Professor Jonathan Kay (Division of Rheumatology, Department of Medicine, University of Massachusetts Medical School and UMass Memorial Medical Center, Worcester, Massachusetts, USA) tells Editor-in-Chief of RMD Open Bernard Combe why he supports the switch from branded drugs to their cheaper biosimilar.

They spoke at the EULAR conference 2017, held in Madrid, in June.

For more information on this topic read:

• Key design considerations on comparative clinical efficacy studies for biosimilars: adalimumab as an example - http://rmdopen.bmj.com/content/2/1/e000154

• Biosimilars: what do patients need to consider? - http://rmdopen.bmj.com/content/1/1/e000141

• Biosimilars in rheumatology: what the clinician should know - http://rmdopen.bmj.com/content/1/1/e000010