GENEVA, Switzerland - Swiss pharmaceutical giant Roche said Tuesday that Japan had become the first country to fully approve its Ronapreve antibody treatment for patients with mild to moderate COVID-19.

The approval was based on phase 3 trials finding that the antibody cocktail dramatically reduced the likelihood that mild or moderate COVID-19 patients would develop into serious illness causing hospitalization or death.

Ronapreve, developed in cooperation with US biotech firm Regeneron, was approved by Japan's ministry of health, labor and welfare, Roche said in a statement, confirming it was the "first country" to do so.

"Ronapreve has been shown to improve survival in high-risk, non-hospitalised COVID-19 patients by reducing the risk of hospitalisation and death," Roche chief medical officer and product development chief Levi Garraway said in a statement.

"Its ability to retain activity against emerging variants, including the Delta variant, has been demonstrated in preclinical studies," he said.

Roche said the phase 3 trials of Ronapreve had shown that high-risk non-hospitalized patients treated with the drug had a 70 percent reduction in subsequent hospitalization and death.

It also shorted the period of symptomatic illness by four days, Roche said, adding that the phase 1 trials had showed the safety and tolerability of the drug among the Japanese population.

Outside Japan, the antibody combination has been authorized for emergency or temporary pandemic use in a number of countries and regions, including the European Union, United States, India, Switzerland and Canada, Roche said.

The blend is currently undergoing a rolling review by the European Medicines Agency, which has granted its use as a treatment option for COVID-19 patients who do not require oxygen, but who are at high risk of developing severe disease.