Hospira and Celltrion hit a speed bump in their biosimilar dash

The FDA wants some more time to review Hospira ($HSP) and partner Celltrion's copy of Johnson & Johnson's ($JNJ) blockbuster autoimmune drug Remicade, possibly delaying the drug's march onto the U.S. market.

The agency is postponing a March 17 discussion of the biosimilar's merits, writing in a brief note on its website that the delay was "due to information requests pending with the sponsor of the application." It's unclear what that might specifically entail, and a Celltrion spokesman said only that the company is working to answer all of the agency's questions and expects the panel to convene "at a later date in 2015."

At the meeting, whenever it happens, a committee of independent advisors will discuss how well Celltrion and Hospira's take on Remicade stacks up to the original, voting whether to recommend the biosimilar for FDA approval. The agency is not required to follow the suggestions of its panels, though it commonly does.

The stateside delay is unlikely to spell a major disruption to the pair's global plans, as Remicade, which brings in roughly $8.4 billion around the world each year, isn't slated to lose U.S. exclusivity until 2018, anyway. Celltrion is doing its best to move that date forward, challenging some of J&J's patents in court, but the pharma giant is battling back with legal claims of its own in an ongoing dispute.

Outside the U.S., Celltrion and Hospira, soon to be a division of Pfizer ($PFE), are rapidly pressing forward with their biosimilar. This week, they made landfall in 12 European countries, including the major markets of the U.K., France and Germany. Their antibody, which bears the generic name infliximab, targets the protein TNF and is approved to treat a wide array of autoimmune ailments including psoriasis, arthritis and inflammatory bowel disease.

The next frontier for biosimilars is the U.S., which has to this point lagged behind the rest of world in codifying a regulatory framework for the knockoff medicines. Novartis ($NVS) is slated to hit the market first, expected to win approval next month for a biosimilar of Amgen's ($AMGN) blockbuster Neupogen, which boosts white blood cell production and is often used in tandem with chemotherapy. And the company's Sandoz business, a global leader in biosimilars, is working up copies of the blockbusters Humira, Enbrel, Rituxan and Procrit.

Behind Novartis is Apotex, whose take on Neupogen is currently under FDA review. And Hospira, thanks to a recent deal with Pfenex ($PFNX), is working on a version of Roche's ($RHHBY) blockbuster eye drug Lucentis, while Celltrion is working up biosimilars of the same company's Herceptin and Rituxan.

Express Scripts ($ESRX) has said the U.S. healthcare system could save roughly ​$250 billion over the next 10 years thanks to the rise of biosimilars, but more bearish observers caution there's no guarantee physicians will prescribe them interchangeably with their reference products.

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