Ascletis Pharma has reported positive topline data from the Phase I multiple ascending dose (MAD) clinical trial of its prodrug, ASC10, in healthy participants to potentially treat Covid-19.

According to the trial findings, all doses of ASC10, including an 800mg twice a day dose, were found to be safe and well tolerated in subjects in China. 

The safety profiles of ASC10 and a placebo were also reported to be similar. 

The active drug ASC10-A’s exposure following twice-a-day dosing with 800mg of double prodrug ASC10 in Chinese participants was 94% of that following twice-a-day dosing with 800mg of single prodrug molnupiravir in Japanese participants. 

In Chinese participants, on administering an 800mg dose, the plasma concentrations of the double prodrug ASC10 were found to be less than the detection limit.

Food had no impact on the exposure of ASC10-A, signifying that ASC10 could be administered with or without food.

Following the data from the Phase I trial of ASC10 and molnupiravir’s clinical efficacy findings in American, Japanese, and Chinese subjects, a twice a day 800mg dose of ASC10 was chosen for a registrational trial.

The oral tablet formulation of the ASC10 prodrug needed for the trial was developed using Ascletis’ technology.

The active drug ASC10-A is said to have potent antiviral activity against several Omicron variants such as BA.5 and BA.2.75. 

At present, the single prodrug, molnupiravir, is approved or authorised for usage in several regions including the US and Japan. 

Ascletis founder, chairman and CEO Dr Jinzi Wu said: “The Phase I clinical data have confirmed the druggability of ASC10 for Covid-19. 

“With the global patent filings, we expect that ASC10 will make contributions to fighting against the Covid-19 pandemic inside and outside China.”

The latest development comes after the China National Medical Products Administration (NMPA) granted clearance for the company’s Investigational New Drug (IND) application for the Phase I trial of ASC11 for Covid-19.