Patent-Eligibility of hESC Challenged

08 July 2013 Personalized Medicine Bulletin Blog

Now that the U.S. Supreme Court has determined that isolated, naturally-occurring genes are not patent-eligible (see, Ass’n. for Molecular Pathology v. Myriad Genetics, Inc., 569 U.S. __ (2013))(“Myriad”), Consumer Watchdog (“CW”, formerly known as The Foundation for Taxpayer and Consumer Rights, a self-described public charity dedicated to provide a voice for taxpayers and consumers) has asked the Federal Circuit to apply the holding of Myriad to in vitro cultured, human embryonic stem cell cultures and deem them patent-ineligible for failing to satisfy 35 U.S.C. § 101. Consumer Watchdog v. Wisconsin Alumni Research Foundation, No. 13-1377 (Fed. Cir. 2013).  

Reexamination of U.S. Patent No. 7,029,913

CW’s challenge is contained in an appeal from a Decision of the USPTO’s Board of Patent Appeals (“Board”) in inter partes reexamination No. 95/000,154, which confirmed the patentability of claims 1-3 of U.S. Patent No. 7,029,913 (the ‘913 Patent) entitled “Primate Embryonic Stem Cells”.  The ‘913 Patent issued on April 18, 2006 naming Dr. James A. Thomson of the University of Wisconsin as the sole inventor. The ‘913 Patent is assigned to Appellee Wisconsin Alumni Research Foundation (“WARF”).

In the reexamination proceeding itself, Appellant CW only challenged the novelty and non-obviousness of the claims. The Board determined that the claims were novel because the cited prior art neither disclosed nor enabled using feeder cells to isolate human embryonic stem cells (“hESCs”). The Board also determined that the evidence of record supported a finding of non-obviousness because one of skill in the art would not have known how to identify and select hESCs during the stem cell derivation process.

After reexamination, claim 1 of the ‘913 Patent, the broadest and only independent claim recites:

1.  A replicating in vitro cell culture of pluripotent human embryonic stem cells derived from a pre-implantation embryo, wherein the stem cells (i) will proliferate in an in vitro culture for over one year in an undifferentiated state without the application of exogenous leukemia inhibitory factor, (ii) maintain a karyotype in which the chromosomes are euploid through prolonged culture, (iii) maintain the potential to differentiate to derivatives of endoderm, mesoderm, and ectoderm tissues throughout the culture, (iv) are inhibited from differentiation when cultured on a fibroblast feeder layer.

Patent-Eligibility of hESCs

CW did not challenge the patent-eligibility of in vitro cultured hESCs in the reexamination proceeding but raises this argument for the first time in this appeal. CW argues that patent-eligibility is a threshold issue to be addressed before subordinate questions such as those related to anticipation and obviousness, citing Alexsam, Inc. v. IDT Corp., 2013 U.S. App. LEXIS 10009, at 30 (Fed. Cir. May 20, 2013)(Mayer, J. dissenting) and U.S. Nat’l Bank v. Indep. Ins. Agents, 508 U.S. 439, 447 (1993). Thus, CW argues that raising the issue of patent-eligibility at this stage is appropriate.

Although the ‘913 Patent expressly recites that the claimed hESCs are an in vitro culture, CW argues that the express limitation of the claims “merely identify properties that are inherent in all ES cells, including those that exist naturally.” CW Brief at page 15.  CW opines that, “if the claimed ES cells were not the same as natural ES cells, the claimed invention would offer very little benefit for medical research.” Id. CW also argues that similar to the facts of Myriad, the ‘913 Patent claims recite neither a method of preparation nor a scientific application of the claimed composition, and that therefore, the claims are directed to a patent-ineligible product of nature.  CW further contends that the ‘913 Patent claims do not distinguish the claimed hESCs from those that exist in nature and that the patentee “did not create or alter the properties inherent in stem cells any more than Myriad created or altered the genetic information encoded in the DNA it claimed.” Id.

