Amgen Files Cross-Appeal in Ongoing Battle Over Epoetin Alfa

In 2017, a federal jury found that Hospira had infringed on Amgen’s US Patent Number 5,856,298, which covers erythropoietin, in producing batches of a biosimilar epoetin alfa, now approved as Retacrit.

At the time, the court had ordered Hospira to pay Amgen, the reference product sponsor, $70 million in damages.

Since then, the Delaware district court entered final judgement, in September 2018, against Hospira. The judgement included an additional $10 million in pre-judgement interest, plus post-judgement interest from September 2017 until Hospira satisfies the final judgement, computed daily and compounded annually at a rate of 1.31%.

The damages were decided based on the jury verdict in 2017 that Hospira had infringed upon an Amgen process patent by manufacturing 14 batches of erythropoietin outside of the protection of the Safe Harbor Act. Hospira had unsuccessfully argued during the trial that its batches of the drug were part of its FDA approval process, and thus protected under safe harbor.

After receiving the final judgement rule, Hospira had 30 days to respond, during which the biosimilar manufacturer filed an appeal to the Federal Circuit in Delaware.

Subsequently, Amgen filed a cross appeal on October 15, 2018. The appeal challenges, among other things, the district court’s previous judgement that Hospira had not infringed on another patent named in the original suit, US Patent Number 5,756,349, which covers the production of erythropoietin. The appeals have since been consolidated into a single case.

Due to the filing of a cross-appeal, there will be 4 rounds of appellate briefing, and Hospira’s opening brief is due on December 10, 2018.

To date, in Europe there are currently 3 biosimilar versions of epoetin alfa available on the market, sold as Silapo, Retacrit, and Epoetin Alfa Hexal/Abseamed/Binocrit. Conversely, the United States has only 1 approved biosimilar epoetin alfa, Retacrit, though no launch date has been made available in light of ongoing litigation.