By Chris Holman
UCB, Inc. v. Actavis Lab’ys UT, Inc., 2023 WL 2904757, — 4th — (Fed. Cir. Apr. 12, 2023)
Rotigotine is a drug used to treat Parkinson’s disease. People with Parkinson’s disease experience significant gastrointestinal dysfunction, such as difficulty swallowing, which can frustrate the oral administration of drugs. However, the complications associated with oral treatment can be avoided by means of a transdermal patch that delivers the drug through the patient’s skin. In order to cross the skin barrier, however, the drug must be in an “amorphous,” i.e., non-crystalline, form. If the drug crystallizes in the patch, it will generally not be able to cross the skin barrier.
In 2007, UCB invented and marketed “original Neupro,” a transdermal patch for the treatment of Parkinson’s disease containing a dispersion of amorphous rotigotine and polyvinylpyrrolidone (PVP), with the PVP functioning as a stabilizer. Unfortunately, soon after original Neupro entered the market it was found that the rotigotine was crystallizing when stored at room temperature, rendering the drug ineffective. This caused UCB to recall the product from the U.S. market in April 2008 (although it remained in limited use under a compassionate-use program). In Europe, regulators allowed original Neupro to stay on the market, under the condition that it would only be marketed under “cold-chain conditions,” i.e., it would be stored in a refrigerator.
The patent at issue in this case, U.S. Patent No. 10,130,589, is directed towards UCB’s solution to this problem, which was to essentially double the amount of PVP in the patch, from original Neupro’s weight ratio of rotigotine to PVP of 9:2 to the new, reformulated Neupro’s weight ratio of 9:4. In particular the ‘589 patent claims a method for stabilizing rotigotine by combining a non-crystalline form of rotigotine with PVP to form a solid dispersion, wherein the weight ratio of rotigotine to PVP is in a range from about 9:4 to 9:6. UCB re-entered the U. S. market with its reformulated Neupro in 2012.
In 2019, UCB sued Actavis for infringing the ‘589 patent in a Hatch-Waxman lawsuit. The district court found the asserted claims to be invalid based on anticipation and obviousness, particularly in view of earlier-issued UCB patents, i.e., the “Muller patents,” which disclosed combinations of rotigotine and PVP present at a range of weight ratios from 9:1.5 to 9.5. Note that the Muller patents cover both original Neupro (9:2) and reformulated Neupro (9:4), while the ‘589 patent (claiming a range of 9:4 to 9:6) only covers reformulated Neupro. Significantly, UCB had successfully asserted a Muller patent in a previous ANDA suit that resulted in an injunction preventing approval of Actavis’s ANDA until the relevant Muller patent’s expiration in March 2021. The ‘589 patent would not have expired until December 2030, and thus could have delayed FDA approval of a generic version of Neupro by nine additional years.
On appeal, the Federal Circuit reversed the district court’s anticipation ruling, but affirmed on the basis of obviousness. The opinion, authored by Judge Stoll, begins by explaining that Federal Circuit precedent sets forth an established framework for analyzing whether a prior art reference anticipates a claimed range. If the prior art discloses a point within the claimed range, the prior art anticipates the claim. On the other hand, if the prior art discloses an overlapping range, the prior art anticipates the claimed range “only if it describes the claimed range with sufficient specificity such that a reasonable factfinder could conclude there is no reasonable difference in how the inventions operate over the ranges.”
In the case at hand, the prior art Muller patents disclose a range (9:1.5 to 9.5) that overlaps with the range claimed in the ‘589 patent (9:4 to 9:6). The Federal Circuit found that the district court had erred by failing to analyze this as an overlapping range case, but to instead treat this as a case in which the prior art discloses a point within the claimed range. The Muller patents did not literally disclose any point within the range claimed in the ‘589 patent, but the district court had nonetheless concluded, based on expert testimony, that the range disclosed in the Muller patents would implicitly teach a person of skill “a few examples” of specific weight ratios, including 9:4 and 9:5 weight ratios of rotigotine to PVP. Nonetheless, the district court’s error with regard to its anticipation analysis was rendered moot when the Federal Circuit proceeded to affirm its obviousness finding.
Judge Stoll cited Federal Circuit precedent for the proposition that there is a presumption of obviousness when a claimed range overlaps with a range disclosed in the prior art. Although this presumption can be overcome if, e.g., the prior art teaches away from the claimed range, or the claimed range produces new and unexpected results, or other evidence demonstrates the nonobviousness of the claimed range, in this case the Federal Circuit agreed with the district court that UCB had failed to present evidence to rebut the presumption of obviousness.
For example, the district court had not erred in its decision to disregard the commercial success of reformulated Neupro, based on a lack of a nexus between the drug’s commercial success and the claimed invention. In particular, the Federal Circuit agreed that the existence of the Muller patents weakened UCB’s evidence of commercial success, because these patents operated as blocking patents, dissuading competitors from developing a rotigotine transdermal patch, at least until the Muller patents expired. While rejecting UCB’s suggestion that the court’s analysis had branded all co-owned patents as “blocking” patents, the court noted that in this case UCB had held exclusive worldwide rights to rotigotine for all therapeutic indications since 1998, and that until the Muller patents expired Actavis had been enjoined from marketing a generic version of reformulated Neupro.