United States: Claim Construction: The Dictionary/Specification Dichotomy

Companies understand that in order to protect their technology from competitors, the company must have a strong patent portfolio. However, achieving this goal is requiring greater levels of drafting sophistication and strategy. It has become increasingly clear, by the recent case ruling in Merck & Co., Inc. v. Teva Pharmaceuticals USA, Inc., just how important it is to have a well drafted patent document that has clearly defined claim terms. At issue in the Merck case was the meaning of the apparently simple term "about" in the claims and what the patentee asserted was the meaning of this term as defined in the specification. The Federal Circuit’s ruling on the legally operative meaning of this term emphasizes the critical need for the patentee to exercise caution in drafting patent applications where a term in the claim is redefined from its common meaning.

Numerous court decisions have held that claim construction requires terms used in the claims to be given their "ordinary", "accustomed", or "dictionary" meaning unless the patentee has chosen to otherwise clearly define the terms in the patent specification or prosecution history. It is well settled that a patentee can act as his own lexicographer by choosing his own definition of a term and using it as he wishes so long as he remains consistent in its use and makes the meaning clear. The law provides the patentee with this opportunity because the public may not be schooled in the terminology of the technical art or there may be more than one way to interpret the structure or concept that is being claimed. However, the lexicographer privilege has recently come under criticism by some courts that have viewed it as imposing on the interpreter of the claims the burden of determining, through study of the patent’s specification or prosecution history, whether the patent gives an unconventional meaning to a term that otherwise has an established meaning. Most recently, courts have questioned what sources should be consulted during the claim construction process to determine the legally operative meaning of the words in a claim.

In a recent decision, the Federal Circuit reversed an August 2003 district court ruling thereby invalidating Merck’s patent on Fosamax, an osteoporosis treatment that was Merck's second-best-selling drug. In a statement to the press after the verdict, Merck said that it disagreed with the court's ruling "and is considering its options, including a request for reconsideration by the court of appeals." Thus, Merck is considering asking the Supreme Court to review the ruling. It is doubtful that the Supreme Court would do so, because it rarely accepts patent cases.

The district court held that Merck had acted as its own lexicographer and in the specification had redefined the ordinary meaning of the term "about". Merck had taken the position that it acted as its own lexicographer and that the claim term "about 70 mg of alendronate monosodium trihydrate on an alendronic acid base" should mean exactly 70 mg of alendronic acid. Ordinarily, of course, the term "about" would mean "approximately", but the district court sided with Merck and ruled that the term "about" meant "exactly". Relying on this latter construction of the term "about", the district court found the prior art cited against the patent to be insufficient to invalidate the patent based on anticipation or obviousness. Teva’s allegations that the claims at issue were invalid was based on (1) anticipation by a July 1996 Lunar News article and (2) obviousness in light of an April 1996 Lunar News article combined with the July 1996 article. However, the district court found the patent valid and infringed by Teva’s Abbreviated New Drug Application ("ANDA"), effectively delaying Teva’s FDA approval of the ANDA until the Merck patent expires.

On appeal, the Federal Circuit addressed claim construction and obviousness. The Federal Circuit opined that when construing a claim term, the court must first consider the intrinsic evidence, starting with the language of the claims. "General claim terms should be construed consistently with their ordinary and customary meanings, as determined by those of ordinary skill in the art." In this regard, the specification is reviewed to determine whether the patentee acted as his own lexicographer of a term that already has an ordinary meaning. However, any "statement in the specification must have sufficient clarity to put one reasonably skilled in the art on notice that the inventor intended to redefine the claims term."

Merck’s position was that the following passage from the specification redefined "about" to mean "exactly":

The Federal Circuit disagreed and held Merck’s definition of "about" is ambiguous in that this passage was not clear enough to put one of skill in the art on notice that the ordinary meaning of "about" was redefined. The term "about" was amenable to two interpretations. The Federal Circuit stated that, under Merck’s construction, the phase "about 70 (or 35) mg" means that one should administer approximately 70 (or 35) mg of the derivative compound, such that the end result would be that the patient received exactly 70 (or 35) mg of active compound. In other words, the phrase "about 70 (or 35) mg" modifies the quantity of the derivative compound rather than the resulting active compound. However, according to Teva, the phrase could also be construed to mean that "about 70 (or 35) mg" refers to the amount of resulting active compound rather than the amount of the derivative compound administered. The term "about" would then serve to modify the quantity of the active compound in a way consistent with its ordinary meaning of "approximately". Given that the passage was agreeable to both interpretations, the Federal Circuit held that Merck did not clearly set out its own definition of "about".

The Federal Circuit further decided the invention was obvious in light of earlier published articles. In short, the Federal Circuit opined that the district court clearly erred in not (1) distinguishing the claimed invention from the two Lunar News articles, (2) ascertaining the required motivation to combine references to achieve the claimed invention which clearly suggested the dosages described in the articles, (3) determining the probative value of the articles, and (4) weighing the secondary considerations or Merck’s commercial success. Judge Rader wrote a dissent in which he made two specific points: (i) that the majority erred in its analysis of the lexicographer doctrine and (ii) that the majority should have given some deference to the lower court's decision.

The Merck decision warns the patentee to be clear when defining claim terms. It is hoped that another case pending before the Federal Circuit will provide additional clarification regarding the process of defining terms used in the claims. In Phillips v. AWH Corp., which was heard en banc on February 8, 2005, the Federal Circuit prudently chose to re-examine and consider seven issues: (1) how and to what extent various types of evidence, particularly the specification and dictionaries, serve the public notice function of patent claims; (2) how the specification should be used to interpret claims without impermissibly importing limitations into the claims; (3) how and to what extent various types of evidence, particularly the specification and dictionaries, should be used for claim construction; (4) whether the two approaches (dictionary and specification) should be treated as complementary methodologies such that there is a dual restriction on claim scope, and a patentee must satisfy both limiting methodologies in order to establish the claim coverage it seeks; (5) when, if ever, should claim language be narrowly construed for the sole purpose of avoiding invalidity under, e.g., 35 U.S.C. §§ 102, 103 and 112; (6) what role should prosecution history and expert testimony by one of ordinary skill in the art play in determining the meaning of the disputed claim terms; and (7) what deference, if any, the Federal Circuit should give to a district court's claim construction. Thus, this decision is expected to provide additional guidance on the proper approach to construing patent claims.

In light of the fact that it is not uncommon for the patentee to use a word to mean something different than its dictionary definition and because a patent’s specification can be ambiguous, it is advisable that the patentee and his counsel work closely together to clearly define claim terms having technical, scientific, or multiple meanings.

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