When the biosimilar pathway was enacted in the US, there were some shared assumptions about which products might be first to win FDA approval using the abbreviated pathway, and which might take more time.
Taking Biosimilars Down A PEG: Why Copying Neulasta Isn’t So Easy
Biosimilar sponsors are 0-3 so far in attempts to win US FDA approval for copies of Amgen’s pegfilgrastim (Neulasta). FDA’s recent review of a novel clotting factor formulation offers a clue why it is turning out to be harder than it seems to copy a pegylated protein.