Polynucleotide Patent Struck Down for Carrying Too Little Information
At the end of last week, the Federal Circuit looked at two patents on labeled polynucleotides, finding that the patents were invalid for insufficient guidance as to how to hybridize the full range of the polynucleotides that they tried to cover. This decision, from the Enzo Life Sciences, Inc. v. Roche Molecular Systems, Inc. case, illustrates the burden on patent applicants to support the entire breadth of the coverage they seek, especially in the realm of biotechnology.
Most of the court’s decision focused on the first of the two patents, which required a non-radioactive label on a phosphate of at least one nucleotide of the polynucleotide. Aside from the non-radioactive requirement, the court found that that patent broadly covered a wide range of labeling, as long as the polynucleotide would remain hybridizable. In particular, the court observed that the patent claims have very little limitation on the location of the labeled nucleotide within the polynucleotide, the type of non-radioactive labeling, the way that the label is bonded to the phosphate group, or the number of labels used.
To be valid, a U.S. patent has to enable someone with ordinary skill in the art to make and use the invention throughout the entire scope covered by the patent, and without undue experimentation. Applying this requirement, the court considered evidence that variations in the location or type of the labeling were understood, at the time when the invention was made, to be potentially disruptive to hybridization, and in an unpredictable way. The patent itself offered little guidance as to how to navigate these factors to produce a polynucleotide that would hybridize successfully.
The court acknowledged that the enablement requirement does not ask for a repetition of things that had been well-known in the field, but maintained for this case that making a hybridizable, labeled polynucleotide had been too unpredictable at the time of the invention. Because the patent failed to meet the requirement to enable the full claimed scope of the invention, the court affirmed a lower court’s decision that the patent was invalid.
Finding the first patent invalid, the court then noted that the second patent was not even limited in requiring the label to be located on the phosphate portion of a nucleotide, and therefore that it too lacked sufficient enablement.
Rulings like this about enablement, along with other Federal Circuit opinions about written description like in the fairly-recent Amgen v. Sanofi case, may set a high bar for patent applicants to support broad or categorical coverage in the life sciences. Patent applicants can therefore benefit greatly from including numerous and varied working examples, whenever possible. Dependent claims drawn to narrower categories or to specific working examples could also save an application or patent from unpatentability or invalidity.