Ascletis Pharma has dosed the first participant in the clinical trial of ASC22 (envafolimab) plus chidamide for functional cure of human immunodeficiency virus (HIV) infection.

ASC22 is a single domain antibody against programmed death-ligand 1 (PD-L1).

It is given subcutaneously and can restore virus-specific immune responses in chronic viral infection patients.

Last month, the company dosed the first participant in the Phase II clinical trial of ASC22 along with anti-retroviral therapy (ART) for immune restoration/ functional cure of HIV-1 infection in China.

The investigator-initiated trial was designed to assess ASC22’s safety and efficacy to treat HIV-1 infection versus placebo, along with ART once every four weeks (Q4W) during 12-week treatment and 12-week follow-up.

Initiated by Shanghai Public Health Clinical Center , the study will further explore the PD-L1 antibody’s potential in combination with Chidamide.

Chidamide mainly targets the subtype 1, 2, 3 of Class I and subtype 10 of Class IIb histone deacetylase (HDAC) and acts against epigenetic abnormality.

It is said to be the first approved subtype-selective histone deacetylase oral inhibitor (HDACi) in the world.

As per the recent data, blocking the PD-1/PD-L1 pathway reversed HIV latency and supported the rationale for combining PD-1/PD-L1 antibody with other drugs for reducing the HIV reservoir of latently infected cells.

Ascletis Pharma chairman, founder, and CEO Dr Jinzi Wu said: “The completion of the first patient dosing marks a new milestone of the study of PD-L1 antibody ASC22 in combination with Chidamide for functional cure of HIV infection.

“Functional cure of HIV/AIDS remains a challenge in China and globally despite the improved access of standard ART treatment.

“PD-1 and PD-L1 expressions are elevated in HIV-1 infected patients compared to healthy subjects.”

The company stated that the clinical trials on ASC22 in combination and as monotherapy are conducive to improve its pipeline on HIV functional cure.