Previous posts, e.g., here and here, discussed the patent infringement litigation between Danish biopharm rivals Novozymes and Danisco (now owned by DuPont), which are both active in developing enzymes used in the production of biofuels.
In the suit, Novozymes accused Danisco of infringing U.S. Patent No. 7,713,723 (’723 Patent) by selling alpha amylase enzymes including Danisco’s GC358 product (see the complaint here: novozymes_complaint.pdf).
The ’723 Patent, which claims priority back to an application filed in 2000, is entitled “Alpha amylase mutants with altered properties” and relates to variants of certain alpha amylases that exhibit altered stability under high temperatures, low pH and other conditions. The patented variants can be used for starch conversion in ethanol production.
The case has seen some legal twists and turns. In February 2011, the’ 723 Patent survived a close shave on Danisco’s summary judgment motion of invalidity based on a written description argument. Then, in November 2011, the jury found that Danisco infringed the ’723 Patent and awarded Novozymes over $18 million in damages.
There was a dramatic turnaround when Danisco’s post-trial motion succeeded in persuading the trial court judge that the jury verdict should be vacated and the patent declared invalid for failure to satisfy the written description requirement.
A U.S. patent must have an adequate written description to be valid. This means the patent’s specification (which includes the written description and figures) must convey to a person skilled in the relevant technical field that the inventor actually invented and “had possession” of the claimed invention.
Danisco argued that the ’723 Patent – directed to a substitution of an amino acid at position 239 in the alpha-amylase protein – was inadequate because the written description lists position 239 as one of 33 possible positions for an “alteration” and lists a substitution as just one possible type of alteration. The trial court agreed and invalidated the patent.
Novozymes appealed this final decision, and recently the U.S. Court of Appeals for the Federal Circuit affirmed that the ’723 Patent is invalid, in all likelihood ending the case.
The Federal Circuit found that the written description of the original ’723 Patent does provide “formal textual support” for the claimed enzymes, but it fails to describe the “actual functioning, thermostable alpha-amylase variants” recited in the claims. There were too many possibilities, the court said, and no instruction on how to narrow them:
[O]ne searces the 2000 application in vain for the disclosure of even a single species that falls within the claims or for any “blaze marks” that would lead an ordinarily skilled investigator toward such a species among a slew of competing possibilities.
While the 2000 application does specifically describe a substitution at position 239 (S239W), that particular substitution does not confer increased thermostability in alpha-amylase enzymes as claimed in the ’723 Patent, and there is no indication that “Novozymes had invented any thermostable alpha-amylase variants substituted at amino acid position 239 by the time of filing.”
To do so, the court stated, Novozymes would have had to actually make and test individual variants or at least identify subclasses of variants that would be expected to possess the claimed properties. The 2000 application does not go nearly far enough in this regard:
At best, the 2000 application describes a roadmap for producing candidate alpha-amylase variants and then determining which might exhibit enhanced thermostability.
Accordingly, the Federal Circuit affirmed the district court’s judgment of invalidity for insufficient written description:
We hold that no reasonable jury could find that the claims of the ’723 patent meet the written description requirement…and that the district court therefore correctly entered judgment as a matter of law invalidating those claims. In contrast to the claims – which narrowly recite specific alpha-amylase variants that result from mutating a particular parent enzyme at a single amino acid position to yield distinctive functional properties – the supporting disclosure of the 2000 application provides only generalized guidance listing several variables that might, in some combination lead to a useful result. Taking the claims as a whole rather than as the sum of their individual limitations, nothing in the 2000 application indicates that Novozymes then possessed what it now claims.
This case highlights a common patent prosecution practice used by technology firms to compete with their close rivals, that is, keeping an old patent application alive to preserve the early priority date and drafting claims to ensnare a competitor’s new product.
As mentioned above, the ’723 Patent traces priority back to an application filed in 2000. It was only upon learning that DuPont had introduced a thermostable BSG alpha-amylase variant substituted at position 239 that Novozymes filed a new continuation application in December 2009 with claims directed to variants substituted at position 239.
There would be nothing wrong with that if the newly claimed subject matter had been fully disclosed in the original 2000 application. However, the courts found that was not the case here. In its decision on post-trial motions, the trial court noted that a patentee cannot later flesh out the invention:
The concern is that a patentee may attempt to use later filed claims, relying on more recently discovered data, to expand the scope of his invention or to complete an idea.
Eric Lane is a patent attorney at McKenna Long & Aldridge LLP in San Diego and the author of Green Patent Blog. Mr. Lane can be reached at email@example.com