Big question for Pfizer: Will Enbrel's EU biosim bring on the pain?

Amgen ($AMGN) and Pfizer's ($PFE) Enbrel officially has a biosimilar rival in Europe. And if the rollout goes anything like the recent EU launch of Remicade copy Remsima, the blockbuster brand will be in trouble.

Approved by the European Commission, the Enbrel knockoff from Samsung Bioepis will be sold by U.S.-based Biogen ($BIIB). The Cambridge, MA, company plans to roll it out gradually across the 28 EU member states and Norway, Iceland and Liechtenstein, Reuters reports.

Biogen will be seeking the same success Pfizer's Hospira and Celltrion have found with Remsima, whose launch began in most major markets in the second quarter of last year. In Q3, market share for Merck's ($MRK) Remicade brand slipped to 90% from 95%, with sales sinking 13%. And in December, Bernstein analyst Ronny Gal wrote in a note to investors that Remsima's slice of the pie in the key U.K. and German markets had pushed to 15%.

With Biogen and Samsung hard at work on a copy of that drug, too, he forecast that Remicade biosimilars could gobble up 40% of share by the end of 2017.

Pfizer, on the other hand, is hoping for a different outcome. Enbrel racked up $3.85 billion outside the U.S. and Canada for the pharma giant in 2014, and those are revenues it would like to hang onto.

As Enbrel's U.S. marketing partner, Amgen will face its own competition soon enough. Last fall, Novartis' ($NVS) Sandoz unit said the FDA had accepted its regulatory submission for a potential biosim of the anti-TNF behemoth. The South San Francisco, CA-based drugmaker brought in $4.4 billion in Enbrel sales in 2014.

Meanwhile, Amgen, like Pfizer, is working to offset its future biosimilar losses by rolling out copycat meds of its own. Last week, though, the U.S. Patent and Trademark Office dealt the Big Biotech a setback, declining to review a pair of formulation patents on target drug Humira from AbbVie ($ABBV).

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