Amgen's Neupogen (Filgrastim) will lose its key patent in major markets in 2006 opening the market for generics. Amgen is already preparing itself for this major patent loss by concentrating its marketing efforts on Neulasta (Peg-Filgrastim) its once-per-cycle long acting pegylated product and by offering little or no support to Neupogen.

The market for Erythropoietin is very lucrative. Marketing costs are low due to the well-defined patient population and distribution costs are low due to the limited distribution outlets. Since the market is a virtual oligopoly barriers to entry are high thus insuring high profitability.