Court Orders FDA To Suspend Approval Of Norbrook’s New Bovine Drug
The manufacturer, Norbrook Laboratories of Lenexa, Kan., received FDA approval March 29 of an Abbreviated New Animal Drug Application for Enroflox 100 (enrofloxacin), a generic version of Bayer HealthCare’s Baytril 100.
Bayer won a temporary restraining order April 12 that suspended the FDA’s approval of Enroflox and the label. Bayer, based in Shawnee Mission, Kan., contended that labeling the administration of Enroflox as a multiple-dose regimen would be ignored by practicing veterinarians, who instead would deliver a single high dose, harming sales of Baytril 100, which has single-dose approval.
Three cattle veterinarians retained by Bayer concluded that the generic drug, labeled for multiday administration, "would be used in a single high dose, notwithstanding the instructions on the label.”
"The uncontroverted record evidence is that the generic product is reasonably certain to be used off-label in a single high dose,” Bayer asserted in court documents.
The U.S. District Court in Washington, D.C., issued the temporary restraining order and scheduled an April 25 hearing on Bayer’s motion for a preliminary injunction.
A Norbrook spokeswoman declined to comment.
Bayer began marketing Baytril 100, a fluoroquinolone antibiotic, in 1998 as a single high-dose treatment, which the company described as a revolutionary development.
"For many years the conventional wisdom was that [bovine respiratory disease] had to be treated by administering multiple low doses of antibiotic—a time-consuming, expensive and cumbersome practice,” the company noted.
Norbrook submitted its Abbreviated New Animal Drug Application for generic Baytril 100 in 2008, beginning a five-year process that ended with the FDA’s approval last month.