Skinmedica v. Histogen: If You Say it, It's So (The Accidental Lexicographer)

Category: Claim Construction 
 By: John Kirkpatrick, Contributor 
TitleSkinmedica, Inc., v. Histogen Aesthetics, LLC., 2012-1560, (Fed. Cir. August 23, 2013).
Issue"[T]he ordinary meaning of 'culturing . . . cells in three-dimensions' would reach the use of beads. The question is whether the patentees [...] defined 'culturing . . . cells in three-dimensions' to exclude the use of beads." Skinmedica, at *13 (text added).
HoldingBased on the clear language of the specification [which: (i) disclaimed the ordinary meaning of "culturing cells … in three dimensions"; (ii) had a patent incorporated by reference which did not particularly define said term; and (iii) had an unincorporated cited patent that served only as extrinsic evidence] and the statements made by the patentees during prosecution, we hold that the inventors of the ’494 and ’796 patents disclaimed beads as a method to culture the cells that condition the medium used in their claimed inventions. We accordingly affirm the district court’s construction of the term “culturing . . . cells in three-dimensions,” common to all the assert claims, as “growing . . . cells in three dimensions (excluding growing in monolayers or on microcarrier beads).”
Id. at *43 (text added).

Procedural HistorySkinMedica owns U.S. Patent Nos. 6,372,494 (’494 patent) and 7,118,746 (’746 patent) [and] filed a patent infringement suit against Histogen for producing dermatological products according to [the claimed] methods." Skinmedica, at *2 (footnote removed, text added). "[The district court] construed the phrase 'culturing . . . cells in three-dimensions' as 'growing ... cells in three dimensions (excluding growing in monolayers or on microcarrier beads).'" Id. at *8 (footnotes removed, text added). "The court held that summary judgment of noninfringement was appropriate because 'Histogen’s cell growth process, which uses beads, cannot infringe the disputed claim element as construed.' [...] SkinMedica filed a timely appeal of the district court’s grant of summary judgment. Id. at *10.
Prosecution History"During prosecution of the ’494 patent, the inventors limited their claimed inventions to pharmaceutical compositions comprising cell culture medium conditioned by animal cells cultured only in three-dimensions. They did so to overcome an anticipation rejection based on prior art (the 'Shipley' reference) that disclosed the use in a pharmaceutical composition of cell culture medium conditioned by animal cells grown in two-dimensions."
Skinmedica, at *3, 4.


Legal Reasoning (Prost, Clevenger)
Relevant Technology"A cell culture medium is an artificial environment, such as a liquid, that is outside the body ('in vitro') and 'suppl[ies] the components necessary to meet the nutritional needs required to grow cells.' [...] A 'conditioned' cell culture medium is one which has been incubated with cells. [...] [A] conditioned medium commonly includes [...] 'secreted proteins' produced by cells in the culture [...] [T]hose 'extracellular” proteins may be useful in the treatment of [...] 'wrinkles, frown lines, scarring and . . . other skin conditions.'" Skinmedica, at *2, 3 (footnotes removed, text added). "[T]he inventors discuss a system that is closer to achieving the goal of long term culture and proliferation of cells and that more closely replicates the valuable characteristics of whole tissue in vivo." Id. at *6. "According to the patentees, a novel and important aspect of their invention is the difference between the conditioned medium produced by cells cultured in two dimensions and in three-dimensions." Id. at *4.
Representative Claim"1. A method of making a composition comprising: (a) culturing fibroblast cells in three dimensions in a cell culture medium sufficient to meet the nutritional needs required to grow the cells in vitro until the cell culture medium contains a desired level of extracellular products so that a conditioned medium is formed; (b) removing the conditioned medium from the cultured cells; and (c) combining the conditioned medium with a pharmaceutically acceptable carrier to form the composition." Skinmedica, at *4.
