Pardes Biosciences has initiated a Phase II clinical trial of its oral, direct-acting, antiviral drug candidate, PBI-0451, to treat symptomatic adult Covid-19 patients in the non-hospital setting. 

The randomised, double-blind trial will assess the safety, antiviral activity, and efficacy of PBI-0451 versus a placebo in such patients who are not at high progression risk to severe disease.  

It is expected to enrol 210 subjects at nearly 75 US sites. 

To be part of the trial, the Covid-19 patients should have had symptoms for five days or less.

In the trial, subjects will be given oral 350mg doses of PBI-0451 twice-a-day or a placebo for five days. 

The proportion of subjects with SARS-CoV-2 below detection levels in nasal swab samples on day three will be the primary goal of the trial.

Analysing safety and tolerability, hospitalisation, and mortality, as well as the duration to sustained clinical recovery through day 28 defined key symptoms of the disease will comprise the trial’s secondary objectives.

The company plans to report initial data from the trial in the first quarter of next year.

Pardes Biosciences CEO and chair Tom Wiggans said: “Initiation of our PBI-0451 Phase II study marks a significant step towards our goal of bringing a self-administered, oral, well-tolerated, and easy-to-use Covid-19 treatment option to a broad patient population due to a unique, favourable drug-drug interaction profile. 

“PBI-0451 has the potential to be a stand-alone SARS-CoV-2 protease inhibitor that can be easily prescribed and administered to alleviate the burden of Covid-19 to patients and healthcare systems.”

According to findings from a Phase I trial, single and multiple dosages of the antiviral drug were found to have favourable tolerability.

No treatment-emergent drug-related adverse events linked to PBI-0451 were reported.

In February this year, the company reported interim data from the Phase I trial of PBI-0451 in healthy adults.