On May 20, 2019, the PTAB denied a request for rehearing in Apotex Inc. v. Amgen Inc., Case IPR2016-01542 (Paper 67), but modified its Final Written Decision. In the Final Written Decision, the PTAB found claims 1-17 and 19-24 of U.S. Patent No. 8,952,138 (“the ’138 patent”) unpatentable. The ’138 patent is directed towards a method of refolding a protein expressed in a non-mammalian expression system. Only claim 18 was found patentable, which depends from claim 1 and recites that “the incubation is performed under non-aerobic conditions.”

In its request for rehearing, Apotex asserted that the grounds for rehearing were the PTAB’s interpretation of the claim term “non-aerobic conditions” and the PTAB incorrectly concluded that Apotex failed to demonstrate that claim 18 was unpatentable. The PTAB ordered additional briefing including an opposition to the request for rehearing and briefs from both parties regarding the meaning of the claim term “non-aerobic conditions.”

Apotex argued that the PTAB adopted an erroneous construction of the term “non-aerobic conditions” and that the specification provides a special definition for the term. The specification provides that the term means “any reaction or incubation condition that is performed without intentional aeration of the mixture by mechanical or chemical means.” Paper 67 at 3. The PTAB agreed that it overlooked the special definition in the specification but concluded that the Apotex did not include a proposed construction for “non-aerobic conditions” in its Petition. Apotex argued that its Petition addressed the construction through its statement that “the challenged claims must be given their broadest reasonable interpretations in light of the specification of the ’138 patent. To be clear, any claim terms not included in the following discussion should be given their broadest reasonable construction in light of the specification.” Paper 67 at 4-5. The PTAB disagreed, concluding that the statement does not specifically point it to the special definition of the claim term and instead treats the term as having its plain and ordinary meaning.  The PTAB argued that “non-aerobic” means “the absence of oxygen” when not given a special meaning.

The PTAB then examined various portions of the Petition and expert declaration cited by the Apotex as providing support for its argument that it addressed the issue of the special construction of “non-aerobic conditions.” However, the PTAB was not persuaded. The PTAB argued that there is nothing in the expert declaration suggesting that a special definition for “non-aerobic conditions” existed. The PTAB argued that Apotex’s statement in the Petition that it would have been obvious to “eliminate oxygen from the refolding reaction” was the clearest statement indicating that Apotex meant for “non-aerobic conditions” to mean the elimination of or absence of oxygen. However, it was not enough.  Amgen argued in its Opposition that Apotex’s Request for Rehearing was based on arguments not present its Petition or Reply and the PTAB agreed. Because Apotex failed to demonstrate where the claim construction issue was presented to the PTAB, the PTAB denied the request for rehearing.

However, the PTAB still decided to address the issue of claim construction of “non-aerobic conditions” in view of the additional briefing. The PTAB stated that it requested additional briefing “because the term is expressly defined and we wish to ensure the decision is legally accurate and each party has had adequate opportunity to provide input on the broadest reasonable interpretation of the term.” Paper 67 at 11.

Both parties agreed that the meaning of “non-aerobic conditions” is the express definition provided in the specification. In view of the agreed upon definition, the PTAB then decided to modify its Final Written Decision as it pertains to claim 18. Generally, courts have held that administrative agencies “possess inherent authority to reconsider their decisions, subject to certain limitations, regardless of whether they possess explicit statutory authority to do so.”  Paper 67 at 11 (citing Tokyo Kikai Seisakusho, Ltd. v. United States, 529 F.3d 1352, 1360-61 (Fed. Cir. 2008)). Using the special definition of “non-aerobic conditions”, the PTAB concluded that claim 18 only requires that a reaction be performed without the intentional aeration of the mixture by chemical or mechanical means and because the two prior art references cited by Apotex do not describe intentional aeration, they meet the requirement of claim 18. The PTAB concluded that Apotex demonstrated claim 18 is unpatentable as obvious in view of the prior art and modified its previous decision to reflect this conclusion.