The Jackson Laboratory, a biomedical research institution and repository for laboratory mice, won a summary judgment of no patent infringement against The Central Institute for Experimental Animals (CIEA). CIEA, a non-profit Japanese corporation that develops animal models used for scientific research, alleged that Jackson had infringed U.S. Pat. No. No. 7,145,055 directed to the creation of transgenic immunodeficient mice by breeding particular progenitor mice, called the NSG mouse.  Central Institute for Experimental Animals v. Jackson Labs, No. C-08-05568.

The ‘055 Patent claims a method of producing an immunodeficient mouse by backcrossing two strains of mice as well as the mouse produced by this method and the use of the mouse. The method claimed in the ‘055 Patent involves backcrossing a NOD/Shi mouse with a C.B.-17-scid mouse to create a NOD/Shi-scid mouse and then backcrossing the NOD/Shi-scid mouse with an interleukin 2 receptor γ chain gene knockout mouse (“IL-2Rγ KO mouse”). Backcrossing is a process of mating two animals so that the offspring have a genetic identity that is closer to the genetic identity of a selected parent.

Claim 1:

1. A mouse produced by a method comprising backcrossing a mouse B with a mouse A, wherein said mouse A is a mouse obtained by backcrossing a C.B-17-scid mouse with an NOD/Shi mouse, and wherein said mouse B is an interleukin 2 receptor .gamma. chain gene knockout mouse, wherein said mouse produced by the method does not express the interleukin 2 receptor .gamma. chain, has an enhanced engraftment capacity of heterologous cells relative to a NOD/shi-scid mouse, has neither functional T-cells nor functional B-cells, exhibits reduced macrophage function relative to a NOD/shi-scid mouse, exhibits no NK cells or NK cell activity, and exhibits reduced dendritic function relative to a NOD/Shi-scid mouse.

Following a claim construction hearing, the court construed the term “NOD/Shi mouse” to mean a non-obese diabetic mouse that:

  1. has not been reproductively separated from the NOD mouse colony created by Dr. Susumu Makino at Shionogi Research Laboratories or
  2. has been reproductively separated from that colony by 20 or fewer generations.

The court construed “NOD/Shi-scid mouse” to mean a mouse strain produced by multiple backcross generations of a C.B.-17 scid mouse with a NOD/Shi mouse.

Jackson’s NSG mouse is created by backcrossing a NOD/LtSz-scid mouse. Because NOD/LtSz-scid mice are produced from NOD/LtSz mice, which have been reproductively separated from Dr. Makino’s NOD mouse colony for over 20 generations, a NOD/LtSz-scid mouse is not a NOD/Shi-scid mouse. Accordingly, CIEA concedes that under the court’s claim construction Jackson’s NSG mouse does not literally infringe the ‘055 Patent. The parties dispute whether Jackson’s NSG mouse infringes the ‘055 Patent under the doctrine of equivalents.

CIEA tried to claim infringement under the doctrine of equivalents based on its contention that use of the NOD/LtSz-scid mouse is equivalent to use of the NOD/Shi-scid mouse in the context of the invention. Jackson argued that CIEA is barred from asserting infringement under this theory because:

  1. the ‘055 Patent discloses but fails to claim use of NOD/LtSz-scid mice, and
  2. adopting CIEA’s position that any substrain of NOD mice are equivalent to the NOD/Shi mice would vitiate the NOD/Shi and NOD/Shi-scid claim limitation in its entirety.

The court found no claim infringement under the doctrine of equivalents based on the disclosure-dedication rule. That is, when a patent discloses but does not claim subject matter, the unclaimed subject matter is dedicated to the public and cannot be recaptured under the doctrine of equivalents. See Johnson & Johnston Assocs., Inc. v. R.E. Serv. Co., Inc., 285 F.3d 1046, 1054 (Fed. Cir. 2002). What is claimed is protected, and “what is not claimed is public property.”

The Federal Circuit considered how specific a disclosure in a written description must be to dedicate matter to the public and held that:

[I]f one of ordinary skill in the art can understand the unclaimed disclosed teaching upon reading the written description, the alternative matter disclosed has been dedicated to the public. This ‘disclosure-dedication’ rule does not mean that any generic reference in a written description necessarily dedicates all members of that particular genus to the public. The disclosure must be of such specificity that one of ordinary skill in the art could identify the subject matter that had been disclosed and not claimed. PSC Computer Prods., Inc. v. Foxconn Int’l, Inc., 335 F.3d 1353, 1360 (Fed. Cir. 2004).

In other words, the relevant test is whether one of ordinary skill in the art reading the patent could identify a specific, unclaimed alternative and understand that it could be used as a substitute for the claimed matter. This test is met when the patent mentions the alternative in a way that would be understood by one of ordinary skill in the art. The disclosure of unclaimed subject matter need not satisfy the written description requirement of 35 U.S.C. § 112.

The court said that the disclosure-dedication rule would preclude CIEA from asserting infringement under the doctrine of equivalents if the ‘055 Patent disclosed use of the NOD/LtSz-scid mouse as an alternative since it did not claim such use of the NOD/LtSz-scid mouse.

Indeed, CIEA contended in its claim construction brief and at the Markman hearing that a person of ordinary skill in the art reading the patent would understand that any NOD-scid mouse, including a NOD/LtSz-scid mouse, could be used to achieve the patent’s stated objective of creating an immunodeficient mouse with engraftment capacity.

As discussed above, the ‘055 Patent clearly disclosed use of the NOD/LtSz-scid mouse in the prior art. Indeed, the ‘055 Patent’s discussion of how the NOD/LtSz-scid mouse had been used in the prior art is far more extensive than the brief mention of plastic parts in the PSC patent. Accordingly, the ‘055 Patent placed the public on notice that NOD/LtSz-scid mice had been used as an alternative to NOD/Shi-scid mice in the prior art, and future use of NOD/LtSz-scid mice would therefore not infringe.

Because the ‘055 Patent discloses but does not claim use of the NOD/LtSz-scid mouse, this unclaimed subject matter is dedicated to the public and cannot be recaptured under the doctrine of equivalents. See Johnson & Johnston, 285 F.3d at 1054. Even if the patentee did not intend to dedicate this subject matter to the public, “[t]he patentee, rather than the public, must bear the burden of inadvertent errors in the patent – including inadvertent dedications.” PSC, 355 F.3d at 1361. Since the disclosure-dedication rule bars CIEA from asserting infringement under the doctrine of equivalents, the court need not reach Jackson’s alternative argument that CIEA’s doctrine of equivalents position would vitiate the NOD/Shi and NOD/Shi-scid claim limitation in its entirety.

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