Addressing the issue of implicit disclaimer/redefinition, the U.S. Court of Appeals for the Federal Circuit upheld a district court’s grant of summary judgment of non-infringement, agreeing that the intrinsic record effected a clear and implicit disclaimer of culturing with beads as not being within the scope of the claimed invention, even though the written description never explicitly redefined the disputed claim phrase to exclude the use of beads.  SkinMedica, Inc. v. Histogen Inc., Case No. 12-1560 (Fed. Cir., August 23, 2013) (Prost, J.) (Rader, C.J., dissenting).

SkinMedica brought suit against Histogen for allegedly producing dermatological products according to methods covered by claims of two of its patents.  The claims of both patents include a limitation that the cell culture medium used in the inventions must be conditioned by “culturing . . . cells in three-dimensions.”  The district court construed the disputed phrase, using an exclusionary limitation, to mean “growing . . . cells in three dimensions (excluding growing in monolayers or on microcarrier beads).”  The exclusionary language was based on a finding of disclaimer.  Following claim construction, the district court granted summary judgment of non-infringement.  SkinMedica appealed.

The Federal Circuit affirmed the claim construction, while acknowledging that the ordinary meaning of “culturing . . . cells in three-dimensions” would include the use of beads.  The Federal Circuit, however, found that “[i]n the written description, the patentees plainly and repeatedly distinguished culturing with beads from culturing in three-dimensions.  They expressly defined the use of beads as culturing in two-dimensions.  And they avoided anticipatory prior art during prosecution 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.”  To support its conclusion, the panel majority went into some detail as to four references to “beads” in the specification and statements made by the patentees during prosecution.  In particular, the majority noted the disjunctive use of “or” and “as opposed to,” and the use of “i.e.” as an intent to redefine/disclaim the use of beads. 

The Federal Circuit rebuffed SkinMedica’s arguments that there was no disclaimer.  The Federal Circuit dismissed a statement in the specification that was relied upon by SkinMedica as providing a broad definition of “three-dimensional framework” for failing to explicitly include beads, and found that a publication incorporated by reference was not adequate to overcome the clear implicit disclaimer in the intrinsic record.  The Federal Circuit gave little weight to extrinsic evidence, particularly expert testimony that discussed beads as a beneficial three-dimensional culturing technique, noting it was conclusory and appeared to be in conflict with the plain language of the written description.  The Federal Circuit concluded that “[i]t is therefore clear from the intrinsic record that, although the inventors never explicitly redefined ‘culturing . . . cells in three-dimensions’ to exclude the use of beads, they affected a clear implicit disclaimer of culturing with beads from the scope of their claimed invention.” 

In dissent, Chief Judge Rader argued that the four references to beads in the specification “do not amount to an unmistakable and unambiguous disavowal,” and further “do not meet the exacting standard imposed by this court’s precedent.”  Chief Judge Rader explained that the patentee’s disjunctive/redefining uses of “beads” could be understood as discounting two-dimensional bead usage without necessarily excluding three-dimensional bead usage.  He also found that the expert testimony, when viewed as a whole, deserved great weight and respect.