Summary of: Key Pharmaceuticals v. Hercon Laboratories Corporation
United States Court of Appeals for the Federal Circuit (Fed. Cir.) Decided November 25, 1998
Issue Discussed: Meaning of "Pharmaceutically Effective Amount" in a Patent Claim

SUMMARY
How many times have you been presented with a patent, read the document, and then been confronted with the claims. The claims, those pesky numbered paragraphs at the end of the patent document, define what the patent protects and what exclusive right the patent owner has. The claims can be filled with unusual structure, terms, formulas, words and phrases that can lead the untrained reader to question what language is being used.

You are not alone. Interpreting the meaning of patent claims has been described by notable judges as among the most difficult tasks in the law. The meaning of the words in the claims stems from their plain meaning in the field, the meaning set forth in the rest of the patent document and the file history generated during prosecution of the patent before the United States Patent and Trademark Office (USPTO).

At times, certain claim language becomes "trendy" and becomes prevalent in a great number of patents. One such term is a "pharmaceutically effective amount," the meaning of which was the subject of this case.

EXECUTIVE SUMMARY:
In this patent infringement suit, the Fed. Cir. addressed the issue of the meaning of a "pharmaceutically effective amount" in a claim directed to "an adhesive transdermal layer for sustained release of a pharmaceutically active drug to the skin of a human patient." The Fed. Cir. noted that it is "quite sensible to look to the FDA to determine what amounts are considered pharmaceutically effective," a term often used in biotechnology patent. The Practice Pointer to be gained from this case is that valuable information in support of patentability can be obtained from a wide variety of reputable sources, including Federal Agencies.

THE LAW
Claim interpretation is a matter for the judge and is the fundamental basis of the patent examining procedure before the United States Patent and Trademark Office (USPTO). The judge can use a variety of sources of "intrinsic evidence" to interpret what terms in a claim mean, including the patent specification and the file history build during patent acquisition before the (USPTO). The judge can also hear "extrinsic evidence," such as expert witness testimony, dictionaries and other learned sources as background information. Importantly, the Fed. Cir. recognized that "a trial court is quite correct in hearing and relying on expert testimony on an ultimate claim construction question in cases in which the intrinsic evidence (i.e., the patent and its file history - the 'patent record') does not answer the question."

IMPORTANCE OF THE CASE
This case is particularly important to the biotechnology community because the term "pharmaceutically effective amount" is common in a variety biotechnology patent claims. The recognition by the Fed. Cir. that extrinsic evidence can be used to determine the meaning of such a common term would tend to add value to claims that use this term without a highly explicit meaning of that term.
This summary is provided for general information only and is not legal advice. Individuals and entities involved in intellectual property should consult with a patent attorney or patent agent to fully address issues of intellectual property law based on an analysis of the particular facts of a case.