Amneal Pharms., LLC v. Supernus Pharms., Inc.

In three separate but related final written decisions in the first successful defense of a pharmaceutical patent in an inter partes review (IPR), the U.S. Patent and Trademark Office’s (PTO) Patent Trial and Appeal Board (PTAB or Board) found that the petitioner had failed to prove by a preponderance of the evidence that the challenged claims were unpatentable for obviousness. Amneal Pharms., LLC v. Supernus Pharms., Inc., Case Nos. IPR2013-00372, -00368, and -00371 (PTAB, Dec. 9, 2014) (Kamholz, APJ).

The petitioner challenged the patentability of several claims found in three separate, but related, patents. The three patents relate generally to pharmaceutical formulations that may be used to inhibit the activity of collagen destruction enzymes that are associated with human diseases, such as rosacea, without producing the undesired side effects of competing treatments.

The only claim term requiring construction was “delayed release.” Neither the patent owner nor the petitioner proposed a specific construction of the term in their briefs, nor did the patents at issue provide an express definition. Ultimately, the parties agreed that “delayed release” was correctly defined as the “release of a drug at a time other than immediately following oral administration.” However, the parties disagreed as to whether the broadest reasonable construction of the term further required that there be “no substantial release in the stomach.”

The patent owner argued that the delayed release formulations described in the challenged patents did not allow for “substantial release” in the stomach. As supporting evidence, the patent owner cited to language in the patents that stated “[w]ith the enteric coated pellets, there is no substantial release . . . in the acidic stomach environment.” The petitioner countered that “delayed release” should be broadly construed so as to include drug release “after only a time lag and without respect to whether release occurs in the stomach.”

The PTAB agreed with the petitioner, finding that the broadest reasonable construction of “delayed release” was not limited to only those formulations requiring that there be no substantial release in the stomach. In its reasoning, the PTAB noted that the patents disclosed formulas other than the enteric coated pellets cited by the patent owner and explained that the PTAB “will not read the limitations of an embodiment, even a preferred embodiment, into the construction of a claim term that is plainly used elsewhere in the specification more broadly.”

The PTAB further buttressed its reasoning by looking at extrinsic evidence of how the term is understood and used by persons of ordinary skill in the art. This evidence demonstrated that the term “delayed release” is almost uniformly used in reference to formulations that “allow for release of a drug only after some delay following oral administration.”

With claim construction complete, the PTAB turned to the issue of whether the claims at issue were unpatentable for obviousness over the prior art. The petitioner argued that it would have been obvious to a person of ordinary skill in the art that the prior art disclosed delayed release formulations. The patent owner countered by arguing that the prior art did not disclose a delayed release, but rather a “modified sustained release” that begins slowly but promptly within the stomach following oral administration.

The PTAB found the patent owner’s argument compelling, agreeing with expert testimony stating that “dissolution, however rapid, necessarily requires some finite amount of time to allow interaction of the solvent and the solute.” Further, the PTAB noted that the petitioner’s expert’s conclusions were premised on the “unwarranted” assumption that the prior art disclosed a delayed release formulation. The PTAB thus found that the petitioner had failed to meet its burden, that the challenged claims were not unpatentable.