South Korea’s Samsung Bioepis said Monday that its biosimilar referencing Roche’s Herceptin has been approved for sale in Europe, marking the first cheaper copy of the blockbuster breast cancer therapy to win regulatory approval in the region.

The European Commission granted marketing approval for Ontruzant, Samsung’s Herceptin biosimilar, for the treatment of early breast cancer, metastatic breast cancer and metastatic gastric cancer.

With the approval, Ontruzant can now be sold in all of the 28 European Union member states as well as Norway, Iceland and Liechtenstein, the firm said.

MSD, also known as Merck & Co. in the US and Canada, will handle the drug’s commercialization as Samsung Bioepis’ marketing partner. Once it arrives in the market, Ontruzant is expected to eat into the sales of Herceptin, which generated around $6.8 billion in global revenue for Roche in 2016.

“Breast cancer remains the most common form of cancer affecting women. We hope Ontruzant will play an important role expanding patient access to trastuzumab across the region,” said Samsung Bioepis CEO and President Ko Han-sung in a statement.

Ontruzant is the fourth biosimilar developed by Samsung Bioepis to obtain the EC’s approval and the first cancer-targeting drug to score regulatory approval.

The Korean drugmaker has already obtained approval for three additional biosimilar drugs in Europe, each referencing Remicade, Enbrel and Humira. They are all anti-TNF therapies targeting autoimmune diseases such as rheumatoid arthritis and Crohn’s disease.

Though Samsung is the only biosimilar challenger in the Herceptin market in Europe for now, it is closely being followed by competitors. Korea’s Celltrion, Mylan and Biocon as well as Amgen and Allergan have submitted their own Herceptin biosimilars to European drug regulators.

News of Samsung Bioepis’ Herceptin biosimilar approval in Europe also lifted the share price of its parent company Samsung BioLogics on Monday. Shares of Samsung BioLogics hit an all-time high of 414,000 won ($378) during early morning trading.

Samsung Bioepis was founded in 2012 as a joint venture between contract drug manufacturer Samsung BioLogics and US drugmaker Biogen. Biogen holds a 5.4 percent stake in Bioepis, while Samsung BioLogics owns the remainder of the shares.

By Sohn Ji-young (jys@heraldcorp.com)