In a citizen petition, AbbVie has challenged the Food and Drug Administration’s (FDA’s) approach to biosimilar labeling, as implemented in the agency’s recent approval for Zarxio (filgrastim-sndz) as a biosimilar to Neupoen (filgrastim). As we previously blogged, the prescribing information FDA approved for Zarxio seems to follow a “generic drug” model; the Zarxio labeling is