By Donald Zuhn —

On Wednesday, the Federal Circuit reversed a District Court judgment that U.S. Patent No. 5,401,741 (the ‘741 patent) was not invalid.  In particular, the Federal Circuit held that the District Court clearly erred in determining the level of one of ordinary skill in the art, and as a result, erred in finding the ‘741 patent valid as nonobvious.

Plaintiffs-Appellees Daiichi Sankyo Co., Ltd. and Daiichi Sankyo, Inc. (Daiichi Sankyo) own the ‘741 patent, which relates to a method for treating bacterial ear infections by topically administering the antibiotic ofloxacin into the ear.  Seeking approval to generic ofloxacin ear drops, Defendants-Appellants Apotex, Inc. and Apotex Corp. (Apotex) filed an Abbreviated New Drug Application (ANDA) with the FDA.  In response, Daiichi Sankyo sued Apotex for infringement of the ‘741 patent.

At trial, Apotex argued that the ‘741 patent was invalid as obvious in view of Ganz, 1986, "Gyrase inhibitor in the local treatment of the chronically infected middle ear following surgery," HNO 34:511-14.  According to Apotex, the Ganz reference taught the use of ear drops containing the gyrase inhibitor ciprofloxacin to treat middle ear infections, and therefore, rendered the use of ofloxacin – also a gyrase inhibitor – obvious.

In finding the ‘741 patent valid as nonobvious, the District Court first determined the level of ordinary skill in the art – the second of the four Graham factors.  Apotex had argued that one of ordinary skill in the art would be "a person engaged in developing new pharmaceuticals, formulations and treatment methods, or a specialist in ear treatments such as an otologist, otolaryngologist, or otorhinolaryngologist who also has training in pharmaceutical formulations."  The District Court, however, concluded that a person of ordinary skill in the art "would have a medical degree, experience treating patients with ear infections, and knowledge of the pharmacology and use of antibiotics," and thus, would be "a pediatrician or general practitioner."  Because the Ganz reference recommended that "[gyrase inhibitors] should be used only in difficult cases and exclusively by the otologist," and because the District Court had concluded that a person of ordinary skill in the art was a pediatrician or general practitioner and not an otologist, the District Court rejected Apotex’ argument that the use of the gyrase inhibitor ofloxacin to topically treat bacterial ear infections was obvious.

In reversing the District Court’s finding of validity, the Federal Circuit determined that the District Court had clearly erred in determining the level of one of ordinary skill in the art.  The Federal Circuit first observed that the inventors of the ‘741 patent were specialists in drug and ear treatments, and not pediatricians or general practitioners.  The Court also noted that the ‘741 patent described the testing of ofloxacin on animals, and that animal testing was traditionally outside the realm of a pediatrician or general practitioner.  Finally, the Federal Circuit stated that while a pediatrician or general practitioner could prescribe ofloxacin, he or she would not have the training or knowledge to develop the claimed compound.  After determining that the correct level of skill in the art was the one advocated by Apotex, the Federal Circuit concluded that in view of the evidence of record, the ‘741 patent was invalid as obvious as a matter of law.

Daiichi Sankyo Co. v. Apotex, Inc. (Fed. Cir. 2007)
Nonprecedential disposition
Panel: Chief Judge Michel, Senior Circuit Judge Archer, and Circuit Judge Dyk
Opinion by Senior Circuit Judge Archer

Additional information regarding this case can be found at the Orange Book Blog.