Claims to a method of hepatocyte cryopreservation are
patent-eligible, according to a recent decision by the U.S. Court
of Appeals for the Federal Circuit.
In Rapid Litig. v. CellzDirect, Inc.1, the
Federal Circuit over-turned the district court's determination
that U.S. Patent No. 7, 604, 929 ("'929 patent")
patent was directed to a patent-ineligible law of nature, namely
that hepatocytes are capable of surviving multiple freeze-thaw
cycles. The Federal Circuit found that while the claims recited a
natural law, they were directed to a new and useful method of
preserving hepatocyte cells.
The '929 patent was based on the inventors' discovery
that some hepatocytes are capable of surviving multiple freeze-thaw
cycles. Previously, it was understood that hepatocytes could only
be thawed once before they would have to be used or discarded. In
view of this discovery, the inventors developed an improved process
of preserving hepatocytes. Accordingly, the '929 patent claims
a method comprising (A) subjecting previously frozen and thawed
cells to density gradient fractionation to separate viable cells
from non-viable ones; (B) recovering the viable cells and (C)
refreezing the viable cells.
The Federal Circuit applied the two-part test set out by the
Supreme Court in Mayo v. Prometheus2 for
determining patent-eligible subject matter under 35 U.S.C. 101. The
Federal Circuit found that the claimed methods could be found
eligible at step one of the test, because they are not simply
directed to patent ineligible subject matter, namely the ability of
hepatocytes to survive multiple freeze-thaw cycles. Rather, the
claims are directed to a new and useful laboratory technique that
produces a "tangible and useful result".
The Federal Circuit distinguished the present claims from those
found ineligible in other recent decisions. For example, in
Ariosa v. Sequenom3 (discussed
here), the patent at issue claimed methods for detecting
paternally inherited cffDNA in the blood or serum of a pregnant
female. According to the Federal Circuit, the existence of cffDNA
is a natural phenomenon and in contrast to the '929 patent,
identifying its presence was merely claiming the natural phenomena
The Federal Circuit further held that even if the '929
patent claims were not found eligible at step one of the
Mayo test, they would be found eligible at step two, as
they recite an improved process for preserving hepatocytes for
future use. In addition, while each of the claims' individual
steps (freezing, thawing, and separating) were known independently
in the art, this does not make the claim unpatentable as it is the
particular combination of steps that is patentable here.
This affirmation of patent-eligible subject matter is welcomed,
as the scope of patentable subject matter in the Life Sciences
continues to be a contentious issue in the U.S. The decision
confirms that applications of natural discoveries are patentable
and that even if a claim recites a natural law, additional claim
elements can provide a new and useful product or method.
1 Rapid Litigation Management Ltd v. CellzDirect Inc.,
15-1570, U.S. Court of Appeals for the Federal Circuit
2 Mayo Collaborative Services v. Prometheus Laboratories,
Inc., 566 U.S. ___ (2012).
3 Ariosa Diagnostics Inc. v. Sequenom Inc., 788 F.3d 1371
(Fed. Cir. 2015).
The content of this article is intended to provide a general
guide to the subject matter. Specialist advice should be sought
about your specific circumstances.
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A recent Saskatchewan Court of Queen's Bench decision allowed a court-appointed receiver to sell and transfer intellectual property rights free and clear of encumbrances, finding that a license to use improvements of an invention was a contractual interest and not a property interest.
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