South Korean biopharmaceutical firm Celltrion Inc. said Monday that its drug Remsima SC for the treatment of autoimmune diseases has begun sales in the country.

The subcutaneous (SC) version of Remsima, a biosimilar copy of Janssen Biotech Inc.'s Remicade, will hit the shelves domestically following approval a year earlier.

Remsima, administered through intravascular injections, is used in the treatment of a number of diseases, from rheumatoid arthritis to Crohn's disease, Celltrion said.

The SC version allows patients to conveniently inject it by themselves, unlike the intravenous formulation that requires patients to visit hospitals.

The company said it intends to improve its competitiveness in the local autoimmune disease therapeutic agent market with the existing Remsima and Remsima SC.

Celltrion has already won approval for the sale of Remsima SC in Europe and applied for patents in over 90 countries, including the United States. (Yonhap)