New data for Shionogi’s COVID-19 antiviral show rapid virus clearance

Shionogi has announced new results from two late-breaking presentations of S-217622. This is an investigational 3CL protease inhibitor that was studied for once-daily oral administration in mainly vaccinated patients, with no risk factors for severe complications, within five days of COVID-19 symptoms onset.

The results were presented at the 32nd European Congress of Clinical Microbiology & Infectious Diseases (ECCMID) in Lisbon, 23-26 April.

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. The antiviral shortened infectious virus shedding by 1-2 days versus placebo, and also demonstrated a significant reduction in viral RNA on days 2, 4, 6 and 9, versus placebo.

There was no significant difference in the total score of 12 COVID-19 symptoms between treatment arms, but the antiviral showed improvement in the composite score of five “respiratory and feverish” symptoms.

“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. As infections continue to rise in areas worldwide, it is important we have access to a range of easily administered treatment options to ease the pressures on our healthcare systems,” said Isao Teshirogi, PhD, President and CEO at Shionogi & Co, Ltd. “We look forward to continued study of this antiviral in Phase III trials.”

A separate global Phase III study of S-217622 is now underway – aiming to recruit participants globally to support regulatory filings this year.

Lina Adams