Federal Circuit Notes High Burden Of Invoking Inherency For Obviousness

In Par Pharmaceutical Inc. v. Twi Pharmaceuticals, Inc., the Federal Circuit vacated and remanded the district court decision holding the Par claims at issue obvious. The district court decision rested in part on the doctrine of inherency, but Twi did not establish that the property at issue "necessarily must be present" in the product rendered obvious by the prior art. In reaching this decision, the Federal Circuit emphasizes the "high standard" required to invoke the doctrine of inherency in an obviousness context.

The Patent at Issue

The patent at issue was Par's U.S. Patent No. 7,101,576, directed to methods of using megestrol:

1. A method of increasing the body mass in a human patient suffering from anorexia, cachexia, or loss of body mass, comprising administering to the human patient a megestrol formulation, wherein: