Rasuvo® Patent Survives IPR: Failure to Properly Frame Arguments Proves Fatal

February 9, 2018

The PTAB recently reminded Petitioners of the importance of properly framing prior art arguments, upholding all claims of U.S. Patent No. 8,664,231 in IPR2016-01370 in a final written decision issued yesterday.

The ’231 patent—covering Rasuvo®, a rheumatoid arthritis drug containing high doses of methotrexate formulated for subcutaneous injection—was challenged based on two primary references: Grint (a U.S. patent) and Wyeth (a pharmaceutical label for conventional uses of methotrexate).  The primary grounds for each reference were based on anticipation, and the PTAB determined that neither reference anticipated claim 1, the only independent claim of the ’231 patent.

No Anticipation Based on Grint

In short, the Petitioner (Koios Pharmaceuticals LLC) argued that Grint disclosed both "subcutaneous administration" and the particular high concentration of the claims.  The Patent Owner (medac GmbH) countered by arguing that the only reference to subcutaneous administration was in Example 1, and in that example, there was no discussion of concentration. Thus, although Grint described a concentration range that overlapped the claims of the '231 patent, this range was not associated with subcutaneous administration.  Koios attempted to bolster their argument by noting that medac's expert admitted at his deposition that he had thought of administering methotrexate in high concentrations, but did not have access to such solutions.

In determining that Grint did not anticipate claim 1, the PTAB agreed with medac that one skilled in the art would not have understood all concentrations disclosed in Grint to be applicable to subcutaneous administration.  This was supported by medoc's expert testimony regarding conventional practice (which relied on low concentrations).  The PTAB emphasized that Koios relied on the explicit teaching of Grint rather than arguing based on inherent anticipation or obviousness, and therefore Grint's disclosure of the methotrexate concentration and subcutaneous mode of administration must be "arranged as in the claim" in order to anticipate claim 1.  The PTAB also chastised Koios for relying on arguments only applicable to obviousness, noting that counsel argued "motivation" at oral argument (Decision at 20) and that medac's expert's testimony was also only pertinent to an obviousness argument (Decision at 25).  Accordingly, Grint was found not to anticipate claim 1, and other grounds relying on Grint in combination with other references were insufficient for the same reasons.

No Anticipation Based on Wyeth

Koios also argued anticipation based on Wyeth, noting that the label described subcutaneous administration, and was applicable to 1 gram vials that could be reconstituted to a concentration overlapping with the claims.  Koios's argument was that one skilled in the art would have deemed it safe to administer high concentrations of methotrexate subcutaneously based on the label.  medac's counterargument emphasized that Wyeth covers two different products, and the higher-concentration product was not described for subcutaneous use.

Again, the PTAB agreed with medac, determining that Koios's choice to rely only on the explicit disclosure of Wyeth (rather than arguing inherent anticipation or obviousness) was fatal.  In short, the two separate parts of Wyeth could not be combined to meet the limitations of claim 1 in an anticipation argument without a link between these disclosures.  And again, the PTAB noted that some of Koios's reasoning was relevant to an obviousness analysis, but inappropriate for anticipation (Decision at 41).  Accordingly, Wyeth was found not to anticipate claim 1, and other grounds relying on Wyeth in combination with other references were insufficient for the same reasons.


The PTAB's decision illustrates the importance of properly framing prior art arguments. Specifically, a single-ground obviousness rejection or anticipation based on inherency may be more robust than explicit anticipation.  The PTAB relied heavily on Net MoneyIn Inc. v. Verisign, Inc., a case standing for the proposition that distinct embodiments cannot be combined in a challenge based on anticipation.  545 F.3d 1359, 1369 (Fed. Cir. 2008) (“it is not enough that the prior art reference … includes multiple, distinct teachings that the artisan might somehow combine to achieve the claimed invention.”)  Accordingly, in view of the PTAB's reasoning, the safest approach would be for Petitioners to propose obviousness grounds rather than anticipation—particularly where separate (or arguably separate) embodiments are relied upon.  By the same token, Patent Owners should consider attacking anticipation grounds on this basis, if possible.

Here, a single-reference obviousness ground would have allowed Koios to rely on some of the additional arguments it made, and those arguments may have been enough to tip the scale towards unpatentability.