Ascletis Pharma has dosed the first subject in the Phase II clinical trial of ASC22 (Envafolimab) plus anti-retroviral therapy (ART) for immune restoration/ functional cure of human immunodeficiency virus 1 (HIV-1) infection in China.

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

It could potentially restore virus-specific immune responses in people with chronic viral infection. 

The randomised, placebo-controlled, single-blind, multicentre trial will analyse the safety and efficacy of ASC22 to treat HIV-1 infection versus placebo, along with ART during a 12-week treatment and 12-week follow-up period.

The company plans to conclude the trial earlier next year and will enrol nearly 30 subjects.

Participants in the ASC22 group will be given subcutaneous doses of 1mg/kg or 2.5mg/kg plus standard ART including integrase inhibitors (INSTIs) once every four weeks (Q4W) for 12 weeks. 

Subjects in the placebo arm will receive 0.9% saline plus ART Q4W for 12 weeks. 

The primary outcome measures of the trial are variation in CD4/CD8 ratio from baseline recorded at weeks 4, 8 and 12.

Ascletis Pharma founder, chairman and CEO Dr Jinzi Wu said: “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.”

Apart from the immune restoration/functional cure indication for HIV-1, the company developed another indication of ASC22 as a functional cure for chronic hepatitis B.

In April this year, Ascletis reported that its oral small molecule drug candidate, ASC11, demonstrated the potential to treat Covid-19.