Credit: AP Photo/Reed Saxon

Thousand Oaks, California–based Amgen is shuttering its Epogen (epoetin alfa) manufacturing facility in Longmont, Colorado, a sign that the 20-year anemia drug's dominance has ended. Declining US sales of the erythropoietin stimulating agent (ESA) and its pending patent expiration are likely factors in the decision. Epogen accrued roughly $40 billion in sales since the drug was approved for treating anemia in kidney patients on dialysis. But in 2011 sales of Epogen were $2 billion, down from $2.6 billion in 2009. Amgen also reported a 28% fall in demand during the first half of 2012. Sales may have never recovered from the safety issues that emerged in 2010 when high doses of Epogen and its sister product Aranesp (darbepoetin alfa) were linked to serious adverse effects, including death, prompting labeling changes. But analysts say falling sales are mostly due to bundling rules introduced by Medicare in 2011, whereby a single payment covers all dialysis services including drugs and diagnostics. “Since Epogen is one of the more expensive drug treatments for dialysis patients, it is a logical place for utilization cuts, particularly since it was widely believed that dosages had increased in recent years partly due to more favorable reimbursement rather than pure medical necessity,” says Morningstar analyst Karen Andersen, based in Chicago. Amgen faces competition from Affymax's newly approved Omontys (peginesatide), a once-a-month PEGylated synthetic dimeric form of erythropoietin (Nat. Biotechnol. 30, 377–379, 2012). And Epogen's imminent patent expiry in 2013 could see biologically similar drugs such as Novartis' Binocrit (epoetin alfa) and Roche's Mircera, a PEGylated epoetin beta, gaining ground. Amgen has taken steps ahead of its rivals by signing contracts earlier this year with dialysis providers DaVita, of Denver, and Fresenius Medical Care, of Waltham, Massachusetts, that together account for two-thirds of US dialysis patients. The Longmont plant's doors will still close in 12–15 months, but until then Amgen intends to ramp up production at the 485-employee facility. “This way, Amgen is simultaneously prepared for best- and worst-case scenarios and able to quickly shutter the facility entirely or ramp up production, depending on the strength of these emerging threats,” Andersen says. “Epogen will certainly be one of the first test cases for the traction of biosimilars in the US market.”