PTAB

PGR2018-00048

Collegium Pharmaceutical Inc v. Purdue Pharma LP

Key Events

Petition

petition

Title: Pharmaceutical Formulation Containing Gelling Agent
Brief Description: The ’961 patent relates to oral opioid analgesic dosage forms designed to be abuse-deterrent. The claimed invention is a method of preparing a controlled-release dosage form containing oxycodone, polyglycolyzed glycerides, fatty acids, carnauba wax, and beeswax, which is asserted to be abuse-deterrent when subjected to tampering by heating.

Prior Art Relied Upon: Not applicable (challenge is based on the patent’s own specification and priority documents).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner argued that the ’961 patent and its priority applications fail to provide adequate written description for the full scope of the challenged claims for two main reasons. First, the specification exclusively described and enabled abuse deterrence through the use of "aversive agents" (e.g., bittering, irritant, or gelling agents), but the challenged claims broadly recite an "abuse deterrent dosage form," which encompasses other known but undisclosed mechanisms (e.g., dyes, emetics, precipitants). Second, the specification did not describe the claimed combination of ingredients (oxycodone, polyglycolyzed glycerides, fatty acid, carnauba wax, and beeswax) together in a single embodiment. Petitioner contended this constituted impermissible "picking and choosing" from disparate lists of potential ingredients, meaning the inventors were not in possession of the specific claimed formulation.

Prior Art Relied Upon: Not applicable (challenge is based on the patent’s own specification and the state of the art).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner argued that the specification did not enable a person of ordinary skill in the art (POSA) to practice the claimed invention without undue experimentation. The core of this argument was that pharmaceutical formulation is an inherently unpredictable art. The ’961 patent’s specification provided no working examples of the claimed formulation, no guidance on the specific grades or ratios of the broadly claimed ingredients, and no direction on how to achieve the functional limitations of 12-hour controlled release and abuse deterrence upon heating. Petitioner asserted that the vast number of possible combinations of ingredients (estimated at over one million) would require a POSA to engage in a prolonged and undue trial-and-error research project, rather than routine experimentation.

Prior Art Relied Upon: Not applicable.
Core Argument for this Ground:
- Prior Art Mapping: Petitioner argued the claims were indefinite because they recited a desired result—an "abuse deterrent dosage form"—without reciting the specific process or materials sufficient to produce that result. The claims defined the invention by its function rather than its structure. Petitioner contended that this functional claiming left a POSA unable to determine with reasonable certainty whether a given formulation fell within the scope of the claims, as the specification failed to provide a clear standard or method for measuring or determining the "abuse deterrent" property as claimed.

Prior Art Relied Upon: Rariy (Application # 2011/0142943).
Core Argument for this Ground:
- Prior Art Mapping: Petitioner argued that Rariy, an application assigned to Collegium, disclosed every element of the challenged claims. Rariy described tamper-resistant pharmaceutical compositions containing an opioid (e.g., oxycodone), waxes (beeswax, carnauba wax), and lipophilic compounds (fatty acids like myristic acid) to create a controlled-release formulation. Petitioner mapped each claimed ingredient to disclosures in Rariy. The key functional limitation—being abuse-deterrent upon heating above 45° C—was argued to be an inherent property of the formulation disclosed in Rariy. Petitioner supported this by citing its own internal testing of an identical formulation (DETERx), which demonstrated resistance to syringing after being heated, thus proving the inherent abuse-deterrent characteristic.

The Petitioner’s arguments relied heavily on the construction of the term "abuse deterrent dosage form."
Petitioner proposed that this term should be construed broadly as "a dosage form that is subject to less parenteral, intranasal, or oral abuse than other dosage forms," based on language in the specification. This construction supported the written description argument by highlighting that the specification only described a narrow subset (formulations with "aversive agents") of what the term broadly covers, while the claims attempted to capture the entire genus.

The petition argued that the challenged claims of the ’961 patent were eligible for Post-Grant Review (PGR), even though the patent claimed priority to a chain of pre-AIA applications.
Petitioner contended that the ’961 patent was not entitled to the earlier priority dates because the priority applications failed to provide adequate written description and enablement support under §112 for the challenged claims. As a result, the claims' effective filing date was the actual filing date of the application leading to the ’961 patent (February 4, 2016), which is post-AIA, making the patent properly subject to PGR.

Petitioner requested institution of a Post-Grant Review (PGR) for each ground presented and a final determination that claims 1-17 of the ’961 patent are unpatentable and should be canceled.