By Donald Zuhn --
Last month, in In re Depomed, Inc., the Federal Circuit affirmed the determination by the U.S. Patent and Trademark Office Patent Trial and Appeal Board that two instituted grounds in an inter partes review rendered claims 1, 3-5, and 10-13 of Depomed's U.S. Patent No. 6,723,340 unpatentable as obvious.
The '340 patent relates to vehicles for drug delivery, and more particularly to a controlled-release tablet comprising a solid monolithic matrix that comprises a combination of poly(ethylene oxide) and hydroxypropyl methylcellulose. The claimed controlled-release tablet provides gastric retention, wherein the drug being delivered is retained in the stomach for a prolonged duration, by using matrix material that provides drug formulation particles that are small enough to be swallowed comfortably, but that swell to a larger size upon contact with gastric fluids. In the case of the claimed controlled-release tablet, the poly(ethylene oxide) ("PEO") and hydroxypropyl methylcellulose ("HPMC") are both matrix materials that possess swelling and controlled release properties. According to the '340 patent specification, combining PEO and HPMC yields "a swellable, sustained-release tablet [that] provides unexpectedly beneficial performance, avoiding or substantially reducing the problems [with using either matrix material alone] and offering improved control and reliability while retaining both the ability to swell for gastric retention and to control release."
Endo Pharmaceuticals, Inc. filed a petition for inter partes review of the '340 patent alleging that claims 1-5 and 10-13 were unpatentable as obvious under 35 U.S.C. § 103 on five prior art grounds, and the Board instituted an IPR on claims 1, 3-5, and 10-13 on three obviousness grounds: (1) International Publication No. WO 98/55107 ("Shell 1998") alone, (2) Shell 1998 in combination with a 1993 article ("Papadimitriou"), and (3) Papadimitriou in combination with U.S. Patent No. 4,871,548. The Board concluded in its final written decision that claims 1, 3-5, and 11-13 were unpatentable as obvious in view of Shell 1998, and that claims 1, 3-5, and 10-13 were also unpatentable as obvious in view of Shell 1998 and Papadimitriou.
Depomed appealed the Board's determination to the Federal Circuit, Endo withdrew as a party to the appeal, and the Director of the USPTO intervened pursuant to 35 U.S.C. § 143. On appeal, Depomed argued that: (1) the Board erred in failing to account for the unexpected results of combining PEO and HPMC, (2) the Board's obviousness conclusion improperly relied on hindsight bias, and (3) the Board applied an incorrect legal standard to assess long-felt, but unmet, need.
With respect to Depomed's first argument, the Federal Circuit determined that substantial evidence supported the Board's finding that Depomed's evidence of unexpected results was weak and entitled to little weight. According to the opinion, the Board explained that Shell 1998 discloses a finite number of identified, predictable polymers that could be used individually or in combination, of which HPMC and PEO are "particularly preferred" polymers. In agreeing with the Board's conclusion that the claims are obvious in view of Shell 1998, the Board stated that:
Shell 1998 discloses (1) a finite number of matrix polymers, of which HPMC and PEO are preferred; (2) that matrix polymers "can be used individually or in combination"; and (3) that "[c]ertain combinations will often provide a more controlled release of the drug than their components when used individually." . . . The express disclosure that combinations of polymers will often yield better results than when used alone undermines Depomed's suggestion that the difference between using HPMC and PEO individually and using them in combination would not have been expected.
With respect to Depomed's second argument, the Federal Circuit disagreed with Depomed's assertion that a person of ordinary skill in the art would have had no motivation to combine HPMC and PEO because Shell 1998 discloses polymer combinations solely for the purpose of overcoming deficiencies in the controlled release properties of certain polymers in their individual capacities, and HPMC and PEO did not exhibit those deficiencies in their individual capacities. Instead, the Court agreed with the Board's finding that Shell 1998 "does not limit which polymers could be combined or suggest that certain polymers would not function properly in a combination matrix."
With respect to Depomed's third argument, the Federal Circuit agreed with Depomed's assertion that the Board incorrectly required evidence demonstrating a failure of others to establish a long-felt but unmet need. Nevertheless, the Court determined that substantial evidence supported the Board's assignment of little weight to Depomed's evidence of long-felt but unmet need, and agreed with the Board's ultimate conclusion that the claims are obvious in view of Shell 1998. The Court therefore determined that the Board did not err in holding claims 1, 3–5, and 10–13 of the '340 patent unpatentable as obvious, and affirmed the Board's decision.
Judge Reyna authored a concurring opinion to express two concerns. First, he noted that he was "troubled that the Board improperly employed a two-step approach in its obviousness analysis," explaining that the Board "first made initial conclusions of obviousness and only later considered Depomed's objective indicia of nonobviousness." Judge Reyna indicated that "[d]eferring consideration of objective indicia until after deciding a claim would have been obvious allows hindsight bias to creep into step one (the prima facie showing) and limits the meaningfulness of step two," adding that "in an IPR, the Board should not first make an obviousness determination only later to consider the patentee's objective indicia of nonobviousness," since "[d]oing so risks succumbing to the very hindsight bias." In Judge Reyna's view, the Board therefore erred by considering Depomed's objective indicia only after determining that certain claims would have been obvious.
Judge Reyna was also concerned with the Board's assignment of "weight" to the evidence, explaining that "results are either unexpected or they are not," and adding that "[o]ur case law does not ask whether results are 'really unexpected' or just a 'little unexpected.'" According to Judge Reyna, "[t]he Board must decide a binary issue: either the challenged claims would have been obvious or they would not have been obvious," and not "whether evidence of unexpected results 'outweighs' the similarity between the challenged claims and the prior art." However, despite these two concerns, Judge Reyna did not believe remand was necessary because "Depomed's objective indicia, even if analyzed under the proper framework, do not compel a conclusion of nonobviousness in view of Shell and Papadimitriou."
In re Depomed, Inc. (Fed. Cir. 2017)
Panel: Circuit Judges Dyk, Reyna, and Stoll
Opinion by Circuit Judge Stoll; concurring opinion by Circuit Judge Reyna