1. Defining "Beads" in light of the Intrinsic Evidence
Legal Standards
Intrinsic Evidence, Generally"'The words of a claim are generally given their ordinary and customary meaning as understood by a person of ordinary skill in the art when read in the context of the specification and prosecution history.' [...] [W]e first look to, and primarily rely on, the intrinsic evidence, including the prosecution history and the specification—which is usually dispositive. Phillips, 415 F.3d at 1315 ('The claims, of course, do not stand alone. Rather, they are part of a fully integrated written instrument [...]')."  Skinmedica, at *12 (some citations and portions of internal quotations omitted, text added).
Disclaimer and Disavowal[I]f the specification reveals 'an intentional disclaimer, or disavowal, of claim scope by the inventor,' the scope of the claim, 'as expressed in the specification, is regarded as dispositive.' [...] Disclaiming the ordinary meaning of a claim term—and thus, in effect, redefining it—can be affected through 'repeated and definitive remarks in the written description.' [...] 'The specification acts as a dictionary when it expressly defines terms used in the claims or when it defines terms by implication.'" Id. at *13-14 (internal citations omitted, text added).
Lexicography"During claim construction, terms are not always afforded their ordinary meaning. [...] If the specification reveals 'a special definition given to a claim term by the patentee that differs from the meaning it would otherwise possess[,] . . . the inventor’s lexicography governs.' [...]" Id. at *13-14 (internal citations omitted, text added).
Plain Meaning of the Disjunctive Phrase: 'as opposed to'"[T]he patentees state: Cell lines grown as a monolayer or on beads, as opposed to cells grown in three-dimensions, lack the cell-cell and cell-matrix interactions characteristic of whole tissue in vivo. [...] The plain meaning of the disjunctive phrase, 'as opposed to,' is 'contrary or opposite to' or 'standing in opposition, contrast, or conflict.' Oxford English Dictionary 867, vol. X (2d ed. 1989). [...] SkinMedica, however, would like to limit the import of the disjunctive phrase by reading the passage as: 'Cell lines grown as a monolayer or ‘on [the surface of the] beads,’ as opposed to cells grown in three-dimensions.” [...] The plain words selected by the inventors exhibit a clear intent to distinguish between three-dimensional culturing and culturing in monolayer and on beads. [...] And there is no indication in the specification or prosecution history that the inventors believed beads could be used for both two- and three-dimensional culturing—as they used those terms in their patents. [...] Rather, as the patentees stated to avoid prior art during prosecution, 'conditioned medium obtained from . . . cells cultured in two-dimensions . . . [is] not identical, expressly or inherently' to 'medium obtained from the same cells cultured in three-dimensions.' [...] The plain import of the phrase '[c]ell-line grown as a monolayer or on beads, as opposed to cells grown in three-dimensions' is that, in context of the patents, cultures in which cells are grown on beads are distinct and different from cultures in which cells are grown in three-dimensions." Skinmedica, at *16-18 (text added).
Prosecution History Disclaimer"[The patentees state:] Conventional conditioned cell culture medium, medium cultured by cell-lines grown as a monolayer or on beads, is usually discarded [...] [The conclusion] is that 'cell-lines grown as a monolayer or on beads' are distinct from three-dimensional cultures because they produce 'conventional' media with inferior chemical compositions. [...] To overcome an anticipation rejection, the patentees argued that '[c]ulturing cells in three-dimensions results in the production of a conditioned medium having a different chemical composition than that of cells cultured by conventional means.' [...] They also explained that the two media were 'not identical, expressly or inherently' and differed, in part, by the abundance of growth factors and other cell metabolites.' [...] Such emphasis on a particular mode of operation, especially to avoid prior art, can operate as a disclaimer of the otherwise broad scope of a claim term." Id. at *18-20 (text added).
Use of Disjunctive "or" to Describe Alternatives[The patentees also state:] The cells are cultured in monolayer, beads (i.e., two-dimensions) or, preferably, in three-dimensions. [...] The disjunctive 'or' plainly designates that a series describes alternatives. [...] [W]e [have previously] recognized that the 'use of two terms as alternatives' functions as a redefintion of a term if that redefinition is 'so clear that it equates to an explicit one.' [...] They not only repeated such a disjunctive listing of culturing methods elsewhere in the specification, but also expressly chose to define beads as culturing in 'two-dimensions'—a definition that places beads in stark contrast to another method immediately following it in the list, 'three-dimensions.'" Id. at *21-22 (citations omitted, text added).
