The European Commission over the weekend signed off on the first biosimilar for Amgen’s blockbuster rheumatoid arthritis treatment Enbrel, a version of which is also making its way through a separate review by the US Food and Drug Administration (FDA).

With almost $5 billion in annual sales last year (and almost $9 billion in 2014 sales), the biosimilar version of the treatment from Samsung Bioepis, known commercially as Benepali (etanercept), could help to drive down prescription drug costs in the EU.

“In just under four years, we successfully developed, tested and obtained regulatory approval for Benepali,” Christopher Hansung Ko, president & CEO of Samsung Bioepis, said, noting the biosimilar will not only drive down costs but increase patient access to one of the most widely used treatment options for immunological diseases in Europe.

The final approval by the commission comes two months after the European Medicines Agency’s Committee for Medicinal Products  for Human Use (CHMP) signed off on the biosimilar, and four months after South Korea’s Ministry of Food and Drug Safety (MFDS) cleared the anti-TNF treatment, which is marketed there as Brenzys.

US Battle Shaping Up

Samsung Bioepis said it is also planning to seek regulatory approval for the Enbrel biosimilar in the US (the patent was supposed to expire in 2012), where the company will face competition from Novartis, which in October became the first company to have its application accepted for review by FDA. Baxalta and Coherus Biosciences also said last week that their Enbrel biosimilar succeeded in a late-stage study.

But that competition for Enbrel will have to first deal with a patent fight between the competitor companies and Amgen, which in 2011 claimed to that it was granted a patent for the basic composition of Enbrel that would extend the exclusivity of the drug in the US to 2028.

Novartis’ subsidiary Sandoz has already tried to contest this patent in court, but that action was thrown out because the company had yet to file its biosimilar application with FDA.

According to the Generics and Biosimilars Initiative, at least 11 other companies are also developing biosimilar versions of Enbrel, including Cipla’s Etacept, which launched its product in India in 2013.