Pfizer Inc's drug for multiple inflammatory diseases was approved in the United States, making it the second biosimilar to be approved by the U.S. Food and Drug Administration.

The drug Inflectra, a copy of Johnson & Johnson's Remicade, is approved for use in patients with diseases such as Crohn's disease, rheumatoid arthritis and ulcerative colitis, the FDA said on Tuesday.

Biosimilars are copies of biotech drugs and they are watched by investors for their potential to take business away from companies making the original, expensive product.

Inflectra is manufactured by Korean drugmaker Celltrion Inc for Hospira, a unit of Pfizer. (Reporting by Rosmi Shaji in Bengaluru; Editing by Don Sebastian)