Claimed Ranges Overlapping the Prior Art Can Lead To Short Patent Shelf-Life

| Matthew S. WhiteheadDouglas B. Wentzel


Before Moore, Chen, and Stoll. Appeal from the U.S. District Court for the District of Delaware.

Summary: District court legally erred by applying incorrect anticipation framework but correctly found that patent claiming a ratio range was obvious over prior art disclosing overlapping range.

UCB sued Actavis for patent infringement after Actavis submitted an Abbreviated New Drug Application (ANDA) directed toward UCB’s drug Neupro®. The asserted patent was directed to a new version of Neupro® that provided longer shelf-stability at room temperature than the original Neupro® formula, which was the subject of UCB’s earlier-but-unrelated “Muller” patents. Specifically, the asserted patent improved upon the original Neupro® formula by increasing the ratio of rotigotine to polyvinylpyrrolidone (PVP). However, the range of rotigotine-to-PVP ratios claimed in the asserted patent overlapped with the range of ratios disclosed in the Muller patents. The district court found that the asserted claims were both anticipated and obvious in view of the range of ratios disclosed by the Muller patents. UCB appealed both findings.

Regarding anticipation, the Federal Circuit found legal error in the district court’s analysis. The Muller patents undisputedly disclosed a range of ratios overlapping with the claimed range. Thus, the Federal Circuit explained that the district court should have applied the traditional framework for analyzing overlapping ranges, which requires assessing whether the claimed range is critical to the operability of the claimed invention. Because the district court’s analysis relied on the “immediately envisage” line of cases instead of the traditional framework for overlapping ranges, the Federal Circuit found legal error.

Regarding obviousness, the Federal Circuit affirmed the district court’s findings. The Federal Circuit agreed a presumption of obviousness applied because the Muller patents disclosed ranges of ratios overlapping with the claimed range. The Court also agreed that the Muller patents were usable prior art because they reflected the state of the art at the time of the asserted patent. The Federal Circuit further agreed that another reference did not teach away because it did not criticize, discredit, or otherwise dissuade a skilled artisan from investigating the claimed range of ratios.

The Federal Circuit also affirmed the district court’s findings of no unexpected results and weak evidence of commercial success. The Federal Circuit agreed that the finding of no unexpected results was supported by evidence that a skilled artisan would expect the claimed ratio range and the prior art’s range to provide drug stability in a similar way. The Court also emphasized that any differences in stability between the claimed range the prior art range was one of degree (e.g., more stability), which was less persuasive than a difference in kind (e.g., a new property). The Federal Circuit also agreed there was weak evidence of commercial success because the prior art Muller patents operated as blocking patents that dissuaded competitors from developing the drug formulation claimed in the asserted patent.

Editor: Paul Stewart