* Co's Herceptin copy already approved in Europe
* Herceptin is one of the world's best selling drugs (Adds background, Herceptin sales, changes slug)
SEOUL, Dec 20 (Reuters) - South Korea's Samsung Bioepis Co Ltd said on Wednesday the U.S. Food and Drug Administration (FDA) has accepted for review its copy of Swiss drugmaker Roche's blockbuster breast cancer drug Herceptin for potential approval.
Samsung Bioepis said in a statement that if approved, its version of Herceptin will be commercialised in the United States by Merck, known as MSD outside of the United States and Canada.
Samsung Bioepis' Herceptin copy, called Ontruzant, was the first biosimilar version of the drug to be approved in Europe.
Mylan NV's Herceptin biosimilar was the first biosimilar approved in the United States to treat breast or stomach cancer.
Herceptin is one of the world's most successful antibody drugs, generating global sales of 6.78 billion Swiss francs ($6.7 billion) in 2016 for Roche. (Reporting by Joyce Lee; Editing by Stephen Coates)