Claim Terms Must Be Understood in Context of Invention

Case: TAP Pharm. v. Owl Pharm. (Fed. Cir. 8/18/05 - No. 03-1634, 03-1634).

The One Sentence Summary: In this dispute about patents for a prostate cancer drug, Federal Circuit affirmed claim interpretation, inequitable conduct, and literal and doctrine of equivalents infringement rulings by the district court.

Federal Circuit Holdings:

• The Federal Circuit affirmed the district court's grant of summary judgment of infringement on two patents for a prostate cancer drug. The district court properly construed the claim term "comprising a copolymer . . . of lactic acid and . . . of glycolic acid." The district court found that this term was not limited to direct polymerization from lactic acid or glycolic acid, holding rather that the claimed polymers could be made by a different method such as the "ring-opening" method in which lactic acid and glycolic acid are first converted into cyclic dimers, known as lactide and glycolide. The district court properly interpreted this claim in light of the specification, treatises, expert testimony on the understanding of one skilled in the art and the prosecution history.
• The district court did not err in finding no inequitable conduct in the submission of a reference called the Kent Application. "The district court found that the Kent application was not material to the patentability of the claims of those patents and that TAP did not intend to deceive the PTO by withholding the application until after issuance of the notice of allowance for the ’721 patent."
• On the cross appeal, the district court properly interpreted the phrase “particles containing a water-soluble drug” to require the presence of a drug-retaining substance along with the drug. The non-technical word "containing" must be understood based on its context:

  As the district court correctly pointed out, a word describing patented technology takes its definition from the context in which it was used by the inventor. See Anderson v. Int’l Eng’g & Mfg., Inc., 160 F.3d 1345, 1348-49 (Fed. Cir. 1998). While the term "containing" is not a technical term, the term is essential in helping to describe the patented technology.

• Based upon this claim interpretation, there was no literal infringement, and application of the doctrine of equivalents would vitiate the limitation.