(This story corrects to show that Hadlima belongs to Samsung Bioepis not Merck & Co Inc, which is commercializing the drug in the United States)

(Reuters) – The U.S. Food and Drug Administration approved Samsung Bioepis Co Ltd’s biosimilar to AbbVie Inc’s blockbuster rheumatoid arthritis treatment Humira, the health agency said on Tuesday.

The drug, Hadlima, was developed by South Korea’s Samsung Bioepis and comes with a boxed warning, the FDA’s harshest. The agency flagged increased risk of serious infections, including tuberculosis and bacterial sepsis. (https://bit.ly/30QH1M3)

Merck & Co Inc will commercialize the treatment in the United States.

Humira also comes with a black box warning, according to the FDA.

In October, the FDA approved Novartis AG’s copy of Humira. Humira already faces competition from biosimilars in Europe.

Humira is the world’s best-selling prescription medicine and in the six years since AbbVie spun out from device maker Abbott Labs, the drug has remained by far its top-earner. It brought in revenue of $19.94 billion for AbbVie in 2018.

AbbVie in November lowered its forecast for overseas sales of Humira, citing stiff competition in Europe from drugmakers including Mylan NV and Biogen Inc.

(Reporting by Aakash Jagadeesh Babu in Bengaluru; Editing by Bernard Orr)