The Federal Circuit Upholds Daiichi’s injunction Against Lupin’s bid for Approval of Generic Levofloxacin

On May 10, 2010, the Federal Circuit upheld the grant of an injunction against Lupin Pharmaceuticals, who sought to invalidate the Patent Term Extension on Daiichi’s 703 patent covering levofloxacin. Levofloxacin is a quinolone class antibiotic, and is the S-(-) enantiomer of ofloxacin, which has been separately patented and FDA approved as an antibiotic.

In May of last year, Sughrue attorneys Mark Boland, Mike Dzwonczyk and Keiko Takagi prevailed on cross-motions for summary judgment directed to the validity of the ‘703 patent term extension. On appeal, Lupin argued that levofloxacin was an “active ingredient” of the previously marketed racemate ofloxacin, and therefore was the same “drug product” as ofloxacin. Since ofloxacin had been previously approved by the FDA, Lupin argued that permission to market and use levofloxacin was not “the first permitted commercial marketing or use of the product” as required by §156(a)(5)(A).

But the Federal circuit disagreed, stating that under FDA and PTO practices, levofloxacin was separately patentable, separately approved, and considered by the FDA as a separate drug product from ofloxacin. The court also rejected Lupin’s argument that its proposed statutory construction was supported by legislative changes in 2007, stating that “Lupin’s interpretation would change the long-standing term-extension policy of the FDA and the PTO; such a far-reaching change is not achieved by legislative silence.”

Sughrue’s representation of Daiichi in ANDA litigations involving the ‘703 patent began in 2002. The Federal Circuit’s decision in Lupin is the latest in a series of unsuccessful challenges to the ‘703 patent, and removes another prospective barrier to Daiichi’s proprietary position on levofloxacin. The ‘703 patent term extension expires December, 2010 and pediatric exclusivity covering levofloxacin is set to expire June, 2011.