Ascletis Announced First Subject Dosed in the Phase II Clinical Trial of ASC22 (Envafolimab) for Immune Restoration/ Functional Cure of HIV-1 Infection

-- The Phase II clinical study in China is currently expected to be completed in early 2023 with an expected enrollment of 30 subjects


Hangzhou and Shaoxing, China, June 28, 2022-- Ascletis Pharma Inc. (HKEX: 1672, “Ascletis”) today announces that the first subject has been dosed in the China Phase II clinical trial of ASC22 (Envafolimab) in combination with anti-retroviral therapy (ART) for immune restoration/ functional cure of human immunodeficiency virus 1 (HIV-1) infection.

ASC22 (Envafolimab) is a subcutaneously administered single domain antibody against PD-L1 and has the potential to restore virus-specific immune responses in patients with chronic viral infection. In addition to the indication of immune restoration/functional cure of HIV-1 infection, Ascletis has developed another indication of ASC22, that is, the one on functional cure of chronic hepatitis B.

This Phase II study ( Identifier: NCT05330143) is a randomized, single-blind, placebo-controlled, multi-center clinical trial in China to evaluate the safety and efficacy of ASC22 for treatment of HIV-1 infection at the dosage of 1 mg/kg or 2.5 mg/kg or placebo in combination with ART once every four weeks (Q4W) during 12-week treatment and 12-week follow-up.

Subjects of ASC22 arm will be subcutaneously administered with 1 mg/kg or 2.5 mg/kg plus standard ART including Integrase inhibitors (INSTIs) Q4W for 12 weeks. In placebo arm, subjects will be given 0.9% saline plus ART Q4W for 12 weeks. The changes of CD4/CD8 ratio from baseline will be recorded at Week 4, Week 8 and Week 12 as the primary outcome measures.

It was estimated that there were approximately 37.7 million people living with HIV globally with 0.68 million deaths and 1.5 million new infections in 2020[1]. Combination ART can suppress the virus in blood, but it is not curative, as nearly all HIV infected individuals will experience viral rebound within weeks or months when ART is discontinued.

“ART treatment can effectively suppress HIV replication, delay or even stop disease progression, but it cannot eliminate the HIV reservoir, which is the major hurdle in achieving a cure for HIV/AIDS. The Phase II trial of PD-L1 antibody ASC22 initiated by Ascletis aims at enhancing the immunity against virus to improve the potential of host immune surveillance to clear HIV reservoir. This study is conducive to further exploring the possibility of clearing HIV reservoir to achieve the functional cure of HIV/AIDS. We expect to generate more evidence to support this immune-based strategy and benefit more people.” said Prof. Fu-Sheng Wang, M.D., Ph.D., Academician of the Chinese Academy of Sciences, Director of Department of Infectious Diseases of Fifth Medical Centre of Chinese PLA General Hospital and the principal investigator of the ASC22 Phase II study.

“I’m very glad to know that the Phase II trial of ASC22 for immune restoration/ functional cure of HIV-1 infection has completed its first subject dosing with the great support from Prof. Linghua Li and her team at Guangzhou Eighth People’s Hospital, Guangzhou Medical University. It marks a new milestone that Ascletis has achieved in developing therapy for functional cure of HIV/AIDS, which is still a challenge in China and globally despite the improved access of standard ART treatment. By blocking PD-1/PD-L1 pathway, ASC22 is expected to potentially restore HIV-1 specific immunity and clear the latent HIV reservoir. We will accelerate the clinical study of ASC22 and share more milestones in the near future.” said Dr. Jinzi J. Wu, Founder, Chairman and CEO of Ascletis.


[1] UNAIDS. Global HIV & AIDS statistics — FACT SHEET. 2021.


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 three marketed products, i.e. ritonavir tablets, GANOVO® and ASCLEVIR®, and 20 drug candidates in its R&D pipeline. The most advanced drug candidates include ASC22 (CHB functional cure), ASC10 and ASC11 (oral small molecules for COVID-19 treatment), ASC40 (recurrent glioblastoma), ASC42 (PBC, primary biliary cholangitis), and ASC40 (acne).

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