Jonathan A. Platt

“When I use a word, it means just what I choose it to mean — neither more nor less.” So said Humpty Dumpty in Lewis Carroll’s Through the Looking Glass. That quote has a special resonance for me since it was often used by the late Patent Attorney John Renner (the Renner of “Renner Otto”) in his appeal briefs, to complain about selective interpretations employed by patent examiners.

Last month a judge saw fit to quote Lewis Carroll in a claim-construction opinion in an infringement suit, Alnylam Pharma. v. Pfizer, (D.Del. Aug. 9, 2024). The judge’s invocation of Lewis Carroll was part of a screed against claim preamble interpretations that read words out of a claim when determining its scope.

A claim preamble is the opening statement of the claim, describing the type of claim (method, system, apparatus, or composition), and the nature of the claim (its field of art). The preamble is followed by a transitional phrase (usually “comprising” or “consisting essentially of,” or some equivalent term), and a body of the claim, the latter of which sets forth the features of the claim. There is no doubt that the features recited in the body of the claim limit claim scope, but what about the words of the preamble – do they limit the scope of the claim?

Maybe. The MPEP unhelpfully states that the “determination of whether a preamble limits a claim is made on a case-by-case basis in light of the facts in each case; there is no litmus test defining when a preamble limits the scope of a claim,” MPEP 2111.02. There is a general division between structural limitations in the preamble (which are considered to limit scope) and recitations of purpose or use (which do not limit scope). Id. A related distinction may be drawn from a long series of Federal Circuit cases, that preamble statements of purpose or intended use do not limit the claim scope, while preamble statements are limiting if they are necessary “to give life, meaning and vitality to the claim.” See, e.g., Marrin v, Griffin, 599 F.3d 1290, 1294-96 (Fed. Cir. 2010).

The claim construction in Alnylam involved two claims that included the word “vaccine” only in their preambles (in addition to a lot of chemistry talk about lipid particles in their bodies). The parties had no dispute as to meaning of the word “vaccine,” only on whether its use in the preamble limited the scope of the claims being construed. (Other claims in the same patent had preamble language reciting a “pharmaceutical composition,” a broader term than “vaccine.”) The position of Alnylam, the patent holder, was that (as stated by the judge in a hearing) “what is accused of infringing … doesn’t have to be a vaccine.” This goes beyond Humpty Dumpty, to assert that a word used means nothing at all.

The judge opined that while the patentee’s position had its basis in Federal Circuit case law, he felt that it transported him to “a nonsensical wonderland.” (Citing Alice from Through the Looking Glass: “If I had a world of my own, everything would be nonsense. Nothing would be what it is, because everything would be what it isn't.”) He railed against the “Mad Hatter logic” that a claim explicitly reciting that it is to “a vaccine,” albeit in its preamble, would not be construed to cover only vaccines. In his construction, the judge held that the preamble term “vaccine” limited the scope of the claims under consideration. Finally, in a concluding section, he urged “the Federal Circuit to jettison its rulings that treat language in the preamble of a patent claim as not limiting the scope of that claim.”

Patent law only seems sometimes like a nonsensical wonderland. It is important to have an experienced guide to help one navigate through the patenting thicket. At Renner Otto we have an array of charming and knowledgeable White Rabbits to aid you in your journey.