Ascletis Pharma Inc. announced that the clinical study of PD-L1 antibody ASC22 (Envafolimab) in combination with Chidamide for functional cure of human immunodeficiency virus (HIV) infection has completed the enrollment of 15 HIV infected patients. The objective of this study (ClinicalTrials.gov Identifier: NCT05129189) is to evaluate the efficacy of ASC22 (Envafolimab) combined with Chidamide on the viral reservoirs of latently infected cells in HIV patients. Ascletis BioScience Co.

Ltd. and Shenzhen Chipscreen Biosciences Co. Ltd. provide ASC22 (Envafolimab) and Chidamide, respectively, for the clinical trial. The study design of this trial is 1 mg/kg ASC22 (Envafolimab) subcutaneous injection once every four weeks (Q4W) in combination with 10 mg Chidamide administered orally twice a week (BIW) with 12-week treatment.

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 such as hepatitis B virus (HBV) and HIV. Latently infected cells by HIV are a major barrier to curing HIV infection. Recent data demonstrated that blocking PD-1/PD-L1 pathway resulted in reversing HIV latency in the clinical trial and supported the rationale for combining PD-1/PD-L1 antibody with other drugs to reduce the HIV reservoir of latently infected cells.

Chidamide is the global first approved subtype-selective histone deacetylase oral inhibitor (HDACi) mainly targeting the subtype 1, 2, 3 of Class I and subtype 10 of Class IIb histone deacetylase (HDAC), with a mechanism against epigenetic abnormality.