SEOUL, Sept 17 (Reuters) - South Korea said on Thursday it has approved Celltrion Inc's experimental COVID-19 treatment for Phase 2/3 clinical trials, as the firm plans to seek a conditional approval of the antibody drug for an emergency use.

Celltrion has said it would begin commercial production of the drug, CT-P59, this month - likely to amount to around 1 million doses, in anticipation of demand in Korea and overseas.

The treatment, the most advanced antibody drug in terms of research in South Korea, is directed against the surface of the virus and designed to block it from locking on to human cells.

The Ministry of Food and Drug Safety said safety and efficacy of the drug were shown in the early stage of a trial, and a Phase 2/3 study will be offered to 1,020 participants.

Other companies developing potential COVID-19 treatments include Eli Lilly and Co, Regeneron Pharmaceuticals Inc and AbbVie.

Celltrion said human trials of the treatment will be carried out in 12 countries including Britain, Spain and the United States, and it anticipates primary results by the end of the year. (Reporting by Sangmi Cha; writing by Miyoung Kim; editing by Jason Neely)