An experimental COVID-19 drug cut the risk of death among severely ill patients by more than half in a late-stage trial – an optimistic development that drove its manufacturer’s stock to fresh highs in trading this week.

The drug, sabizabulin, was so effective in treating COVID-19 cases among hospitalized patients in the phase three trial that independent safety monitors recommended the study be stopped early, according to biopharmaceutical firm Veru Inc.

Veru officials said the experimental treatment lowered the risk of death by 55% among hospitalized patients with moderate to severe cases of COVID-19 compared to those who received a placebo.

Independent monitors did not identify any safety concerns with the drug during the trial.

“This study represents a significant milestone in the global fight against COVID-19 as sabizabulin is the first drug to demonstrate a clinically and statistically meaningful reduction in deaths in hospitalized patients with moderate to severe COVID-19,” Veru CEO Mitchell Steiner said in a statement.

The promising results surfaced amid mounting fears of another COVID-19 wave in the US. Still, case levels remain low as the Omicron BA.2 subvariant spreads.

Veru Inc. shares were up 70% in trading this week, at one point touching a 52-week high of $14.57.

Veru’s findings have yet to be peer-reviewed. The company said it plans to meet with officials from the U.S. Food and Drug Administration to “discuss next steps including the submission of an emergency use authorization application.”

The FDA previously fast-tracked the sabizabulin drug for clinical testing in January.

Researchers have continued to develop treatments for COVID-19 patients to supplement vaccines developed by Pfizer, Moderna and other pharma firms.

Another treatment, the Pfizer-manufactured drug Paxlovid, gained an emergency use authorization from the FDA last December. Pfizer said its research showed the drug reduced the risk of hospitalization or death by 89% in high-risk adults – though the drug is intended for those who have yet to develop severe illness.