Supernus Pharms., Inc. v. Actavis Inc.

Based on the court’s claim construction, two of the three patents-in-suit were found infringed, and all three were not invalid.

April 07, 2016

GENERICally Speaking

Case Name: Supernus Pharms., Inc. v. Actavis Inc., Civil Nos. 13-4740 (RMB/JS), 14-1981 (RMB/JS), 2016 U.S. Dist. LEXIS 14111 (D.N.J. Feb 5, 2016) (Bumb, J.)

Drug Product and Patent(s)-in-Suit: Oxtellar XR® (oxcarbazepine); U.S. Patents Nos. 7,722,898 (“the ’898 patent”), 7,910,131 (“the ’131 patent”), and 8,617,600 (“the ’600 patent”)

Nature of the Case and Issue(s) Presented: Supernus makes and sells Oxtellar XR, a once-daily extended-release tablet of oxcarbazepine used to treat seizures in epilepsy patients. Actavis submitted an ANDA seeking to market a generic oxcarbazepine. Supernus sued, claiming that Actavis’s ANDA product would infringe the three patents-in-suit. Actavis countered with arguments of non-infringement and invalidity. The court found that the ’898 and ’131 patents were valid and infringed, and that the ’600 patent, while valid, was not infringed.

Why Supernus Prevailed:  The court construed “homogeneous matrix” to mean “a matrix in which the ingredients or constituents are uniformly distributed”; “Cmin”was the “minimum concentration in blood or plasma at steady state”; and “Cmax” was the “maximum concentration in blood or plasma at steady state.” Based on those constructions, the court made it clear that (i) the terms “blood” and “plasma” should be used interchangeably, as they were in the specification; and (ii) Cmax had to be measured at steady state conditions.

Applying those constructions, the Court found that Actavis infringed the asserted claims of the ’898 and ’131 patents. Actavis argued that its ANDA product did not include a “homogeneous matrix,” as required by the asserted claims. Actavis’s manufacturing process, and that fact that its tablets passed the FDA’s uniformity testing, indicated the presence of a homogeneous matrix. Finally, Supernus’s expert was able to chemically image Actavis’s tablets using Raman imaging and spectroscopy. His results showed the homogeneity of the tablet. The dependent claims, requiring specific Cmin and Cmax values, were also proven to be infringed through superposition analysis and extrapolation.

In contrast, the ’600 patent required multiple elements present at specific weight ranges in the formulation of the tablet. The court found that Actavis’s tablet was missing two such elements. The first missing element was 1-80% by weight of an agent that enhances the solubility of oxcarbazepine that is also a surface active agent, a complexing agent, a cyclodextrin, pH modifying agent, or a hydration promoting agent. Instead, Actavis’s tablet contained another, confidential solubility enhancing agent that did not fall into any of these categories. Similarly, the ’600 patent also required the presence of 10-90% by weight of at least one release promoting agent selected from a predefined group of agents. The Actavis tablets used a different release promoting agent, and thus did not infringe the ’600 patent.

Actavis also argued that the asserted patents were invalid because they were obvious, not adequately described, and indefinite. The court disagreed on all three points. Firstly, the patents-in-suit were not obvious because they contemplated a different, once-daily, extended release, dosing frequency compared to the immediate-release formulations taught in the prior art. Further, the patents-in-suit taught a different active ingredient from what was taught in the prior art. Actavis attempted to analogize oxcarbazepine to another, similar formulation, carbamazepine. The prior art, however, treated the two chemical formulations as distinct therapeutic agents and, indeed, taught away from using oxcarbazepine in place of carbamazepine. Finally, the secondary considerations of non-obviousness bolstered the patents-in-suit—Oxtellar XR® fulfilled a long-felt need, the industry was skeptical of oxcarbazepine’s ability to be used for a once-daily tablet, and other inventors had failed to create such a once-daily tablet. The remaining factors were neutral. Thus, the patents-in-suit were not obvious.

Turning to the Section 112 arguments, Actavis argued that the patents did not demonstrate that Supernus was in possession of a “homogeneous matrix” as described in the specification. Each patent, however, explicitly disclosed a step-by-step process for manufacturing a homogeneous matrix tablet. Actavis’s indefiniteness challenges were similarly dismissed. Actavis argued that the patents-in-suit provided no guidance as to determining whether a matrix was indeed homogeneous. The court found that a person of ordinary skill would have no trouble understanding that a homogeneous mixture was a mixture of two or more ingredients uniformly dispersed in a pharmaceutical formulation. In addition, one of ordinary skill would also know that perfect homogeneity was not achievable.

Back to Top