at the end of 24-week treatment. In contrast, there were no patients (0/6, 0%) achieving HBsAg loss at the end of 24-week treatment in the placebo cohort. ASC22 was generally safe and well tolerated. Most of ASC22 drug related adverse effects were Grade 1 or 2.

CHB remains to be a significantly unmet medical need globally, with approximately 86 million people in China and 1.59 million people in the U.S. infected with hepatitis B virus (HBV)[1].

“While pursuing Phase IIb clinical study of ASC22 (Envafolimab) as monotherapy for CHB patients with baseline HBsAg≤100 IU/mL, we are also engaging global partners to discuss collaboration on combo therapies to achieve higher functional cure rates for HBV.” said Dr. Jinzi J. Wu, Founder, Chairman and CEO of Ascletis.

[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.

About Ascletis

Ascletis is an innovative R&D driven biotech listed on the Hong Kong Stock Exchange (1672.HK), covering the entire value chain from discovery and development to manufacturing and commercialization. Led by a management team with deep expertise and a proven track record, Ascletis focuses on three therapeutic areas with unmet medical needs from a global perspective: viral diseases, non-alcoholic steatohepatitis (NASH) and oncology. Through excellent execution, Ascletis rapidly advances its drug pipeline with an aim of leading in global competition. To date, Ascletis has multiple drug candidates in its R&D pipeline. The most advanced drug candidates include ASC22 (CHB functional cure), ASC40 (acne), ASC40 (recurrent glioblastoma), ASC40 (NASH), ASC41 (NASH) and ASC61 (advanced solid tumors).

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SOURCE Ascletis Pharma Inc.