Wednesday's launch follows similar moves a day earlier by Amgen and Novartis Sandoz unit. A fourth so-called biosimilar copy of Humira is expected soon from Mylan.

The primary European patent on Humira expired on Oct. 16, opening the door to cheaper near-identical copies for treating rheumatoid arthritis, Crohn's disease, ulcerative colitis and psoriasis.

Humira's worldwide sales were $18 billion last year, of which around $4 billion (£3 billion) came from Europe, and healthcare providers are hoping for significant savings with the arrival of cut-price rivals.

Samsung Bioepis is a joint venture between Samsung BioLogics and Biogen.

News of the launch comes amid a slide in Samsung BioLogics shares after a local media report that said the company faces disciplinary action due to alleged accounting violations.

(Reporting by Ben Hirschler; editing by Jason Neely)