ENDO PHARMACEUTICALS SOLUTIONS V. CUSTOPHARM INC.

Federal Circuit Summary

Before Moore, Linn, and Chen.  Appeal from the United States District Court for the District of Delaware.

Summary: A prior art reference does not inherently disclose the elements of a claim limitation if the prior art describes the performance of the elements but does not include a complete description of the elements. 

Custopharm Inc.’s  predecessor-in-interest submitted an Abbreviated New Drug Application for FDA approval to market a generic version of Endo Pharmaceuticals Solutions, Inc.’s (“Endo”) drug  Aveed®, a testosterone undecanoate (TU) intramuscular injection.  Bayer owns the two patents listed in the Orange Book for Aveed®.  Endo and Bayer sued Custopharm for infringement of the two patents.  Plaintiffs asserted only two claims, one from each patent, and Custopharm stipulated to infringement.  The district court held a four day bench trial on invalidity, and the district court determined that the asserted claims were not invalid as obvious.  Custopharm appealed. 

The patents-in-suit disclosed three primary elements: (1) 750 mg dosage of TU; (2) a 40% castor oil and 60% benzyl benzoate vehicle; and (3) a specific injection schedule.  First, regarding the 750 mg dosage of TU, Custopharm noted that the American Association of Clinical Endocrinologists (AACE) Guidelines stated that patients in prior art clinical studies were being overdosed based on its identified normal testosterone levels.  Therefore, Custopharm argued a skilled artisan would have been motivated to reduce the dosages identified in prior art.  The Federal Circuit rejected this argument because the FDA Guidelines were “the most prevalently applied guidelines in clinical practice” and, under those guidelines, the testosterone levels in the prior art clinical studies would have been deemed normal.  Indeed, the prior art clinical studies and the patents-in-suit cited the FDA Guidelines.  Also, the Court reasoned that Custopharm’s overdose theory “improperly assumes that the only solution to overdosed patients is to reduce dosage rather than extending the injection intervals.” 

As to the second element, Custopharm argued that the vehicle formulation was inherently disclosed because the prior art provides a “detailed recitation” of the composition’s pharmacokinetic performance, and it was later revealed that the same formulation identified in the patents-in-suit was used by the authors of the prior art.  Custopharm argued that a skilled artisan could derive the formulation based on its pharmacokinetic performance.  The Federal Circuit rejected this argument, and noted that “Custopharm’s own opening brief does not argue that the pharmacokinetic performance . . . can only be attributed to the claimed vehicle formulation.”  Further, there were many potential co-solvents in the prior art so it would not have been obvious that the prior art authors chose this particular formulation. 

As to the third element, Custopharm argued that a skilled artisan would have recognized that patients injected with 1000 mg TU as disclosed in the prior art were being overdosed and, therefore, the claimed injection schedule would have been obvious.  The Federal Circuit rejected this argument because it was predicated on Custopharm’s already rejected overdose theory.  Accordingly, the Federal Circuit affirmed the District Court’s finding of nonobviousness.

This case is: ENDO PHARMACEUTICALS SOLUTIONS V. CUSTOPHARM INC.

Editor: Paul Stewart

Written by:  Ari Feinstein and Nicole R. Townes