Amgen doubles down on bid to block Novartis' biosimilar Neupogen

It's official: Amgen ($AMGN) is appealing last week's ruling in a fight over biosimilar Neupogen. The California-based biotech, aiming to protect its $1.2 billion branded drug, wants to bar Novartis ($NVS) from launching its biosimilar version, Zarxio.

On Friday, a San Francisco judge nixed Amgen's request for an injunction against a Zarxio launch. Naturally, Amgen wants the appeals court to reconsider. Whether Novartis' Sandoz unit would roll out its biosimilar in the meantime isn't clear, particularly because Amgen claims Zarxio steps on a Neupogen patent.

According to the order from U.S. District Judge Richard Seeborg, Sandoz had agreed with Amgen to delay its Zarxio launch until April 10 or a legal judgment in its favor, whichever came first. Sandoz also agreed to give Amgen a 5-day warning about its launch.

Novartis' Sandoz unit last month became the first drugmaker to win U.S. approval of a biosimilar product. Because it's on the bleeding edge, Zarxio is sort of a legal guinea pig. Sandoz has to cool its heels while the courts sort through the U.S. legal framework on biosims.

Part of that framework involves a so-called patent dance, which Seeborg declared optional last week. But that doesn't mean Sandoz is completely free to start selling Zarxio. Amgen points out that Seeborg's order didn't address Amgen's patent claims. If the Swiss drugmaker rolls out its Neupogen copy, and a court later decides that the biosim infringes Amgen's patent, Sandoz could owe Amgen reimbursements and penalties.

Meanwhile, the rest of the pharma industry is watching closely. Biosimilars and their place in the U.S. market--particularly the discounts they'll offer payers--are hot issues these days. Zarxio's experience in the courts, and later, on the market, could shed some light on those burning questions.

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