Deviating from Ordinary Meaning Based on Patentee's Unique use of the Term "Beads (i.e., Two-Dimensions)" in the Specification "[T]he 'phrase ‘beads (i.e, two-dimensions)’ explicitly define[s] beads as a two-dimensional culture method, despite that culturing cells in three-dimensions on beads was known in the art.' [...] [The] 'use of ‘i.e.’ signals an intent to define the word to which it refers.' [...] To SkinMedica, the phrase simply clarifies culturing beads in two-dimensions is different from culturing beads in three-dimensions. Any other reading, in SkinMedica’s view, would be inconsistent with the ordinary meaning of three-dimensional cultures, which includes the use of beads. [...] We do not believe that the patentees used the phrase 'beads (i.e., two-dimensions)' to signal that beads 'can' be a two-dimensional culturing method. That is a not a natural reading. The inventors go to great lengths [...] to explain dozens upon dozens of different ways to culture cells in three-dimensions, yet do not mention beads once in any of them. [...] And in the only places where the inventors mention culturing with beads in the specification, they clearly distinguish such culturing from growing or culturing cells in three-dimensions. [...] During prosecution, the patentees disclaimed medium conditioned by 'conventional means' and taught in the written description that cells grown on beads produce such 'conventional' medium. Reading 'beads (i.e., two-dimensions)' as definitional comports with the plain language of the specification as a whole and the inventors clearly expressed intent to differentiate the use of beads from three-dimensional culturing. While that result might be 'inconsistent' with the ordinary meaning of three-dimensional culturing, it is one that the intrinsic record here plainly demonstrates to be correct." Id. at *22-24 (text added). "[T]he definition that follows 'i.e.' here directly contrasts the term it is defining with another listed alternative (two- versus three-dimensions). [Further] to read 'i.e.' as showing intent to define [does not] exclude multiple embodiments clearly discussed throughout the claims [because] the use of beads is mentioned nowhere in the claims." Id. at *25 (text added).
2. Skinmedica's Arguments (i) Against Disclaimer of a Desired Interpretation, and (ii) for Extrinsic Evidence to Support the Desired Interpretation
(i) Arguments Against Disclaimer Unpersuasive
Spec. Defined Three-Dimensional Framework to Include Beads, but failed to Account for limiting "scaffold" feature"[SkinMedica argues:] 'The inventors knew that beads could be used in three-dimensional culturing. Their definition of a three-dimensional frame-work broadly encompassed ‘any material and/or shape.’' [...] Without explaining how beads are a 'three-dimensional scaffold,' SkinMedica’s reliance on the definition of “three-dimensional framework” is incomplete. If we were to simply ignore the scaffold restriction, any structure of any material and/or shape that allows for cell attachment and for cell growth in more than one layer would be swept into the definition." Skinmedica, at *31, 32 (text added).
Document Incorporated by Reference did Not Discuss 'Beads in Three-dimensions' with any Degree of Particularity"According to SkinMedica, the inventors also could not have disclaimed the use of beads because they stated in the written description that 'cells may be cultured in any manner known in the art' and incorporated Doyle into the specification." Skinmedica, at *33 (footnote removed). "It is clear from that passage that the inventors did not refer to Doyle in order to define what they meant by 'three-dimensional culturing' in their patent. They did not indicate their reference to Doyle was for that purpose; nor did they even refer with any detailed particularity to the passages in Doyle that [...] may have discussed three-dimensional culturing with beads. When the inventors wanted to use Doyle to explain the potential scope of terms they used, they did so specifically." Id. at *35, 36 (text added).
