Claim Term's Ordinary and Customary Meaning Implicitly Disclaimed by Four Specification Statements: Federal Circuit

Practical Law Legal Update 1-539-1125 (Approx. 4 pages)

Claim Term's Ordinary and Customary Meaning Implicitly Disclaimed by Four Specification Statements: Federal Circuit

by Practical Law Intellectual Property & Technology

Background

The patents at issue, which have the same written description, relate to methods for producing pharmaceutical compositions comprising cell culture medium conditioned by cells grown in two-dimensional or in three-dimensional culture. The patents' description also states that the cells that condition the medium are cultured in monolayer, beads or in three dimensions. During prosecution, the patentee limited the claimed invention to pharmaceutical compositions comprising cell culture medium conditioned by animal cells cultured only in three-dimensions to overcome certain prior art.

SkinMedica sued Histogen for infringement for its production of dermatological products according to a method that begins as one or two dimensional growth on beads that then evolves into a three-dimensional growth phase in which the cells crawl off the beads.

The district court construed the claim term "culturing . . . cells in three dimensions" as "growing cells in three dimensions excluding in monolayers or on microcarrier beads." It found that the inventors defined that term by implication to exclude culturing on beads even though culturing cells in three dimensions on beads was known in the art at the time of the patent applications' relevant filing dates. The district court reached its conclusion because the patentees:

Plainly and repeatedly distinguished culturing with beads from culturing in three dimensions.
Expressly defined the use of beads as culturing in two dimensions.
Avoided anticipatory prior art by asserting that the conditioned medium produced by two dimensional cultures was inferior and chemically distinct from the conditioned medium produced by three dimensional cultures.

Based on this claim construction, Histogen moved for summary judgment of noninfringement, which the district court granted.

SkinMedica appealed solely on the district court's claim construction.

Outcome

The Federal Circuit affirmed the district court's claim construction, and the noninfringement summary judgment, based principally on four statements in the specification that the majority believed demonstrated a clear and unmistakable disavowal of the ordinary meaning of three-dimensional culturing so that it excludes culturing with beads.

The majority, Judges Clevenger and Prost, placed great weight on the intrinsic evidence in affirming the district court. The Federal Circuit noted that the patentees refer to beads five times in the intrinsic record. While one of those statements is irrelevant, in all of the other four statements the patentees clearly distinguished culturing beads from culturing in three dimensions. Specifically: in the written description, the patentees state that:

Cell lines grown as a monolayer or on beads, as opposed to cells grown in three-dimensions, lack cellular-level interactions which are characteristic of whole tissue in vivo. The majority construed this to mean that the patentees considered cells grown on beads to be different from cells grown in three dimensions.
Conventional conditioned cell culture medium, medium cultured by cell-lines grown as a monolayer or on beads, is usually discarded. The majority construed this to mean that beads produce an inferior cell culture medium.
The cells are cultured in monolayer, beads (i.e., two-dimensions) or, preferably, in three-dimensions. The majority construed this to explicitly define beads as a two-dimensional culture method despite the fact that culturing cells in three-dimensions on beads was known in the art.
The cells may be cultured in any manner known in the art including in monolayer, beads or in three-dimensions and by any means. The majority construed this to differentiate cells grown in three dimensions.

The majority also brushed aside the patentees other arguments noting that:

Their argument that "three dimensional framework" as used in the patents includes beads:
- ignores their express restriction of that term to a "three dimensional scaffold"; and
- does not explain how beads could be a "three dimensional scaffold".
The patentees' reliance on a document incorporated by reference into the written description would not trump the clear disclaimer because they did not specifically refer to culturing with beads when referring to the reference but specifically referred to that reference when trying to explain other terms.
Another reference on which the patentees wanted to rely was not part of the intrinsic record and the patentees provided no context for it.
An expert witness's testimony was inconsistent with the intrinsic record and his opinions were conclusory and incomplete.

Chief Judge Rader dissented, arguing that these four references are ambiguous and do not meet the requirement that the patentee unmistakably and unambiguously disavow the ordinary meaning of the claim term.

Practical Implications

This case highlights:

The importance of the need to carefully draft the patent specification and claims to consider how a party attacking the patent will attempt to limit the desired claim breadth.
That a disclaimer of claim scope does not have to be explicitly recited.

Patentees should also be mindful that the use of the term "i.e.' in the specification may signal an intent to define the word to which it refers.

Court Documents

SkinMedica, Inc. v. Histogen Inc., No. 2012-1560 (Fed. Cir. Aug. 23, 2013).

Claim Term's Ordinary and Customary Meaning Implicitly Disclaimed by Four Specification Statements: Federal Circuit | Practical Law