Once-Daily Oral COVID-19 Antiviral Shows Rapid Virus Clearance

Japan-based Shionogi & Co., Ltd. announced new results from two late-breaking presentations of S-217622's Phase 2/3 clinical trial at the 32nd European Congress of Clinical Microbiology & Infectious Diseases.

On April 23, 2022, the company stated S-217622 is an investigational 3CL protease inhibitor studied for once-daily oral administration in mainly vaccinated patients, with no risk factors for severe complications, within five days of COVID-19 symptom onset.

These new data showed an antiviral effect:

• S-217622 demonstrated rapid clearance of the infectious SARS-CoV-2 virus.
• On day four of treatment (following the third dose), the proportion of patients with positive viral titer decreased by approximately 90% versus placebo.
• S-217622 shortened infectious virus shedding by 1-2 days versus placebo.
• S-217622 showed a significant reduction in viral RNA on days 2, 4, 6, and 9 versus placebo (difference versus placebo in the Least Squares mean change from baseline in viral RNA; under -1.0 logx copies/mL on day four at each dose).

“These results demonstrate that S-217622 rapidly eliminates SARS-CoV-2 in patients versus placebo, marking its potential, if approved, as an effective treatment option for COVID-19,” said Isao Teshirogi, Ph.D., President and CEO at Shionogi, in a related press release.

A separate global Phase 3 study of S-217622 is underway, aiming to recruit participants globally to support regulatory filings in 2022.

The full abstracts and oral presentations are available on the ECCMID website.

S-217622 was the first oral non-covalent, non-peptidic SARS-CoV-2 3CL protease inhibitor candidate to enter clinical study.

Additional COVID-19 antiviral treatment news is posted at PrecisionVaccinations.com/antivirals.

Note: This information was edited for clarity and manually curated for mobile readership.