(ii) Extrinsic Evidence: General Citation to Another PatentA Reference Cited in the Specification, but not Incorporated by Reference, acts as Extrinsic Evidence"[The cited Seldon reference] is not part of the intrinsic record [...] It is not in the record on appeal [...] [and] is, at best, extrinsic evidence belatedly cited by Skinmedica in its reply brief. [...] However, SkinMedica’s tardiness has so shaded what light Seldon may have shed on the relevant art here that we cannot fairly consider it. We simply cannot decipher the import of the reference without adequate context. SkinMedica has waived its ability to rely on the reference for claim construction purposes on appeal." Id. at *38.
(ii) Extrinsic Evidence: Expert Testimony
Legal Standard"When construing claim terms, [expert testimony] is 'less reliable than the patent and its prosecution history in determining how to read claim terms.' [...] because it 'is generated at the time of and for the purpose of litigation and thus can suffer from bias that is not present in intrinsic evidence.' For that reason, 'conclusory, unsupported assertions by experts as to the definition of a claim term are not useful to a court.' Thus 'a court should discount any expert testimony that is clearly at odds with the claim construction mandated by the claims themselves, the written description,and the prosecution history.'" Id. at *13 (internal citations omitted, text added).
Expert Testimony Does Not Trump Instrinsic Evidence"Dr. Salomon’s testimony [...] —that culturing with beads in three-dimensions was known in the art—simply confirms an assumption we already made during our analysis of the intrinsic record. [...] Dr. Salomon’s testimony consists exclusively of three conclusory affirmations elicited by leading questions posed by SkinMedica’s counsel." Id. at *39, 40 (text added). Moreover, while SkinMedica believes Dr. Salomon’s statements are 'perfectly consistent with the intrinsic record,' [...] they are not. The patentees plainly stated in the written description that: 'Cell lines grown as a monolayer or on beads, as opposed to cells grown in three-dimensions, lack the cell-cell and cell-matrix interactions characteristic of whole tissue in vivo.'" Id. at *38 (text added, internal citations omitted).
"Because we find no legal error [...] we affirm the grant of summary judgment [of noninfringement to Histogen]." Skinmedica, at *8 (text added). "Whether viewed as a matter of disclaimer or of lexicography, the result is the same: the kind of three-dimensional culturing protected by the patent excludes use of beads. Because the accused method employs beads, it cannot infringe the patents in suit." Id. at *11. "[A]lthough the inventors never explicitly redefined three-dimensional cultures to exclude the use of beads, their implicit disclaimer of culturing with beads here was even 'so clear that it equates to an explicit one.' [...] [E]ach time the inventors referenced culturing with beads in the specification, they unambiguously distinguished that culture method from culturing in three-dimensions. The patentees repeated and definitive statements clearly indicate that they disclaimed the ordinary meaning of 'culturing . . . cells in three-dimensions.'" Id. at *26 (text added). 


“Rader, Chief Judge, dissenting." Skinmedica, Rader, C.J., Op. at *1.
No Unambiguous and Unmistakable Disavowal of the Ordinary Meaning"Dr. Salomon’s testimony, when viewed as a whole, deserves great weight and respect. [...] [T]he issue [is]: whether or not the patentees’ reference to 'on beads' is in the context of two-dimensional cultures. If so, then Dr. Salomon’s testimony is entirely consistent with the intrinsic patent record." Skinmedica, Rader, C.J., Op. at *4, 6 (text added). "It would not make sense for the patentees to distinguish the medium resulting from cells cultured 'on beads' from that of cells cultured in three-dimensions unless “on beads” is in the context of two-dimensional culturing. [...] It is reasonable to view the 'i.e.' in this case as merely clarifying that the reference to beads is in the context of two-dimensions." Id. Rader, C.J., Op. at *5 (text added). "Because I would find that the patentees did not unmistakably and unambiguously disavow the ordinary meaning of 'culturing . . . cells in three-dimensions' to exclude the use of beads, I would reverse the district court’s grant of summary judgment." Id. Rader, C.J., Op. at *8.


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