US biosimilar space reaches its Inflectra point

The entry of Inflectra, the biosimilar of Johnson & Johnson’s antirheumatic antibody Remicade, is probably not the chief thing its licensee Pfizer is concerned with today. Still, it is another milestone on the journey of generic biologicals to market.

Inflectra is the second biosimilar to reach the US after Novartis’s Zarxio last year, though Inflectra is the first copycat antibody. What will really shake things up will be the likely third market entrant: Amgen’s biosimilar form of the world’s bestselling drug, Humira, is under consideration by the FDA (see table below).

Inflectra, already sold in Europe by its originator, Celltrion, as Remsima, has been approved by the FDA for the same indications as Remicade with the exception of ulcerative colitis in paediatric patients. Pfizer gained US rights to Inflectra last year when it bought Hospira, which six years earlier had agreed to develop the biosimilar with Celltrion.

More to come

The main question facing biosimilars is whether doctors will view them as interchangeable with the branded antibody.

The FDA made it plain that Inflectra has not been approved as interchangeable – that is, a product that can be substituted for Remicade at a pharmacy – but the drug’s label states that it is “biosimilar to Remicade (infliximab) for the indications listed” and presents Remicade’s immunogenicity data as applying equally to Inflectra.

This indicates that the FDA will be welcoming to future biosimilars. Zarxio is a relatively simple protein, its approval was supported by near-perfect data and it had been in use for many years in Europe. None of this is true of Inflectra, yet it was still approved with strong hints that it could be used in place of the branded drug.

Analysts at Barclays cite a survey conducted by the European Crohn’s and Colitis Organisation, released last month, as showing that 44% of doctors would consider a Remicade biosimilar interchangeable with the original product, compared with only 6% in a 2013 survey. 92% of physicians felt that that cost saving was the primary advantage of using biosimilars, and the top concern with them was immunogenicity, reported by 69% of respondents.

Still, with Celltrion’s chief executive, Kim Hyoung-ki, suggesting yesterday that Inflectra could be priced 20-30% below Remicade in the US, in this case payers might well push for biosimilar use.

That is, if it makes it past the final barrier: IP. Remicade’s main patent is due to expire in September 2018 but is under review and could be swept aside. There is a legal battle over at least one other patent, though, and Bernstein analysts suggest that Pfizer and J&J are probably already in negotiations over Inflectra’s possible launch date; they suggest that it might not reach the US market until late 2017.

… Or maybe not

The Remicade IP wrangling looks like a picnic compared with that over Humira. The FDA accepted Amgen’s filing for its biosimilar version, ABP 501, in January, but the FDA is not the main gatekeeper. It is AbbVie that Amgen will have to face down to get ’501 to the US.

Humira’s composition of matter patent expires at the end of 2016, but it has other patents that last until 2034 (Amgen invites AbbVie to dance for Humira biosimilar, November 26, 2015). AbbVie’s management has promised to fight every legal battle it can to keep biosimilar competition from encroaching on Humira’s sales, which are forecast to peak at $18.2bn worldwide in 2018.

The biosimilars specialist Coherus BioSciences also has a Humira copycat in the works. It seems reasonable to assume that this will reach market only if Amgen’s ’501 gets there first.

There is a second infliximab biosimilar in the US pipeline as well, and intriguingly it belongs to Pfizer; unlike Inflectra it was developed in-house. The company sold European rights to PF-06438179 to Novartis’s Sandoz generics division but retains US rights; there seems little point in seeking FDA approval for the asset now Inflectra is approved.

And Pfizer has several other horses in the US biosimilar race. Retacrit, a version of Amgen’s Epogen, is filed with the FDA, while copies of the oncology antibodies Rituxan and Herceptin are in phase III.

Pfizer is shaping up to be a major force in biosimilars, at least in the US. But with makers of the original drugs fighting copycat entry every inch of the way the real winner in this sector might be the law firms.

To contact the writer of this story email Elizabeth Cairns in London at [email protected] or follow @LizEPVantage on Twitter