Anticipation and Obviousness

CW also challenges the Board’s determination that the ‘913 Patent claims at issue were novel under 35 U.S.C. § 102. In the proceeding below, the Board held that the cited prior art (U.S. Patent No. 5,166,065, issued November 24, 1992 “Williams”) did not teach the use of feeder cells to isolate embryonic stem cells. CW disagreed with the Board’s interpretation that Williams only taught the use of feeder cells to maintain ES cells, but not to derive them.  

CW also argues that no innovation was required to isolate the hESCs and that therefore, the claims are invalid for failing to satisfy 35 U.S.C. § 103 (non-obviousness). In arguing obviousness of the claims, CW challenges the expert opinion of Dr. Steward who declared that the morphology of hESCs are different from prior art mouse ES cell colonies. In the reexamination proceeding, Dr. Stewart had submitted a declaration noting that hESCs colonies are flatter and more compact than mouse ES cell colonies and that therefore, colonies of hESCs had not been described before the invention of the ‘913 Patent. CW urges the Federal Circuit not to rely on the testimony of Dr. Stewart but rather to rely on the teachings of other cited prior art that describes the isolation of mouse embryonic stem cells to guide the ordinary skilled scientist to test different colony types for features common to embryonic stem cells.

CW also urges the Federal Circuit to disregard secondary evidence of non-obviousness presented in the reexamination proceeding. In particular, CW asks the Federal Circuit to disregard evidence that others in the field had followed inventor Thomson’s work to isolate hESCs and to disregard the acclaim Dr. Thomson has received in the field for his patented invention.

Cultured hESCs -  Nonnatural Composition of Matter?

In its recent Myriad decision, the US Supreme Court held that isolated, naturally-occurring genes are not patent-eligible under 35 U.S.C. § 101 because isolated genes are a product of nature. The Myriad Court distinguished the facts and holding from a prior Supreme Court’s decision, Diamond v. Chakrabarty, 447 U.S. 303, 309 (1980). In Chakrabarty, the Supreme Court had previously held that genetically modified bacterium was patent-eligible. The Myriad Court distinguished the claimed isolated, natural-occurring genes from the subject of the Chakrabarty case, wherein the Court had held that the inventors had created a patentable, new composition of matter when they added four plasmids to a bacte­rium, which enabled it to break down various components of crude oil.  Myriad, Slip Op. at 12, citing Chakrabarty, 447 U. S. at 305, and n. 1. The Myriad Court explained that the claimed genetically modified bacterium was “not to a hitherto unknown natural phenomenon, but to a nonnaturally occurring manufacture or composition of matter—a product of hu­man ingenuity ‘having a distinctive name, character [and] use.’” Id., citing Chakrabarty, at 309–310. The Chakrabarty bacterium was new “with markedly different characteristics from any found in nature,” 447 U. S., at 310, due to the additional plasmids and resultant “capacity for degrading oil.” Id., citing Chakrabarty, at 305, n. 1. The Court in Myriad held that in contrast, “Myriad did not create anything. To be sure, it found an important and useful gene, but separating that gene from its surrounding genetic material is not an act of invention.” Myriad, Slip Op. at 12. The Court in Myriad also determined, however, that unlike isolated, naturally-occurring genes, man-made cDNA was patent-eligible because “the lab technician unquestionably creates something new when cDNA is made.” Myriad, Slip Op. at 17.

Thus, the question for the Federal Circuit in this case is whether the claimed, cultured hESCs are markedly different from naturally-occurring hESCs. Does the process of culturing the cells provide the cells with “with markedly different characteristics from any found in nature?” Or, put differently, are hESCs more like patent-eligible man-made genes or more like patent-ineligible isolated, naturally-occurring genes?

Many in the biotech community were relieved that the Supreme Court in Myriad limited its holding of patent-ineligibility to isolated, naturally-occurring genes.  However, patent practitioners cautioned that Myriad’s holding could potentially be applied to other isolated, naturally-occurring products, including stem cells. The WARF case is likely the first test case before the Federal Circuit, and perhaps the U.S. Supreme Court ultimately, to define the reach and impact of Myriad beyond gene patents.

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