In a recent appeal from a PTAB final written decision, the Federal Circuit reversed the Board’s determination that all claims of a Duke patent were unpatentable (Duke Univ. v. BioMarin Pharm. Inc., Appeal No. 2016-1106 (Fed. Cir., April 25, 2017). The court concluded that certain of the Board’s claim constructions were incorrect, and that others, while appropriate, were mis-applied and reversed the Board’s decision on anticipation, as well as obviousness of some claims.

This case is the third in a series of IPRs BioMarin filed against patents owned by Genzyme and Duke University (“Duke”) related to the treatment of glycogen storage disease type II, e.g., Pompe’s disease, as discussed in a previous blog. Duke’s U.S. Patent 7,056,712 is directed to the treatment of glycogen storage disease type II by administration of a recombinant human acid alpha glucosidase (GAA) protein. BioMarin successfully petitioned the PTAB to institute inter partes review, asserting claims 1-9, 11, 12, 15, and 18-21 of Duke’s patent were invalid as anticipated by or obvious in view of several prior art publications (IPR2013-00535).

Claims 1 and 20 recite a method of treating glycogen storage disease type II by administering GAA made from CHO cells. Dependent claim 9 recites administration of the precursor form of the protein. Dependent claim 19 recites administration of GAA in conjunction with an immunosuppressant, wherein the immunosuppressant is administered prior to any administration of human GAA. Petitioner asserted that claims 1-9, 12, 15, and 20-21 were anticipated by van Bree, which disclosed recombinant GAA and administration of GAA to treat the particular lysosomal storage disease. Petitioner also asserted that the claims were obvious in view of Reuser and van Hove, further in view of Brady.

In its final written decision, the PTAB concluded that claims 1-9, 12, 15, and 20-21 were anticipated by van Bree, finding that van Bree disclosed administration of GAA that could be made by CHO cells, that the GAA could be a mixture of precursor and mature enzyme forms, and that the claims encompassed administration of any mixture of precursor and mature forms of the enzyme. The PTAB concluded that claims 1-9, 11, 12, 15, and 20-21 would have been obvious in view of Reuser and Van Hove, finding that the combination of these publications taught administration of GAA made by CHO cells. The PTAB concluded that claims 18 and 19 would have been obvious over the same combination in view of Brady, which described administration of an immunosuppressant to patients that develop an immune response to enzyme replacement therapy. In reaching a conclusion of obviousness for claim 19, the Board interpreted the claim term ”wherein the immunosuppressant is administered prior to any administration” of human GAA to refer to administration of an immunosuppressant prior to the first administration of GAA. However, the Board determined that Brady teaches administration of the immunosuppressant on day 1 and prior to any subsequent administration. The PTAB’s final written determination accordingly canceled all of the challenged claims.

On Duke’s rehearing request, the PTAB stated that Brady does not disclose administering an immunosuppressant prior to any and all administrations of hGAA but, nevertheless concluded that claim 19 would have been obvious in view of Reuser, Van Hove, and Brady (Rehearing Decision, 2015 WL 4467381).

On appeal, the Federal Circuit first considered the anticipation issue and maintained that the Board’s treatment of claims 1-8, 12, 15, and 21 was correct and the claims are invalid as anticipated. Because Duke did not argue separately for patentability of claims 18 and 20, these claims were also unpatentable as anticipated. The court reversed, however, the PTAB’s decision that claim 9 was anticipated. According to the Court, the claim 9 term “precursor,” interpreted in light of the specification, is limited to administration of only the precursor form of the enzyme, which was not disclosed in the art.

The Court next considered the obviousness challenge to claims 1-9, 12, 15, and 18-21. The Court held that despite their application of the term “precursor” to refer to use of only the precursor form of GAA, claims 1-8, 12, 15 and 20-21 were still held to be obvious in view of the cited art. However, because claim 9 was never analyzed in view of this interpretation during the IPR, the court remanded the question of obviousness of claim 9 to the PTAB for further consideration.

In reviewing the PTAB’s conclusion that claim 19 would have been obvious, the court determined substantial evidence supports the PTAB’s finding that the cited art does not disclose administration of an immunosuppressant before any and all enzyme administrations. But, according to the court, the PTAB improperly determined that one of skill would have arrived at the claimed administration as a predictable variation of the cited art. Specifically, the court determined that “the expert testimony relied on by the Board to bridge the gap between the disclosure in Brady and claim 19 falls short of what would have rendered the subject matter of claim 9 obvious.” The Court concluded that the art does not disclose or suggest prophylactic administration of an immunosuppressant prior to any and all use of the GAA and, in the absence of further evidence, the administration in claim 19 would not have been obvious. Accordingly, the court reversed the Board’s decision that claim 19 would have been obvious.

The Federal Circuit’s reconsideration of the Board’s claim construction and application of the cited art in this decision is a further example of how evidentiary evidence of the parties played a relevant role in construing claim terms and the ultimate outcome of the case.