As reported in our February 1, 2017 post, patent owners have had a difficult time convincing the PTAB that secondary considerations are sufficient to overcome a prima facie case of obviousness. The Crown Packaging decision, highlighted in that post, provides a roadmap for patent owners to follow when relying on secondary considerations to save their patent claims. More recently, however, the Federal Circuit affirmed yet another PTAB decision finding insufficient a patent owner’s evidence of secondary considerations. In re: Depomed, Appeal No. 2016-1378 (Feb. 21, 2017) (non-precedential).
At issue was Depomed’s U.S. Patent No. 6,723,340 (“the ’340 patent”). The ’340 patent discloses that many drugs have their greatest therapeutic effect when they are released in the stomach in a prolonged, continuous manner because such delivery presents fewer side effects and reduces the need for repeated or frequent dosing. One way of obtaining prolonged release is gastric retention, which uses drug formulation particles small enough to be swallowed comfortably but that swell to a larger size upon contact with gastric fluids. An example of gastric retention is dispersing the drug in a solid matrix that absorbs the gastric fluid and swells as a result of the absorbed fluid. These polymer matrices provide a controlled release of the drug. Two examples of matrix materials used in the art are poly(ethylene oxide) (“PEO”) and hydroxypropyl methylcellulose (“HPMC”). Both PEO and HPMC have drawbacks when used as swelling matrices. The ’340 patent aims to improve on these drawbacks by combining PEO and HPMC in a matrix.
In the Final Written Decision, the Board found that claims 1, 3-5, and 11-13 were unpatentable as obvious in view of PCT Application No. WO 98/55107 (“Shell 1998”). The Board also found that claims 1, 3-5, and 10-13 were unpatentable as obvious in view of Shell 1998 in combination with U.S. Patent No. 4,871,548 (“Papadimitriou”).
During the IPR, Depomed argued that the challenged claims were not obvious because the inventors discovered that the combination of PEO and HPMC provided better controlled-release properties compared to using PEO or HPMC alone. Specifically, Depomed pointed to column 3 of the specification, which states that combining HPMC and PEO provides “unexpectedly beneficial performance, avoiding or substantially reducing the problems” with using either HPMC or PEO alone. Col. 3, ll. 33-40. In response, the Board found that Depomed’s evidence was entitled to “little weight” and was insufficient to overcome the petitioner’s obviousness showing.
The Board found that a POSA, upon reading the prior art, would have expected the combination of PEO and HPMC to exhibit controlled-release properties. In particular, the Board noted that Shell 1998 discloses (1) a finite number of matrix polymers; (2) the matrix polymers can be used alone or in combination; (3) that “[c]ertain combinations will often provide a more controlled release of the drug than their components when used individually.” It was this latter point on which the Board relied to reject Depomed’s assertion of unexpected results.
Depomed also argued to the Board that the obviousness analysis improperly relied on hindsight because there was no motivation to combine PEO and HPMC. Finally, Depomed argued that the Board erroneously required evidence of a failure of others to establish a long-felt but unmet need. The Board rejected all of Depomed’s arguments and held the claims unpatentable.
The Federal Circuit affirmed the Board’s decision, noting that substantial evidence supported the Board’s findings and its ultimate conclusion of obviousness. The Court explained that failure of others and long-felt but unmet need were separate and distinct secondary considerations, and clarified that a patent owner can rely on evidence of long-felt but unmet need without providing evidence of a failure of others. Ultimately, the Court rejected Depomed’s evidence of long-felt but unmet need.
Interestingly, Judge Reyna concurred in the result, but found two problems with the Board’s decision. First, he felt that that the Board improperly employed a two-step approach in its obviousness analysis because the Board first made initial conclusions of obviousness and only later considered Depomed’s evidence of secondary considerations. Judge Reyna pointed out that the Board included its prima facie obviousness and secondary considerations analyses in separate sections of the decision. In his view, this was evidence that the Board used a two-step approach, which is improper under the Court’s precedent.
Second, Judge Reyna criticized the Board’s decision to assign “little weight” to Depomed’s evidence of secondary considerations. According to Judge Reyna, the Court’s case law “does not ask whether results are ‘really unexpected’ or just a ‘little unexpected.’” Therefore, it is improper to assign a particular weight to the evidence. As Judge Reyna saw it, the Board’s assigning weight to the evidence demonstrated that its analysis was incorrect and that the Board improperly shifted the burden to patent owner. Ultimately, however, Judge Reyna did not propose remand to the Board because even under a proper analysis, Depomed’s evidence of secondary considerations did not compel a conclusion of non-obviousness in view of Shell 1998 and Papadimitriou.
The Federal Circuit’s Depomed decision, including Judge Reyna’s concurrence, provides additional guidance to practitioners regarding the treatment of secondary considerations in IPR proceedings.
Latest posts by David Maiorana (see all)
- PTAB Applies General Plastic Factors to Serial Petitions Seeking Joinder - September 15, 2023
- PTAB Clarifies Claim Preclusion Standards - July 20, 2023
- Director Determines Petitioner Not Expected to Anticipate § 325(d) Argument - May 1, 2023