In Purdue Pharma L.P., v. Collegium Pharmaceutical, Inc., [2022-1482] (November 21, 2023), the Federal Circuit affirmed the Final Written Decision of the PTAB that claims 1–17 of U.S. Patent No. 9,693,961 were unpatentable for lack of written description and anticipation.  The patent is titled “Pharmaceutical Formulation Containing Gelling Agent” and is meant to prevent or deter the abuse of opioid analgesics by the inclusion of at least one aversive agent.

Deadline for Final Written Decision

At the outset, the Federal Circuit rejected Purdue’s argument that the Board lacked authority to issue a Final Written Decision once the deadline established by 35 U.S.C. § 326(a)(11) and 37 C.F.R. § 42.200(c) (one year plus the six-month extension) passed.

Written Description

On written description, the test for sufficiency is whether the disclosure of the application relied upon reasonably conveys to those skilled in the art that the inventor had possession of the claimed subject matter as of the filing date.  The Federal Circuit said it has required that the specification provide sufficient blaze marks to “guide a reader through the forest of disclosed possibilities toward the claimed compound.”  The issue was whether the ’961 specification adequately disclosed the claimed polyglycolyzed glycerides (“PGGs”) as an aversive agent. The Board found the claimed formulation was not disclosed, and the Federal Circuit concluded that substantial evidence supported the Board’s finding.

Although the ’961 claims on their face do not require an aversive agent, the specification makes clear that the claims require “inclusion of at least one aversive agent” and the parties agree that the claims require the use of an aversive agent.  PGGs are identified as a possible surfactant “useful in accordance with the present invention.”  While the specification discloses that some surfactants can be gelling agents and that gelling agents can satisfy the aversive agent requirement, the parties agree that not all surfactants are gelling agents.  The specification does not say that PGGs are gelling agents.  The only time PGGs are mentioned in the specification, they are described as a surfactant, and not as a gelling agent, and surfactants generally are described as “useful in accordance with the present invention.”  In other parts of the specification, the patent recognizes that surfactants can be used completely separate from and in addition to the gelling agent.

The Federal Circuit said that “[j]ust because the specification states PGGs are useful for the invention does not suggest how PGGs are gelling agents. The disclosure of the application does not reasonably convey to those skilled in the art that the inventor had possession of the claimed drug formula containing PGGs as a gelling agent (aversive agent). In other words, there are insufficient blaze marks.” Because the anticipation finding flowed from the lack of written description in the claimed priority application, the finding of anticipation was affirmed.