1. A method of producing a desired preparation of multi-cryopreserved hepatocytes, said hepatocytes being capable of being frozen and thawed at least two times, and in which greater than 70% of the hepatocytes of said preparation are viable after the final thaw, said method comprising:
(a) subjecting hepatocytes that have been frozen and thawed to density gradient fractionation to separate viable hepatocytes from nonviable hepatocytes,
(b) recovering the separated viable hepatocytes, and
(c) cryopreserving the recovered viable hepatocytes to thereby form said desired preparation of hepatocytes without requiring a density gradient step after thawing the hepatocytes for the second time, wherein the hepatocytes are not plated between the first and second cryopreservations, and wherein greater than 70% of the hepatocytes of said preparation are viable after the final thaw.
5. The method of claim 1, wherein said preparation comprises a pooled preparation of hepatocytes of multiple sources.
Appeal from United States District Court for the Northern District of Illinois. The district court found that claims were directed to a patent-ineligible law of nature and that the claims lacked the requisite inventive concept. Based on that finding, the district court granted defendant’s motion for summary judgment.
Exception Category: Law of Nature
“The district court had identified in the claims what it called a ‘natural law’—the cells’ capability of surviving multiple freeze-thaw cycles.”
Here, the Federal Circuit disagreed, stating that “the claims are not [simply] directed to the ability of hepatocytes to survive multiple freeze-thaw cycles. Rather, the claims of the ‘929 patent are directed to a new and useful laboratory technique for preserving hepatocytes. This type of constructive process, carried out by an artisan to achieve ‘a new and useful end,’ is precisely the type of claim that is eligible for patenting.”
“The claims in this case are immediately distinguishable from those we have found patent ineligible in cases since Mayo and Alice.
In recent cases, we found claims ‘directed to’ a patent-ineligible concept when they amounted to nothing more than observing or identifying the ineligible concept itself.”
“The end result of the ’929 patent claims is not simply an observation or detection of the ability of hepatocytes to survive multiple freeze-thaw cycles. Rather, the claims are directed to a new and useful method of preserving hepatocyte cells.”
“[T]he claims are directed to a new and useful process of creating [a] pool [of multi-cryopreserved hepatocytes], not to the pool itself.”
“As the Supreme Court has made clear, ‘an invention is not rendered ineligible for patent simply because it involves’ one of the patent-ineligible concepts.”
“At step one, therefore, it is not enough to merely identify a patent-ineligible concept underlying the claim; we must determine whether that patent-ineligible concept is what the claim is ‘directed to.’”
Significantly More: Yes
The claims “recite an improved process for preserving hepatocytes for later use. The benefits of the improved process over the prior art methods are significant. The claimed method is used to create hepatocyte preparations that no longer exhibit unacceptable loss of viability. And it allows researchers to pool samples together in advance and preserve them for later use, rather than needing to wait until enough single samples are accumulated that can be pooled and used immediately. The claimed method is patent eligible because it applies the discovery that hepatocytes can be twice frozen to achieve a new and useful preservation process.”
A particular “combination of steps” can lead to valid patent claims that depend upon a natural relationship. “Just as in Diehr, it is the particular ‘combination of steps’ that is patentable here.”
“This is true even though the individual steps may have been well known.”
“To require something more … would be to discount the human ingenuity that comes from applying a natural discovery in a way that achieves a ‘new and useful end.’”