While lobbyists and state legislatures such as those in Colorado and Mississippi tussle over how much discretion doctors will have over biosimilars taking the place of branded biologics, a report by market intelligence firm GBI Research suggests industry watchers should not expect rheumatoid arthritis biosimilars to take the lead, even once state and Federal rules are in place.

Among the reasons analyst Dominic Trewartha cited in a statement: rheumatologists tend to be conservative in practice and are likely to be wary of switching things up in favor of a new treatment. Plus, Trewartha noted, there’s little incentive to change from a branded RA biologic to a biosimilar because “none of the potential market entrants appear to offer any significant improvements to existing medications . . . leaving Remicade, Humira and Enbrel to maintain their top-selling RA mABs status,” he said.

That would mean the $15.7-billion-dollar market GBI projects for the global RA space through 2018 will remain largely insulated from biosimilar competition for the time being.

On the industry side, GBI also noted that the RA biosimilars market is going to be small because of development costs, and that a small pool of competitors is “expected to limit the number of biosimilars and their impact on drug pricing for RA mAbs.”

Rheumatoid arthritis biologics are also a tough market to gain traction in because of the complexity of the biologic itself. In an earlier interview, Nathan Dowden, managing director of life sciences at the consultancy Frankel Group, told MM&M that gaining traction in the biosimilars market is about gaining trust. He said the RA market may be an easier entry point than cancer treatments, for example, but he said doctors are going to need time to trust an RA biosimilar because a monoclonal antibody ranks high in terms of complexity compared to simpler biologics like insulin. Former FDA associate commissioner Peter Pitts told MM&M that these less-complex brand twins will probably be the biosimilars physicians will gravitate towards first, because HCPs understand them best.