District Court Rules That Genencor Products Infringe Novozymes Patent

On July 7, a federal district court in the Western District of Wisconsin ruled on a motion for summary judgment that a number of Genencor's thermostable alpha-amylase products (sold under trade names such as Spezyme) infringe Novozyme’s US patent number 7,713,723. I have discussed earlier decisions in this case on this blog, including decisions by the District Court denying a motion to invalidate the claims for failure to satisfy the written description requirement (available here) and denying a motion for preliminary injunction (available here).

Claim 1 is representative of the claims found to be infringed:

1. An isolated variant of a parent alpha-amylase, wherein:
(a) the variant has at least 90% sequence identity to SEQ ID NO: 6,
(b) the variant comprises a substitution of serine at position 239 relative to the parent alpha-amylase, using the amino acid sequence of SEQ ID NO: 8 for determining position numbering, and
(c) the variant has increased thermostability relative to the parent
alpha-amylase, wherein thermostability is determined at pH 4.5, 90° C. and
5 ppm calcium and has alpha-amylase activity.

Prior to deciding the issue of infringement, the court had to construe several terms appearing in the claims.

For example, the court had to define what "thermostability" means in the context of the claims. The defendant Genencor argued that the term is so indefinite that the claims should be invalidated, but the judge disagreed and held that the term was not so ambiguous as to render the claims invalid. The court spent a lot of time discussing the ambiguity of the term, noting that it could be the case that a protein variant would have more activity than wild type at some time points after exposing the proteins to elevated temperature, but less activity at other time points, and it was not entirely clear from the patent whether this would constitute increased thermostability. However, the court held that even under a relatively narrow interpretation of the term, pursuant to which the protein variant would have to be more active at all time points under elevated temperature, the Genencor products still infringed because the retained higher activity than wild type at all times after exposing the proteins to high temperature.

Another claim term, which the court spent a lot of time was "isolated." Novozymes argued that "isolated" was not a limitation on the claim scope because it is part of the claims’ preamble. The district court spent some time considering this argument, but ultimately sided with Genencor and held that "isolated" does limit the scope of the claim. In part, it reached this decision because "isolated" did not appear in the claim originally but was introduced during prosecution of the patent application, which the court found implied that the term "isolated" was significant.

The parties disputed the meaning of the term “isolated,” with Novozymes arguing for a broad interpretation that would cover protein existing at a higher concentration in a cell or cell extract than it would naturally, while Genencor argued for a narrower interpretation in which the protein must to some extent be separated from other cellular components. The court adopted the narrower interpretation, but nonetheless found that most Genencor products infringed because they included isolated protein. However, the court did find that some Genencor products are not infringing in which the thermostable alpha-amylase is not separated from other cellular components, which the court referred to as "whole broth" products, because the protein is not isolated.

The proper interpretation of "isolated" in claims such as this has important implications for biotechnology patenting outside the confines of this particular case. For example, the patent office will not issue patents claiming naturally occurring gene sequences unless the claims specifically recite that the DNA molecule is isolated, purified, and/or recombinant, in order to exclude genes as they occur naturally (for example in the human genome). The assumption is that inclusion of the term "isolated" in the claim limits the scope of the claim. I don't think it is even accurate to consider the use of the term "isolated" in claims of this format as preamble, but in any event it should generally be treated as limiting the scope of the claim.

Furthermore, the scope of the term isolated is important in the context of gene patent. As I have discussed elsewhere, the question of whether genetic diagnostic testing or whole genome sequencing infringes gene patents could in many cases dependent on how broadly a court interprets the term isolated in these claims (I have always assumed that "isolated" is a meaningful limitation on claim scope in this context).

In this case, the prosecution history was apparently silent as to why Novozymes amended the claim to include the "isolated" language. It would not seem to be necessarily required in this case if the claim only covers non-naturally occurring variants, because then there would be no danger of the claim reading on a naturally occurring biomolecule. But perhaps Novozymes intended for the claim to cover naturally occurring thermostable variants, in which case limiting the claim to isolated variants would be necessary in order for the claim to be valid.

In any event, the fact that "isolated" was introduced by amendment was significant, because it led the court to rule that under Festo the term could not be expanded beyond its literal scope under the doctrine of equivalents.

Thanks to Docket Navigator for bringing this decision to my attention.