Ascletis Pharma has dosed the first cohort’s four healthy participants in a Phase I clinical trial of its oral therapy ASC11, along with 100mg ritonavir tablets, to treat Covid-19.

The multiple-dose escalation trial, designed to evaluate the 3-chymotrypsin like protease (3CLpro) inhibitor ASC11, is expected to enrol 72 healthy subjects.

Subject enrolment is scheduled for completion in the first quarter of this year.

The double-blind, randomised, and placebo-controlled trial includes 60 participants in the single-dose and multiple-dose escalation cohorts, and 12 in the food effect trial.

Among the 60 subjects, 32 will be randomised into four cohorts and given escalated multiple doses of ASC11, with or without ritonavir 100mg tablets or a matching placebo twice-a-day for 5.5 days.

The trial will assess ASC11’s tolerability, safety, and pharmacokinetics (PK), and 100mg ritonavir tablets in healthy subjects.

It will randomise the 12 subjects in the food effect trial to receive ASC11 and ritonavir tablets two times for evaluating the food effect of ASC11 on PK, along with the tablets.

Ascletis Pharma founder, chairman and CEO Dr Jinzi Wu said: “We are excited that our Covid-19 drug candidates, ASC10 (RdRp inhibitor) and ASC11 (3CLpro inhibitor), which are discovered and developed in-house and with global patents, both have entered into clinical development, which again marks a great recognition to our in-house research and design capabilities in viral diseases.

“As the Covid-19 pandemic causes persistent huge social and economic implications globally, Ascletis will accelerate our clinical development to fight against the pandemic in China and other countries.”

Ascletis has submitted international patent applications for the in-house discovered, oral small molecule drug candidate ASC11 and related compounds.

In December last year, the company reported positive topline data from the Phase I multiple ascending dose trial of ASC10 in healthy participants to potentially treat Covid-19.