South Korean drugmaker Celltrion Inc on Monday announced positive results for its experimental antibody Covid-19 treatment that it said was safe and reduced the treatment period by nearly five days in Phase 3 global clinical trials.

The trials, which involved 1,315 participants, have taken place since January in 13 countries, including in South Korea, the United States, Spain and Romania, Celltrion said in a statement.

The treatment slowed severe symptoms of Covid-19 in more than 70% of patients, including the high-risk group with underlying conditions. It also cut the recovery period by 4.9 days, the company said.

In February South Korea, granted conditional approval to the antibody treatment, making it the first locally made coronavirus treatment in the country to win such approval. The company said it would seek full authorization based on the trial results.

Celltrion shares rose as much as 5.6% in Monday morning trade, compared with a 0.3% drop in the wider market.